diff --git a/CHANGELOG.next.asciidoc b/CHANGELOG.next.asciidoc
index 80fead3fb4c..00383fb51cf 100644
--- a/CHANGELOG.next.asciidoc
+++ b/CHANGELOG.next.asciidoc
@@ -243,6 +243,8 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 
 *Packetbeat*
 
+- Prevent incorrect use of AMQP protocol parsing from causing silent failure. {pull}29017[29017]
+- Fix error handling in MongoDB protocol parsing. {pull}29017[29017]
 
 *Winlogbeat*
 
diff --git a/packetbeat/cmd/root.go b/packetbeat/cmd/root.go
index 808de836fb3..6032089c9fc 100644
--- a/packetbeat/cmd/root.go
+++ b/packetbeat/cmd/root.go
@@ -50,7 +50,7 @@ var RootCmd *cmd.BeatsRootCmd
 
 // PacketbeatSettings contains the default settings for packetbeat
 func PacketbeatSettings() instance.Settings {
-	var runFlags = pflag.NewFlagSet(Name, pflag.ExitOnError)
+	runFlags := pflag.NewFlagSet(Name, pflag.ExitOnError)
 	runFlags.AddGoFlag(flag.CommandLine.Lookup("I"))
 	runFlags.AddGoFlag(flag.CommandLine.Lookup("t"))
 	runFlags.AddGoFlag(flag.CommandLine.Lookup("O"))
diff --git a/packetbeat/config/agent.go b/packetbeat/config/agent.go
index 36e3c977b44..34df1721597 100644
--- a/packetbeat/config/agent.go
+++ b/packetbeat/config/agent.go
@@ -66,7 +66,7 @@ func (i agentInput) addProcessorsAndIndex(cfg *common.Config) (*common.Config, e
 	mergeConfig, err := common.NewConfigFrom(common.MapStr{
 		"index": datastreamConfig.Datastream.Type + "-" + datastreamConfig.Datastream.Dataset + "-" + namespace,
 		"processors": append([]common.MapStr{
-			common.MapStr{
+			{
 				"add_fields": common.MapStr{
 					"target": "data_stream",
 					"fields": common.MapStr{
@@ -76,7 +76,7 @@ func (i agentInput) addProcessorsAndIndex(cfg *common.Config) (*common.Config, e
 					},
 				},
 			},
-			common.MapStr{
+			{
 				"add_fields": common.MapStr{
 					"target": "event",
 					"fields": common.MapStr{
diff --git a/packetbeat/decoder/decoder.go b/packetbeat/decoder/decoder.go
index 50e8f595481..ae8eeb9d84b 100644
--- a/packetbeat/decoder/decoder.go
+++ b/packetbeat/decoder/decoder.go
@@ -87,7 +87,8 @@ func New(
 	d := Decoder{
 		flows:     f,
 		decoders:  make(map[gopacket.LayerType]gopacket.DecodingLayer),
-		icmp4Proc: icmp4, icmp6Proc: icmp6, tcpProc: tcp, udpProc: udp}
+		icmp4Proc: icmp4, icmp6Proc: icmp6, tcpProc: tcp, udpProc: udp,
+	}
 	d.stD1Q.init(&d.d1q[0], &d.d1q[1])
 	d.stIP4.init(&d.ip4[0], &d.ip4[1])
 	d.stIP6.init(&d.ip6[0], &d.ip6[1])
diff --git a/packetbeat/flows/flows_test.go b/packetbeat/flows/flows_test.go
index 601613e61d1..9cee1c59e2d 100644
--- a/packetbeat/flows/flows_test.go
+++ b/packetbeat/flows/flows_test.go
@@ -56,12 +56,16 @@ func TestFlowsCounting(t *testing.T) {
 	assert.NoError(t, err)
 
 	uint1, err := module.NewUint("uint1")
+	assert.NoError(t, err)
 	uint2, err := module.NewUint("uint2")
+	assert.NoError(t, err)
 	int1, err := module.NewInt("int1")
+	assert.NoError(t, err)
 	int2, err := module.NewInt("int2")
+	assert.NoError(t, err)
 	float1, err := module.NewFloat("float1")
+	assert.NoError(t, err)
 	float2, err := module.NewFloat("float2")
-
 	assert.NoError(t, err)
 
 	pub := &flowsChan{make(chan []beat.Event, 1)}
diff --git a/packetbeat/flows/worker.go b/packetbeat/flows/worker.go
index f0080cf68d2..b339a75fa4d 100644
--- a/packetbeat/flows/worker.go
+++ b/packetbeat/flows/worker.go
@@ -107,7 +107,7 @@ func makeWorker(
 		if align > 0 {
 			// round time to nearest 10 seconds for alignment
 			aligned := time.Unix(((time.Now().Unix()+(align-1))/align)*align, 0)
-			waitStart := aligned.Sub(time.Now())
+			waitStart := time.Until(aligned)
 			debugf("worker wait start(%v): %v", aligned, waitStart)
 			if cont := w.sleep(waitStart); !cont {
 				return
diff --git a/packetbeat/flows/worker_test.go b/packetbeat/flows/worker_test.go
index 3bec75f2fe3..520d107f9ab 100644
--- a/packetbeat/flows/worker_test.go
+++ b/packetbeat/flows/worker_test.go
@@ -33,10 +33,8 @@ import (
 	"github.com/elastic/beats/v7/packetbeat/procs"
 )
 
-var (
-	// Use `go test -data` to update sample event files.
-	dataFlag = flag.Bool("data", false, "Write updated data.json files")
-)
+// Use `go test -data` to update sample event files.
+var dataFlag = flag.Bool("data", false, "Write updated data.json files")
 
 func TestCreateEvent(t *testing.T) {
 	logp.TestingSetup()
@@ -124,7 +122,7 @@ func TestCreateEvent(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		if err := ioutil.WriteFile("../_meta/sample_outputs/flow.json", output, 0644); err != nil {
+		if err := ioutil.WriteFile("../_meta/sample_outputs/flow.json", output, 0o644); err != nil {
 			t.Fatal(err)
 		}
 	}
diff --git a/packetbeat/pb/event.go b/packetbeat/pb/event.go
index 683e22253be..4ba7e4acf15 100644
--- a/packetbeat/pb/event.go
+++ b/packetbeat/pb/event.go
@@ -237,14 +237,14 @@ func (f *Fields) ComputeValues(localIPs []net.IP, internalNetworks []string) err
 	}
 
 	// network.community_id
-	switch {
-	case f.Network.Transport == "udp":
+	switch f.Network.Transport {
+	case "udp":
 		flow.Protocol = 17
-	case f.Network.Transport == "tcp":
+	case "tcp":
 		flow.Protocol = 6
-	case f.Network.Transport == "icmp":
+	case "icmp":
 		flow.Protocol = 1
-	case f.Network.Transport == "ipv6-icmp":
+	case "ipv6-icmp":
 		flow.Protocol = 58
 	}
 	flow.ICMP.Type = f.ICMPType
diff --git a/packetbeat/processor/add_kubernetes_metadata/indexers.go b/packetbeat/processor/add_kubernetes_metadata/indexers.go
index 474f111e97f..3e547e3a8c1 100644
--- a/packetbeat/processor/add_kubernetes_metadata/indexers.go
+++ b/packetbeat/processor/add_kubernetes_metadata/indexers.go
@@ -26,14 +26,14 @@ func init() {
 	// Register default indexers
 	cfg := common.NewConfig()
 
-	//Add IP Port Indexer as a default indexer
+	// Add IP Port Indexer as a default indexer
 	kubernetes.Indexing.AddDefaultIndexerConfig(kubernetes.IPPortIndexerName, *cfg)
 
 	formatCfg, err := common.NewConfigFrom(map[string]interface{}{
 		"format": "%{[ip]}:%{[port]}",
 	})
 	if err == nil {
-		//Add field matcher with field to lookup as metricset.host
+		// Add field matcher with field to lookup as metricset.host
 		kubernetes.Indexing.AddDefaultMatcherConfig(kubernetes.FieldFormatMatcherName, *formatCfg)
 	}
 }
diff --git a/packetbeat/procs/procs.go b/packetbeat/procs/procs.go
index bf3daab9ff2..a3d031ec72f 100644
--- a/packetbeat/procs/procs.go
+++ b/packetbeat/procs/procs.go
@@ -213,7 +213,7 @@ func (proc *ProcessesWatcher) updateMap(transport applayer.Transport) {
 	if logp.HasSelector("procsdetailed") {
 		start := time.Now()
 		defer func() {
-			logp.Debug("procsdetailed", "updateMap() took %v", time.Now().Sub(start))
+			logp.Debug("procsdetailed", "updateMap() took %v", time.Since(start))
 		}()
 	}
 
diff --git a/packetbeat/procs/procs_linux_test.go b/packetbeat/procs/procs_linux_test.go
index 39c8a937741..e36bd50a208 100644
--- a/packetbeat/procs/procs_linux_test.go
+++ b/packetbeat/procs/procs_linux_test.go
@@ -39,14 +39,14 @@ func createFakeDirectoryStructure(prefix string, files []testProcFile) error {
 	var err error
 	for _, file := range files {
 		dir := filepath.Dir(file.path)
-		err = os.MkdirAll(filepath.Join(prefix, dir), 0755)
+		err = os.MkdirAll(filepath.Join(prefix, dir), 0o755)
 		if err != nil {
 			return err
 		}
 
 		if !file.isLink {
 			err = ioutil.WriteFile(filepath.Join(prefix, file.path),
-				[]byte(file.contents), 0644)
+				[]byte(file.contents), 0o644)
 			if err != nil {
 				return err
 			}
diff --git a/packetbeat/procs/procs_windows.go b/packetbeat/procs/procs_windows.go
index 50807691efa..ee3eee1a28d 100644
--- a/packetbeat/procs/procs_windows.go
+++ b/packetbeat/procs/procs_windows.go
@@ -42,13 +42,17 @@ type extractor interface {
 	Size() int
 }
 
-type callbackFn func(net.IP, uint16, int)
-type extractorFactory func(fn callbackFn) extractor
+type (
+	callbackFn       func(net.IP, uint16, int)
+	extractorFactory func(fn callbackFn) extractor
+)
 
-type tcpRowOwnerPIDExtractor callbackFn
-type tcp6RowOwnerPIDExtractor callbackFn
-type udpRowOwnerPIDExtractor callbackFn
-type udp6RowOwnerPIDExtractor callbackFn
+type (
+	tcpRowOwnerPIDExtractor  callbackFn
+	tcp6RowOwnerPIDExtractor callbackFn
+	udpRowOwnerPIDExtractor  callbackFn
+	udp6RowOwnerPIDExtractor callbackFn
+)
 
 var tablesByTransport = map[applayer.Transport][]struct {
 	family    uint32
diff --git a/packetbeat/procs/procs_windows_test.go b/packetbeat/procs/procs_windows_test.go
index 51cc8391d68..4abfe359b71 100644
--- a/packetbeat/procs/procs_windows_test.go
+++ b/packetbeat/procs/procs_windows_test.go
@@ -42,21 +42,33 @@ func TestParseTableRaw(t *testing.T) {
 		expected []portProcMapping
 		mustErr  bool
 	}{
-		{"Empty table IPv4", IPv4,
-			"00000000", nil, false},
-		{"Empty table IPv6", IPv6,
-			"00000000", nil, false},
-		{"Short table (no length)", IPv4,
-			"000000", nil, true},
-		{"Short table (partial entry)", IPv6,
-			"01000000AAAAAAAAAAAAAAAAAAAA", nil, true},
-		{"One entry (IPv4)", IPv4,
+		{
+			"Empty table IPv4", IPv4,
+			"00000000", nil, false,
+		},
+		{
+			"Empty table IPv6", IPv6,
+			"00000000", nil, false,
+		},
+		{
+			"Short table (no length)", IPv4,
+			"000000", nil, true,
+		},
+		{
+			"Short table (partial entry)", IPv6,
+			"01000000AAAAAAAAAAAAAAAAAAAA", nil, true,
+		},
+		{
+			"One entry (IPv4)", IPv4,
 			"01000000" +
 				"77777777AAAAAAAA12340000BBBBBBBBFFFF0000CCCCCCCC",
 			[]portProcMapping{
 				{endpoint: endpoint{address: "170.170.170.170", port: 0x1234}, pid: int(pid)},
-			}, false},
-		{"Two entries (IPv6)", IPv6,
+			},
+			false,
+		},
+		{
+			"Two entries (IPv6)", IPv6,
 			"02000000" +
 				// First entry
 				"11112222333344445555666677778888F0F0F0F0" +
@@ -76,7 +88,9 @@ func TestParseTableRaw(t *testing.T) {
 			[]portProcMapping{
 				{endpoint: endpoint{address: "1111:2222:3333:4444:5555:6666:7777:8888", port: 0xABCD}, pid: 1},
 				{endpoint: endpoint{address: "aaaa:aaaa:aaaa:aaaa:aaaa:aaaa:aaaa:aaaa", port: 0}, pid: 0xffff},
-			}, false},
+			},
+			false,
+		},
 	} {
 		msg := fmt.Sprintf("Test case #%d: %s", idx+1, testCase.name)
 		table, err := hex.DecodeString(testCase.raw)
diff --git a/packetbeat/procs/zsyscall_windows.go b/packetbeat/procs/zsyscall_windows.go
index b313698211e..f938c08f792 100644
--- a/packetbeat/procs/zsyscall_windows.go
+++ b/packetbeat/procs/zsyscall_windows.go
@@ -34,9 +34,7 @@ const (
 	errnoERROR_IO_PENDING = 997
 )
 
-var (
-	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
-)
+var errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
 
 // errnoErr returns common boxed Errno values, to prevent
 // allocations at runtime.
diff --git a/packetbeat/protos/amqp/amqp.go b/packetbeat/protos/amqp/amqp.go
index f0c1e26dd28..2402b9150e3 100644
--- a/packetbeat/protos/amqp/amqp.go
+++ b/packetbeat/protos/amqp/amqp.go
@@ -50,7 +50,7 @@ type amqpPlugin struct {
 	results                   protos.Reporter
 	watcher                   procs.ProcessesWatcher
 
-	//map containing functions associated with different method numbers
+	// map containing functions associated with different method numbers
 	methodMap map[codeClass]map[codeMethod]amqpMethod
 }
 
@@ -87,7 +87,7 @@ func (amqp *amqpPlugin) init(results protos.Reporter, watcher procs.ProcessesWat
 	amqp.initMethodMap()
 	amqp.setFromConfig(config)
 
-	if amqp.hideConnectionInformation == false {
+	if !amqp.hideConnectionInformation {
 		amqp.addConnectionMethods()
 	}
 	amqp.transactions = common.NewCache(
@@ -194,8 +194,8 @@ func (amqp *amqpPlugin) ConnectionTimeout() time.Duration {
 }
 
 func (amqp *amqpPlugin) Parse(pkt *protos.Packet, tcptuple *common.TCPTuple,
-	dir uint8, private protos.ProtocolData) protos.ProtocolData {
-
+	dir uint8, private protos.ProtocolData,
+) protos.ProtocolData {
 	defer logp.Recover("ParseAmqp exception")
 	detailedf("Parse method triggered")
 
@@ -284,7 +284,7 @@ func (amqp *amqpPlugin) handleAmqpRequest(msg *amqpMessage) {
 	} else {
 		trans.request = msg.method
 	}
-	//length = message + 4 bytes header + frame end octet
+	// length = message + 4 bytes header + frame end octet
 	trans.bytesIn = msg.bodySize + 12
 	if msg.fields != nil {
 		trans.amqp = msg.fields
@@ -292,9 +292,9 @@ func (amqp *amqpPlugin) handleAmqpRequest(msg *amqpMessage) {
 		trans.amqp = common.MapStr{}
 	}
 
-	//if error or exception, publish it now. sometimes client or server never send
-	//an ack message and the error is lost. Also, if nowait flag set, don't expect
-	//any response and publish
+	// if error or exception, publish it now. sometimes client or server never send
+	// an ack message and the error is lost. Also, if nowait flag set, don't expect
+	// any response and publish
 	if isAsynchronous(trans) {
 		amqp.publishTransaction(trans)
 		debugf("Amqp transaction completed")
@@ -317,9 +317,9 @@ func (amqp *amqpPlugin) handleAmqpResponse(msg *amqpMessage) {
 		return
 	}
 
-	//length = message + 4 bytes class/method + frame end octet + header
+	// length = message + 4 bytes class/method + frame end octet + header
 	trans.bytesOut = msg.bodySize + 12
-	//merge the both fields from request and response
+	// merge the both fields from request and response
 	trans.amqp.Update(msg.fields)
 	trans.response = common.OK_STATUS
 
@@ -344,8 +344,8 @@ func (amqp *amqpPlugin) handleAmqpResponse(msg *amqpMessage) {
 func (amqp *amqpPlugin) expireTransaction(trans *amqpTransaction) {
 	debugf("Transaction expired")
 
-	//possibility of a connection.close or channel.close method that didn't get an
-	//ok answer. Let's publish it.
+	// possibility of a connection.close or channel.close method that didn't get an
+	// ok answer. Let's publish it.
 	if isCloseError(trans) {
 		trans.notes = append(trans.notes, "Close-ok method not received by sender")
 		amqp.publishTransaction(trans)
@@ -354,8 +354,8 @@ func (amqp *amqpPlugin) expireTransaction(trans *amqpTransaction) {
 	amqp.transactions.Delete(trans.tuple.Hashable())
 }
 
-//This method handles published messages from clients. Being an async
-//process, the method, header and body frames are regrouped in one transaction
+// This method handles published messages from clients. Being an async
+// process, the method, header and body frames are regrouped in one transaction
 func (amqp *amqpPlugin) handlePublishing(client *amqpMessage) {
 	tuple := client.tcpTuple
 	trans := amqp.getTransaction(tuple.Hashable())
@@ -369,8 +369,8 @@ func (amqp *amqpPlugin) handlePublishing(client *amqpMessage) {
 	trans.src, trans.dst = common.MakeEndpointPair(client.tcpTuple.BaseTuple, client.cmdlineTuple)
 
 	trans.method = client.method
-	//for publishing and delivering, bytes in and out represent the length of the
-	//message itself
+	// for publishing and delivering, bytes in and out represent the length of the
+	// message itself
 	trans.bytesIn = client.bodySize
 
 	if client.bodySize > uint64(amqp.maxBodyLength) {
@@ -384,13 +384,13 @@ func (amqp *amqpPlugin) handlePublishing(client *amqpMessage) {
 	trans.amqp = client.fields
 	amqp.publishTransaction(trans)
 	debugf("Amqp transaction completed")
-	//delete trans from map
+	// delete trans from map
 	amqp.transactions.Delete(trans.tuple.Hashable())
 }
 
-//This method handles delivered messages via basic.deliver and basic.get-ok AND
-//returned messages to clients. Being an async process, the method, header and
-//body frames are regrouped in one transaction
+// This method handles delivered messages via basic.deliver and basic.get-ok AND
+// returned messages to clients. Being an async process, the method, header and
+// body frames are regrouped in one transaction
 func (amqp *amqpPlugin) handleDelivering(server *amqpMessage) {
 	tuple := server.tcpTuple
 	trans := amqp.getTransaction(tuple.Hashable())
@@ -403,8 +403,8 @@ func (amqp *amqpPlugin) handleDelivering(server *amqpMessage) {
 	trans.ts = server.ts
 	trans.src, trans.dst = common.MakeEndpointPair(server.tcpTuple.BaseTuple, server.cmdlineTuple)
 
-	//for publishing and delivering, bytes in and out represent the length of the
-	//message itself
+	// for publishing and delivering, bytes in and out represent the length of the
+	// message itself
 	trans.bytesOut = server.bodySize
 
 	if server.bodySize > uint64(amqp.maxBodyLength) {
@@ -422,7 +422,7 @@ func (amqp *amqpPlugin) handleDelivering(server *amqpMessage) {
 
 	amqp.publishTransaction(trans)
 	debugf("Amqp transaction completed")
-	//delete trans from map
+	// delete trans from map
 	amqp.transactions.Delete(trans.tuple.Hashable())
 }
 
@@ -459,7 +459,7 @@ func (amqp *amqpPlugin) publishTransaction(t *amqpTransaction) {
 		fields["user.id"] = userID
 	}
 
-	//let's try to convert request/response to a readable format
+	// let's try to convert request/response to a readable format
 	if amqp.sendRequest {
 		if t.method == "basic.publish" {
 			if t.toString {
@@ -503,7 +503,7 @@ func (amqp *amqpPlugin) publishTransaction(t *amqpTransaction) {
 	amqp.results(evt)
 }
 
-//function to check if method is async or not
+// function to check if method is async or not
 func isAsynchronous(trans *amqpTransaction) bool {
 	if val, ok := trans.amqp["no-wait"]; ok && val == true {
 		return true
@@ -514,7 +514,7 @@ func isAsynchronous(trans *amqpTransaction) bool {
 		trans.method == "basic.nack"
 }
 
-//function to convert a body slice into a readable format
+// function to convert a body slice into a readable format
 func bodyToString(data []byte) string {
 	ret := make([]string, len(data))
 	for i, c := range data {
@@ -523,7 +523,7 @@ func bodyToString(data []byte) string {
 	return strings.Join(ret, " ")
 }
 
-//function used to check if a body message can be converted to readable string
+// function used to check if a body message can be converted to readable string
 func isStringable(m *amqpMessage) bool {
 	stringable := false
 
diff --git a/packetbeat/protos/amqp/amqp_fields.go b/packetbeat/protos/amqp/amqp_fields.go
index ff4f7c382b5..d7536572978 100644
--- a/packetbeat/protos/amqp/amqp_fields.go
+++ b/packetbeat/protos/amqp/amqp_fields.go
@@ -28,9 +28,9 @@ import (
 	"github.com/elastic/beats/v7/libbeat/logp"
 )
 
+// getTable updates fields with the table data at the given offset.
+// fields must be non_nil on entry.
 func getTable(fields common.MapStr, data []byte, offset uint32) (next uint32, err bool, exists bool) {
-	ret := common.MapStr{}
-
 	length := binary.BigEndian.Uint32(data[offset : offset+4])
 
 	// size declared too big
@@ -39,23 +39,20 @@ func getTable(fields common.MapStr, data []byte, offset uint32) (next uint32, er
 	}
 	if length > 0 {
 		exists = true
-		err := fieldUnmarshal(ret, data[offset+4:offset+4+length], 0, length, -1)
+		table := common.MapStr{}
+		err := fieldUnmarshal(table, data[offset+4:offset+4+length], 0, length, -1)
 		if err {
 			logp.Warn("Error while parsing a field table")
 			return 0, true, false
 		}
-		if fields == nil {
-			fields = ret
-		} else {
-			fields.Update(ret)
-		}
+		fields.Update(table)
 	}
 	return length + 4 + offset, false, exists
 }
 
+// getTable updates fields with the array data at the given offset.
+// fields must be non_nil on entry.
 func getArray(fields common.MapStr, data []byte, offset uint32) (next uint32, err bool, exists bool) {
-	ret := common.MapStr{}
-
 	length := binary.BigEndian.Uint32(data[offset : offset+4])
 
 	// size declared too big
@@ -64,30 +61,27 @@ func getArray(fields common.MapStr, data []byte, offset uint32) (next uint32, er
 	}
 	if length > 0 {
 		exists = true
-		err := fieldUnmarshal(ret, data[offset+4:offset+4+length], 0, length, 0)
+		array := common.MapStr{}
+		err := fieldUnmarshal(array, data[offset+4:offset+4+length], 0, length, 0)
 		if err {
 			logp.Warn("Error while parsing a field array")
 			return 0, true, false
 		}
-		if fields == nil {
-			fields = ret
-		} else {
-			fields.Update(ret)
-		}
+		fields.Update(array)
 	}
 	return length + 4 + offset, false, exists
 }
 
-//The index parameter, when set at -1, indicates that the entry is a field table.
-//If it's set at 0, it is an array.
+// The index parameter, when set at -1, indicates that the entry is a field table.
+// If it's set at 0, it is an array.
 func fieldUnmarshal(table common.MapStr, data []byte, offset uint32, length uint32, index int) (err bool) {
 	var name string
 
 	if offset >= length {
 		return false
 	}
-	//get name of the field. If it's an array, it will be the index parameter as a
-	//string. If it's a table, it will be the name of the field.
+	// get name of the field. If it's an array, it will be the index parameter as a
+	// string. If it's a table, it will be the name of the field.
 	if index < 0 {
 		fieldName, offsetTemp, err := getShortString(data, offset+1, uint32(data[offset]))
 		if err {
@@ -199,10 +193,10 @@ func fieldUnmarshal(table common.MapStr, data []byte, offset uint32, length uint
 		table[name] = bodyToByteArray(data[offset+1+size : offset+5+size])
 		offset += 5 + size
 	default:
-		//unknown field
+		// unknown field
 		return true
 	}
-	//advance to next field recursively
+	// advance to next field recursively
 	return fieldUnmarshal(table, data, offset, length, index)
 }
 
diff --git a/packetbeat/protos/amqp/amqp_methods.go b/packetbeat/protos/amqp/amqp_methods.go
index 93cec5f2747..d74148026c5 100644
--- a/packetbeat/protos/amqp/amqp_methods.go
+++ b/packetbeat/protos/amqp/amqp_methods.go
@@ -32,7 +32,7 @@ func connectionStartMethod(m *amqpMessage, args []byte) (bool, bool) {
 	properties := make(common.MapStr)
 	next, err, exists := getTable(properties, args, 2)
 	if err {
-		//failed to get de peer-properties, size may be wrong, let's quit
+		// failed to get de peer-properties, size may be wrong, let's quit
 		logp.Warn("Failed to parse server properties in connection.start method")
 		return false, false
 	}
@@ -54,7 +54,7 @@ func connectionStartMethod(m *amqpMessage, args []byte) (bool, bool) {
 		"mechanisms":    mechanisms,
 		"locales":       locales,
 	}
-	//if there is a server properties table, add it
+	// if there is a server properties table, add it
 	if exists {
 		m.fields["server-properties"] = properties
 	}
@@ -65,7 +65,7 @@ func connectionStartOkMethod(m *amqpMessage, args []byte) (bool, bool) {
 	properties := make(common.MapStr)
 	next, err, exists := getTable(properties, args, 0)
 	if err {
-		//failed to get de peer-properties, size may be wrong, let's quit
+		// failed to get de peer-properties, size may be wrong, let's quit
 		logp.Warn("Failed to parse server properties in connection.start method")
 		return false, false
 	}
@@ -89,7 +89,7 @@ func connectionStartOkMethod(m *amqpMessage, args []byte) (bool, bool) {
 		"mechanism": mechanism,
 		"locale":    locale,
 	}
-	//if there is a client properties table, add it
+	// if there is a client properties table, add it
 	if exists {
 		m.fields["client-properties"] = properties
 	}
@@ -99,8 +99,8 @@ func connectionStartOkMethod(m *amqpMessage, args []byte) (bool, bool) {
 func connectionTuneMethod(m *amqpMessage, args []byte) (bool, bool) {
 	m.isRequest = true
 	m.method = "connection.tune"
-	//parameters are not parsed here, they are further negotiated by the server
-	//in the connection.tune-ok method
+	// parameters are not parsed here, they are further negotiated by the server
+	// in the connection.tune-ok method
 	return true, true
 }
 
@@ -163,7 +163,7 @@ func channelCloseMethod(m *amqpMessage, args []byte) (bool, bool) {
 	return true, true
 }
 
-//function to fetch fields from channel close and connection close
+// function to fetch fields from channel close and connection close
 func getCloseInfo(args []byte, m *amqpMessage) bool {
 	code := binary.BigEndian.Uint16(args[0:2])
 	m.isRequest = true
@@ -411,7 +411,7 @@ func exchangeDeleteMethod(m *amqpMessage, args []byte) (bool, bool) {
 	return true, true
 }
 
-//this is a method exclusive to RabbitMQ
+// this is a method exclusive to RabbitMQ
 func exchangeBindMethod(m *amqpMessage, args []byte) (bool, bool) {
 	m.method = "exchange.bind"
 	err := exchangeBindUnbindInfo(m, args)
@@ -421,7 +421,7 @@ func exchangeBindMethod(m *amqpMessage, args []byte) (bool, bool) {
 	return true, true
 }
 
-//this is a method exclusive to RabbitMQ
+// this is a method exclusive to RabbitMQ
 func exchangeUnbindMethod(m *amqpMessage, args []byte) (bool, bool) {
 	m.method = "exchange.unbind"
 	err := exchangeBindUnbindInfo(m, args)
@@ -588,7 +588,7 @@ func basicPublishMethod(m *amqpMessage, args []byte) (bool, bool) {
 func basicReturnMethod(m *amqpMessage, args []byte) (bool, bool) {
 	code := binary.BigEndian.Uint16(args[0:2])
 	if code < 300 {
-		//not an error or exception ? not interesting
+		// not an error or exception ? not interesting
 		return true, false
 	}
 	replyText, nextOffset, err := getShortString(args, 3, uint32(args[2]))
@@ -707,7 +707,7 @@ func basicAckMethod(m *amqpMessage, args []byte) (bool, bool) {
 	return true, true
 }
 
-//this is a rabbitMQ specific method
+// this is a rabbitMQ specific method
 func basicNackMethod(m *amqpMessage, args []byte) (bool, bool) {
 	params := getBitParams(args[8])
 	m.method = "basic.nack"
@@ -761,14 +761,14 @@ func txRollbackMethod(m *amqpMessage, args []byte) (bool, bool) {
 	return true, true
 }
 
-//simple function used when server/client responds to a sync method with no new info
+// simple function used when server/client responds to a sync method with no new info
 func okMethod(m *amqpMessage, args []byte) (bool, bool) {
 	return true, true
 }
 
 // function to get a short string. It sends back an error if slice is too short
-//for declared length. if length == 0, the function sends back an empty string and
-//advances the offset. Otherwise, it returns the string and the new offset
+// for declared length. if length == 0, the function sends back an empty string and
+// advances the offset. Otherwise, it returns the string and the new offset
 func getShortString(data []byte, start uint32, length uint32) (short string, nextOffset uint32, err bool) {
 	if length == 0 {
 		return "", start, false
@@ -779,7 +779,7 @@ func getShortString(data []byte, start uint32, length uint32) (short string, nex
 	return string(data[start : start+length]), start + length, false
 }
 
-//function to extract bit information in various AMQP methods
+// function to extract bit information in various AMQP methods
 func getBitParams(bits byte) (ret [5]bool) {
 	if bits&16 == 16 {
 		ret[4] = true
diff --git a/packetbeat/protos/amqp/amqp_parser.go b/packetbeat/protos/amqp/amqp_parser.go
index 6ab15ec8159..a623219ca0b 100644
--- a/packetbeat/protos/amqp/amqp_parser.go
+++ b/packetbeat/protos/amqp/amqp_parser.go
@@ -42,10 +42,10 @@ func (amqp *amqpPlugin) amqpMessageParser(s *amqpStream) (ok bool, complete bool
 
 		f, err := readFrameHeader(s.data[s.parseOffset:])
 		if err {
-			//incorrect header
+			// incorrect header
 			return false, false
 		} else if f == nil {
-			//header not complete
+			// header not complete
 			return true, false
 		}
 
@@ -67,17 +67,14 @@ func (amqp *amqpPlugin) amqpMessageParser(s *amqpStream) (ok bool, complete bool
 		s.parseOffset += 8 + int(f.size)
 		if !ok {
 			return false, false
-		} else if complete {
+		}
+		if complete {
 			return true, true
 		}
 	}
 	return ok, complete
 }
 
-func (s *amqpStream) prepareForNewMessage() {
-	s.message = nil
-}
-
 func isProtocolHeader(data []byte) (isHeader bool, version string) {
 	if (string(data[:4]) == "AMQP") && data[4] == 0 {
 		return true, string(data[5:8])
@@ -85,7 +82,7 @@ func isProtocolHeader(data []byte) (isHeader bool, version string) {
 	return false, ""
 }
 
-//func to read a frame header and check if it is valid and complete
+// func to read a frame header and check if it is valid and complete
 func readFrameHeader(data []byte) (ret *amqpFrame, err bool) {
 	var frame amqpFrame
 	if len(data) < 8 {
@@ -103,7 +100,7 @@ func readFrameHeader(data []byte) (ret *amqpFrame, err bool) {
 	}
 	frame.Type = frameType(data[0])
 	if frame.size == 0 {
-		//frame content is nil with heartbeat frames
+		// frame content is nil with heartbeat frames
 		frame.content = nil
 	} else {
 		frame.content = data[7 : frame.size+7]
@@ -159,7 +156,7 @@ func (amqp *amqpPlugin) decodeHeaderFrame(s *amqpStream, buf []byte) bool {
 	s.message.bodySize = binary.BigEndian.Uint64(buf[4:12])
 	debugf("Received Header frame. A message of %d bytes is expected", s.message.bodySize)
 
-	if amqp.parseHeaders == true {
+	if amqp.parseHeaders {
 		err := getMessageProperties(s, buf[12:])
 		if err {
 			return false
@@ -180,7 +177,7 @@ func (s *amqpStream) decodeBodyFrame(buf []byte) (ok bool, complete bool) {
 
 	debugf("A body frame of %d bytes long has been transmitted",
 		len(buf))
-	//is the message complete ? If yes, let's publish it
+	// is the message complete ? If yes, let's publish it
 
 	complete = uint64(len(s.message.body)) >= s.message.bodySize
 	return true, complete
@@ -190,16 +187,16 @@ func hasProperty(prop, flag byte) bool {
 	return (prop & flag) == flag
 }
 
-//function to get message content-type and content-encoding
+// function to get message content-type and content-encoding
 func getMessageProperties(s *amqpStream, data []byte) bool {
 	m := s.message
 
-	//properties are coded in the two first bytes
+	// properties are coded in the two first bytes
 	prop1 := data[0]
 	prop2 := data[1]
 	var offset uint32 = 2
 
-	//while last bit set, we have another property flag field
+	// while last bit set, we have another property flag field
 	for lastbit := 1; data[lastbit]&1 == 1; {
 		lastbit += 2
 		offset += 2
@@ -238,9 +235,10 @@ func getMessageProperties(s *amqpStream, data []byte) bool {
 	}
 
 	if hasProperty(prop1, deliveryModeProp) {
-		if data[offset] == 1 {
+		switch data[offset] {
+		case 1:
 			m.fields["delivery-mode"] = "non-persistent"
-		} else if data[offset] == 2 {
+		case 2:
 			m.fields["delivery-mode"] = "persistent"
 		}
 		offset++
@@ -337,20 +335,20 @@ func (amqp *amqpPlugin) handleAmqp(m *amqpMessage, tcptuple *common.TCPTuple, di
 	m.direction = dir
 	m.cmdlineTuple = amqp.watcher.FindProcessesTupleTCP(tcptuple.IPPort())
 
-	if m.method == "basic.publish" {
+	switch {
+	case m.method == "basic.publish":
 		amqp.handlePublishing(m)
-	} else if m.method == "basic.deliver" || m.method == "basic.return" ||
-		m.method == "basic.get-ok" {
+	case m.method == "basic.deliver" || m.method == "basic.return" || m.method == "basic.get-ok":
 		amqp.handleDelivering(m)
-	} else if m.isRequest == true {
+	case m.isRequest:
 		amqp.handleAmqpRequest(m)
-	} else if m.isRequest == false {
+	default: // !m.isRequest
 		amqp.handleAmqpResponse(m)
 	}
 }
 
 func (amqp *amqpPlugin) mustHideCloseMethod(m *amqpMessage) bool {
-	return amqp.hideConnectionInformation == true &&
+	return amqp.hideConnectionInformation &&
 		(m.method == "connection.close" || m.method == "channel.close") &&
-		getReplyCode(m.fields) < uint16(300)
+		getReplyCode(m.fields) < 300
 }
diff --git a/packetbeat/protos/amqp/amqp_structs.go b/packetbeat/protos/amqp/amqp_structs.go
index 387e8df6fcb..ada8441c45a 100644
--- a/packetbeat/protos/amqp/amqp_structs.go
+++ b/packetbeat/protos/amqp/amqp_structs.go
@@ -30,12 +30,12 @@ const (
 	transactionTimeout   = 10 * 1e9
 )
 
-//layout used when a timestamp must be parsed
+// layout used when a timestamp must be parsed
 const (
 	amqpTimeLayout = "January _2 15:04:05 2006"
 )
 
-//Frame types and codes
+// Frame types and codes
 
 type frameType byte
 
@@ -50,7 +50,7 @@ const (
 	frameEndOctet byte = 206
 )
 
-//Codes for MethodMap
+// Codes for MethodMap
 type codeClass uint16
 
 const (
@@ -137,7 +137,7 @@ const (
 	txRollbackOk codeMethod = 31
 )
 
-//Message properties codes for byte prop1 in getMessageProperties
+// Message properties codes for byte prop1 in getMessageProperties
 const (
 	expirationProp      byte = 1
 	replyToProp         byte = 2
@@ -149,7 +149,7 @@ const (
 	contentTypeProp     byte = 128
 )
 
-//Message properties codes for byte prop2 in getMessageProperties
+// Message properties codes for byte prop2 in getMessageProperties
 
 const (
 	appIDProp     byte = 8
@@ -159,7 +159,7 @@ const (
 	messageIDProp byte = 128
 )
 
-//table types
+// table types
 const (
 	boolean        = 't'
 	shortShortInt  = 'b'
@@ -179,7 +179,7 @@ const (
 	timestamp      = 'T'
 	fieldTable     = 'F'
 	noField        = 'V'
-	byteArray      = 'x' //rabbitMQ specific field
+	byteArray      = 'x' // rabbitMQ specific field
 )
 
 type amqpPrivateData struct {
@@ -203,7 +203,7 @@ type amqpMessage struct {
 	direction      uint8
 	parseArguments bool
 
-	//mapstr containing all the options for the methods and header fields
+	// mapstr containing all the options for the methods and header fields
 	fields common.MapStr
 
 	body     []byte
diff --git a/packetbeat/protos/amqp/amqp_test.go b/packetbeat/protos/amqp/amqp_test.go
index 725de0f3d11..9b7f7dca35c 100644
--- a/packetbeat/protos/amqp/amqp_test.go
+++ b/packetbeat/protos/amqp/amqp_test.go
@@ -96,7 +96,7 @@ func TestAmqp_FrameSize(t *testing.T) {
 
 	_, amqp := amqpModForTests()
 
-	//incomplete frame
+	// incomplete frame
 	data, err := hex.DecodeString("0100000000000c000a001fffff000200")
 	assert.NoError(t, err)
 
@@ -118,7 +118,7 @@ func TestAmqp_PartialFrameSize(t *testing.T) {
 
 	_, amqp := amqpModForTests()
 
-	//incomplete frame
+	// incomplete frame
 	data, err := hex.DecodeString("414d515000060606010000000000")
 	assert.NoError(t, err)
 
@@ -275,7 +275,7 @@ func TestAmqp_ExchangeDeletion(t *testing.T) {
 	assert.Equal(t, false, m.fields["no-wait"])
 }
 
-//this method is exclusive to RabbitMQ
+// this method is exclusive to RabbitMQ
 func TestAmqp_ExchangeBind(t *testing.T) {
 	logp.TestingSetup(logp.WithSelectors("amqp", "amqpdetailed"))
 
@@ -308,7 +308,7 @@ func TestAmqp_ExchangeBind(t *testing.T) {
 	}
 }
 
-//this method is exclusive to RabbitMQ
+// this method is exclusive to RabbitMQ
 func TestAmqp_ExchangeUnbindTransaction(t *testing.T) {
 	logp.TestingSetup(logp.WithSelectors("amqp", "amqpdetailed"))
 
@@ -365,13 +365,13 @@ func TestAmqp_PublishMessage(t *testing.T) {
 	req := protos.Packet{Payload: data}
 	private := protos.ProtocolData(new(amqpPrivateData))
 
-	//method frame
+	// method frame
 	private = amqp.Parse(&req, tcptuple, 0, private)
 	req = protos.Packet{Payload: data2}
-	//header frame
+	// header frame
 	private = amqp.Parse(&req, tcptuple, 0, private)
 	req = protos.Packet{Payload: data3}
-	//body frame
+	// body frame
 	amqp.Parse(&req, tcptuple, 0, private)
 
 	trans := expectTransaction(t, results)
@@ -414,13 +414,13 @@ func TestAmqp_DeliverMessage(t *testing.T) {
 	req := protos.Packet{Payload: data}
 	private := protos.ProtocolData(new(amqpPrivateData))
 
-	//method frame
+	// method frame
 	private = amqp.Parse(&req, tcptuple, 0, private)
 	req = protos.Packet{Payload: data2}
-	//header frame
+	// header frame
 	private = amqp.Parse(&req, tcptuple, 0, private)
 	req = protos.Packet{Payload: data3}
-	//body frame
+	// body frame
 	amqp.Parse(&req, tcptuple, 0, private)
 
 	trans := expectTransaction(t, results)
@@ -467,7 +467,7 @@ func TestAmqp_MessagePropertiesFields(t *testing.T) {
 	assert.Equal(t, "el mensaje", m.fields["message-id"])
 	assert.Equal(t, "love message", m.fields["type"])
 	assert.Equal(t, "text/plain", m.fields["content-type"])
-	//assert.Equal(t, "September 15 15:31:44 2015", m.Fields["timestamp"])
+	// assert.Equal(t, "September 15 15:31:44 2015", m.Fields["timestamp"])
 	priority, ok := m.fields["priority"].(uint8)
 	if !ok {
 		t.Errorf("Field should be present")
@@ -576,7 +576,7 @@ func TestAmqp_RejectMessage(t *testing.T) {
 	req := protos.Packet{Payload: data}
 	private := protos.ProtocolData(new(amqpPrivateData))
 
-	//method frame
+	// method frame
 	amqp.Parse(&req, tcptuple, 0, private)
 
 	trans := expectTransaction(t, results)
@@ -668,8 +668,8 @@ func TestAmqp_MaxBodyLength(t *testing.T) {
 	req := protos.Packet{Payload: data}
 	private := protos.ProtocolData(new(amqpPrivateData))
 
-	//method frame
-	private = amqp.Parse(&req, tcptuple, 0, private)
+	// method frame
+	amqp.Parse(&req, tcptuple, 0, private)
 
 	trans := expectTransaction(t, results)
 
@@ -699,7 +699,7 @@ func TestAmqp_MaxBodyLength(t *testing.T) {
 	req = protos.Packet{Payload: data}
 	private = protos.ProtocolData(new(amqpPrivateData))
 
-	//method frame
+	// method frame
 	amqp.Parse(&req, tcptuple, 0, private)
 
 	trans = expectTransaction(t, results)
@@ -728,7 +728,7 @@ func TestAmqp_HideArguments(t *testing.T) {
 	amqp.parseHeaders = false
 	amqp.parseArguments = false
 
-	//parse args
+	// parse args
 	data, err := hex.DecodeString("0100010000004d0032000a00000a5465737448656164" +
 		"6572180000003704626f6f6c74010362697462050568656c6c6f530000001f4869206461" +
 		"726c696e6720c3aac3aac3aac3aac3aac3aac3aae697a5e69cacce")
@@ -736,7 +736,7 @@ func TestAmqp_HideArguments(t *testing.T) {
 	tcptuple := testTCPTuple()
 	req := protos.Packet{Payload: data}
 	private := protos.ProtocolData(new(amqpPrivateData))
-	private = amqp.Parse(&req, tcptuple, 0, private)
+	amqp.Parse(&req, tcptuple, 0, private)
 
 	trans := expectTransaction(t, results)
 	assert.Equal(t, "queue.declare", trans["method"])
@@ -753,7 +753,7 @@ func TestAmqp_HideArguments(t *testing.T) {
 		t.Errorf("Arguments field should not be present")
 	}
 
-	//parse headers
+	// parse headers
 	data, err = hex.DecodeString("01000100000013003c00280000000a546573744865616" +
 		"4657200ce02000100000026003c0000000000000000001a98800a746578742f706c61696" +
 		"e02060a656c206d656e73616a65ce0300010000001a54657374206865616465722066696" +
@@ -808,7 +808,7 @@ func TestAmqp_RecoverMethod(t *testing.T) {
 	assert.Equal(t, common.MapStr{"requeue": true}, trans["amqp"])
 }
 
-//this is a specific rabbitMQ method
+// this is a specific rabbitMQ method
 func TestAmqp_BasicNack(t *testing.T) {
 	logp.TestingSetup(logp.WithSelectors("amqp", "amqpdetailed"))
 
@@ -887,7 +887,7 @@ func TestAmqp_GetTable(t *testing.T) {
 	assert.Equal(t, true, m.fields["no-wait"])
 	assert.Equal(t, true, m.fields["auto-delete"])
 	assert.Equal(t, false, m.fields["exclusive"])
-	//assert.Equal(t, "September 15 11:25:29 2015", args["timestamp"])
+	// assert.Equal(t, "September 15 11:25:29 2015", args["timestamp"])
 	assert.Equal(t, "TestHeader", m.request)
 }
 
@@ -948,7 +948,7 @@ func TestAmqp_ArrayFields(t *testing.T) {
 
 	_, amqp := amqpModForTests()
 
-	//byte array, rabbitMQ specific field
+	// byte array, rabbitMQ specific field
 	data, err := hex.DecodeString("010001000000260028000a0000057465737431057" +
 		"46f706963020000000f05617272617978000000040a007dd2ce")
 	assert.NoError(t, err)
@@ -1025,7 +1025,7 @@ func TestAmqp_WrongTable(t *testing.T) {
 
 	_, amqp := amqpModForTests()
 
-	//declared table size too big
+	// declared table size too big
 	data, err := hex.DecodeString("010001000000890032000a00000a54657374486561646" +
 		"57218000000da0974696d657374616d70540000000055f7e409036269746205076465636" +
 		"96d616c440500ec49050568656c6c6f530000001f4869206461726c696e6720c3aac3aac" +
@@ -1048,7 +1048,7 @@ func TestAmqp_WrongTable(t *testing.T) {
 	}
 	assert.Equal(t, []string{"Failed to parse additional arguments"}, m.notes)
 
-	//table size ok, but total non-sense inside
+	// table size ok, but total non-sense inside
 	data, err = hex.DecodeString("010001000000890032000a00000a54657374486561646" +
 		"57218000000730974696d657374616d7054004400005521e409036269743705076400036" +
 		"96d616c447600ec49180568036c6c0b536400001f480a2064076e6c696e0520c3aac3aac" +
diff --git a/packetbeat/protos/amqp/config.go b/packetbeat/protos/amqp/config.go
index 2939530046e..4cbd5a5200a 100644
--- a/packetbeat/protos/amqp/config.go
+++ b/packetbeat/protos/amqp/config.go
@@ -30,14 +30,12 @@ type amqpConfig struct {
 	HideConnectionInformation bool `config:"hide_connection_information"`
 }
 
-var (
-	defaultConfig = amqpConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		ParseHeaders:              true,
-		ParseArguments:            true,
-		MaxBodyLength:             1000,
-		HideConnectionInformation: true,
-	}
-)
+var defaultConfig = amqpConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	ParseHeaders:              true,
+	ParseArguments:            true,
+	MaxBodyLength:             1000,
+	HideConnectionInformation: true,
+}
diff --git a/packetbeat/protos/cassandra/cassandra.go b/packetbeat/protos/cassandra/cassandra.go
index 7d3001a5159..5c7cbd003d1 100644
--- a/packetbeat/protos/cassandra/cassandra.go
+++ b/packetbeat/protos/cassandra/cassandra.go
@@ -50,9 +50,7 @@ type stream struct {
 	parser parser
 }
 
-var (
-	debugf = logp.MakeDebug("cassandra")
-)
+var debugf = logp.MakeDebug("cassandra")
 
 func init() {
 	protos.Register("cassandra", New)
@@ -202,11 +200,6 @@ func (cassandra *cassandra) ensureConnection(private protos.ProtocolData) *conne
 	return conn
 }
 
-func (conn *connection) dropStreams() {
-	conn.streams[0] = nil
-	conn.streams[1] = nil
-}
-
 func getConnection(private protos.ProtocolData) *connection {
 	if private == nil {
 		return nil
diff --git a/packetbeat/protos/cassandra/config.go b/packetbeat/protos/cassandra/config.go
index 0eafddcd1ee..8e93239bc6b 100644
--- a/packetbeat/protos/cassandra/config.go
+++ b/packetbeat/protos/cassandra/config.go
@@ -34,20 +34,18 @@ type cassandraConfig struct {
 	OPsIgnored            []gocql.FrameOp `config:"ignored_ops"`
 }
 
-var (
-	defaultConfig = cassandraConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-			SendRequest:        true,
-			SendResponse:       true,
-		},
-		SendRequestHeader:  true,
-		SendResponseHeader: true,
-	}
-)
+var defaultConfig = cassandraConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+		SendRequest:        true,
+		SendResponse:       true,
+	},
+	SendRequestHeader:  true,
+	SendResponseHeader: true,
+}
 
 func (c *cassandraConfig) Validate() error {
-	if !(c.Compressor == "" || c.Compressor == "snappy") {
+	if c.Compressor != "" && c.Compressor != "snappy" {
 		return fmt.Errorf("invalid compressor config: %s, only snappy supported", c.Compressor)
 	}
 	return nil
diff --git a/packetbeat/protos/cassandra/internal/gocql/array_decoder.go b/packetbeat/protos/cassandra/internal/gocql/array_decoder.go
index a224dc7d1b5..b64ecf8e146 100644
--- a/packetbeat/protos/cassandra/internal/gocql/array_decoder.go
+++ b/packetbeat/protos/cassandra/internal/gocql/array_decoder.go
@@ -26,10 +26,6 @@ type ByteArrayDecoder struct {
 	Data *[]byte
 }
 
-func readInt(p []byte) int32 {
-	return int32(p[0])<<24 | int32(p[1])<<16 | int32(p[2])<<8 | int32(p[3])
-}
-
 func (f ByteArrayDecoder) ReadByte() (byte, error) {
 	data := *f.Data
 	if len(data) < 1 {
@@ -167,7 +163,7 @@ func (f ByteArrayDecoder) ReadInet() (net.IP, int) {
 	size := data[0]
 	*f.Data = data[1:]
 
-	if !(size == 4 || size == 16) {
+	if size != 4 && size != 16 {
 		panic(fmt.Errorf("invalid IP size: %d", size))
 	}
 
diff --git a/packetbeat/protos/cassandra/internal/gocql/compressor.go b/packetbeat/protos/cassandra/internal/gocql/compressor.go
index cfbff208ade..fe6583c3a77 100644
--- a/packetbeat/protos/cassandra/internal/gocql/compressor.go
+++ b/packetbeat/protos/cassandra/internal/gocql/compressor.go
@@ -49,11 +49,11 @@ func (s SnappyCompressor) Decode(data []byte) ([]byte, error) {
 const LZ4 string = "lz4"
 
 type LZ4Compressor struct {
-	//TODO
+	// TODO
 }
 
 const Deflate string = "deflate"
 
 type DeflateCompressor struct {
-	//TODO
+	// TODO
 }
diff --git a/packetbeat/protos/cassandra/internal/gocql/decoder.go b/packetbeat/protos/cassandra/internal/gocql/decoder.go
index 734a940d8bd..f628aa65120 100644
--- a/packetbeat/protos/cassandra/internal/gocql/decoder.go
+++ b/packetbeat/protos/cassandra/internal/gocql/decoder.go
@@ -23,34 +23,19 @@ import (
 
 type Decoder interface {
 	ReadByte() (byte, error)
-
 	ReadInt() (n int)
-
 	ReadShort() (n uint16)
-
 	ReadLong() (n int64)
-
 	ReadString() (s string)
-
 	ReadLongString() (s string)
-
 	ReadUUID() *UUID
-
 	ReadStringList() []string
-
 	ReadBytesInternal() []byte
-
 	ReadBytes() []byte
-
 	ReadShortBytes() []byte
-
 	ReadInet() (net.IP, int)
-
 	ReadConsistency() Consistency
-
 	ReadStringMap() map[string]string
-
 	ReadBytesMap() map[string][]byte
-
 	ReadStringMultiMap() map[string][]string
 }
diff --git a/packetbeat/protos/cassandra/internal/gocql/frame.go b/packetbeat/protos/cassandra/internal/gocql/frame.go
index 25e7df5bac8..b8ae7eeac4e 100644
--- a/packetbeat/protos/cassandra/internal/gocql/frame.go
+++ b/packetbeat/protos/cassandra/internal/gocql/frame.go
@@ -182,18 +182,17 @@ func (f *Framer) ReadFrame() (data map[string]interface{}, err error) {
 
 	data = make(map[string]interface{})
 
-	//Only QUERY, PREPARE and EXECUTE queries support tracing
-	//If a response frame has the tracing flag set, its body contains
-	//a tracing ID. The tracing ID is a [uuid] and is the first thing in
-	//the frame body. The rest of the body will then be the usual body
-	//corresponding to the response opcode.
+	// Only QUERY, PREPARE and EXECUTE queries support tracing
+	// If a response frame has the tracing flag set, its body contains
+	// a tracing ID. The tracing ID is a [uuid] and is the first thing in
+	// the frame body. The rest of the body will then be the usual body
+	// corresponding to the response opcode.
 	if f.Header.Flags&flagTracing == flagTracing && (f.Header.Op&opQuery == opQuery || f.Header.Op&opExecute == opExecute || f.Header.Op&opPrepare == opPrepare) {
-
 		debugf("tracing enabled")
 
-		//seems no UUID to read, protocol incorrect?
-		//uid := decoder.ReadUUID()
-		//data["trace_id"] = uid.String()
+		// seems no UUID to read, protocol incorrect?
+		// uid := decoder.ReadUUID()
+		// data["trace_id"] = uid.String()
 	}
 
 	if f.Header.Flags&flagWarning == flagWarning {
@@ -211,7 +210,7 @@ func (f *Framer) ReadFrame() (data map[string]interface{}, err error) {
 	}
 
 	if f.Header.Flags&flagCompress == flagCompress {
-		//decompress data and switch to use bytearray decoder
+		// decompress data and switch to use bytearray decoder
 		if f.compres == nil {
 			logp.Err("hit compress flag, but compressor was not set")
 			panic(errors.New("hit compress flag, but compressor was not set"))
@@ -234,13 +233,13 @@ func (f *Framer) ReadFrame() (data map[string]interface{}, err error) {
 	// assumes that the frame body has been read into rbuf
 	switch f.Header.Op {
 
-	//below ops are requests
+	// below ops are requests
 	case opStartup, opAuthResponse, opOptions, opPrepare, opExecute, opBatch, opRegister:
-	//ignored
+	// ignored
 	case opQuery:
 		data = f.parseQueryFrame()
 
-	//below ops are responses
+	// below ops are responses
 	case opError:
 		data["error"] = f.parseErrorFrame()
 	case opResult:
@@ -259,7 +258,7 @@ func (f *Framer) ReadFrame() (data map[string]interface{}, err error) {
 		// the body should be empty
 
 	default:
-		//ignore
+		// ignore
 		debugf("unknow ops, not processed, %v", f.Header)
 
 	}
@@ -348,7 +347,7 @@ func (f *Framer) parseErrorFrame() (data map[string]interface{}) {
 
 	case errInvalid, errBootstrapping, errConfig, errCredentials, errOverloaded,
 		errProtocol, errServer, errSyntax, errTruncate, errUnauthorized:
-		//ignored
+		// ignored
 	default:
 		logp.Err("unknown error code: 0x%x", code)
 	}
@@ -375,8 +374,7 @@ func (f *Framer) parseResultMetadata(getPKinfo bool) map[string]interface{} {
 	meta["col_count"] = colCount
 
 	if getPKinfo {
-
-		//only for prepared result
+		// only for prepared result
 		if f.proto >= protoVersion4 {
 			pkeyCount := decoder.ReadInt()
 			pkeys := make([]int, pkeyCount)
@@ -450,7 +448,6 @@ func (f *Framer) parseResultPrepared() map[string]interface{} {
 	result := make(map[string]interface{})
 
 	uuid, err := UUIDFromBytes((f.decoder).ReadShortBytes())
-
 	if err != nil {
 		logp.Err("Error in parsing UUID")
 	}
diff --git a/packetbeat/protos/cassandra/internal/gocql/marshal.go b/packetbeat/protos/cassandra/internal/gocql/marshal.go
index 2061bb2f11e..3c55781cc81 100644
--- a/packetbeat/protos/cassandra/internal/gocql/marshal.go
+++ b/packetbeat/protos/cassandra/internal/gocql/marshal.go
@@ -349,8 +349,8 @@ const (
 	errUnprepared      ErrType = 0x2500
 )
 
-func (this ErrType) String() string {
-	switch this {
+func (e ErrType) String() string {
+	switch e {
 	case errUnavailable:
 		return "errUnavailable"
 	case errWriteTimeout:
@@ -680,7 +680,7 @@ func (u UUID) Bytes() []byte {
 // String returns the UUID in it's canonical form, a 32 digit hexadecimal
 // number in the form of xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.
 func (u UUID) String() string {
-	var offsets = [...]int{0, 2, 4, 6, 9, 11, 14, 16, 19, 21, 24, 26, 28, 30, 32, 34}
+	offsets := [...]int{0, 2, 4, 6, 9, 11, 14, 16, 19, 21, 24, 26, 28, 30, 32, 34}
 	const hexString = "0123456789abcdef"
 	r := make([]byte, 36)
 	for i, b := range u {
diff --git a/packetbeat/protos/cassandra/internal/gocql/stream_decoder.go b/packetbeat/protos/cassandra/internal/gocql/stream_decoder.go
index ae107a95e9e..f39cde2d11e 100644
--- a/packetbeat/protos/cassandra/internal/gocql/stream_decoder.go
+++ b/packetbeat/protos/cassandra/internal/gocql/stream_decoder.go
@@ -149,7 +149,7 @@ func (f StreamDecoder) ReadInet() (net.IP, int) {
 		panic(err)
 	}
 
-	if !(size == 4 || size == 16) {
+	if size != 4 && size != 16 {
 		panic(fmt.Errorf("invalid IP size: %d", size))
 	}
 
diff --git a/packetbeat/protos/cassandra/parser.go b/packetbeat/protos/cassandra/parser.go
index f699187b03f..65ff347a1ea 100644
--- a/packetbeat/protos/cassandra/parser.go
+++ b/packetbeat/protos/cassandra/parser.go
@@ -44,14 +44,7 @@ type parserConfig struct {
 
 // check whether this ops is enabled or not
 func (p *parser) CheckFrameOpsIgnored() bool {
-	if p.config.ignoredOps != nil && len(p.config.ignoredOps) > 0 {
-		//default map value is false
-		v := p.config.ignoredOps[p.framer.Header.Op]
-		if v {
-			return true
-		}
-	}
-	return false
+	return p.config.ignoredOps[p.framer.Header.Op]
 }
 
 type message struct {
@@ -69,8 +62,6 @@ type message struct {
 	// list element use by 'transactions' for correlation
 	next *message
 
-	transactionTimeout time.Duration
-
 	results transactions
 }
 
@@ -91,7 +82,6 @@ func (p *parser) init(
 	}
 
 	isDebug = logp.IsDebug("cassandra")
-
 }
 
 func (p *parser) append(data []byte) error {
@@ -153,7 +143,7 @@ func (p *parser) parserBody() (bool, error) {
 		return true, nil
 	}
 
-	//let's wait for enough buf
+	// let's wait for enough buf
 	debugf("bodyLength: %d", bdyLen)
 	if !p.buf.Avail(bdyLen) {
 		if isDebug {
@@ -162,7 +152,7 @@ func (p *parser) parserBody() (bool, error) {
 		return false, nil
 	}
 
-	//check if the ops already ignored
+	// check if the ops already ignored
 	if p.message.ignored {
 		if isDebug {
 			debugf("message marked to be ignored, let's do this")
@@ -232,7 +222,7 @@ func (p *parser) parse() (*message, error) {
 		}
 	}
 
-	//check if the ops need to be ignored
+	// check if the ops need to be ignored
 	if p.CheckFrameOpsIgnored() {
 		// as we already ignore the content, we now mark the result is ignored
 		p.message.ignored = true
@@ -248,7 +238,7 @@ func (p *parser) parse() (*message, error) {
 		return nil, err
 	}
 
-	//ignore and wait for more data
+	// ignore and wait for more data
 	if !finished {
 		return nil, nil
 	}
diff --git a/packetbeat/protos/cassandra/pub.go b/packetbeat/protos/cassandra/pub.go
index 3b90c53feae..82effab92d3 100644
--- a/packetbeat/protos/cassandra/pub.go
+++ b/packetbeat/protos/cassandra/pub.go
@@ -33,7 +33,6 @@ type transPub struct {
 	sendResponse       bool
 	sendRequestHeader  bool
 	sendResponseHeader bool
-	ignoredOps         string
 
 	results protos.Reporter
 }
@@ -82,7 +81,7 @@ func (pub *transPub) createEvent(requ, resp *message) beat.Event {
 	cassandra := common.MapStr{}
 	status := common.OK_STATUS
 
-	//requ can be null, if the message is a PUSHed message
+	// requ can be null, if the message is a PUSHed message
 	if requ != nil {
 		pbf.Source.Bytes = int64(requ.Size)
 		pbf.Event.Start = requ.Ts
@@ -101,7 +100,7 @@ func (pub *transPub) createEvent(requ, resp *message) beat.Event {
 			}
 		}
 	} else {
-		//dealing with PUSH message
+		// dealing with PUSH message
 		cassandra["no_request"] = true
 	}
 
diff --git a/packetbeat/protos/cassandra/trans.go b/packetbeat/protos/cassandra/trans.go
index 9b055d22c88..d7a9ae60d5f 100644
--- a/packetbeat/protos/cassandra/trans.go
+++ b/packetbeat/protos/cassandra/trans.go
@@ -132,7 +132,6 @@ func (trans *transactions) onResponse(
 func (trans *transactions) tryMergeRequests(
 	prev, msg *message,
 ) (merged bool, err error) {
-
 	msg.isComplete = true
 	return false, nil
 }
@@ -150,7 +149,7 @@ func (trans *transactions) correlate() error {
 	if requests.empty() {
 		for !responses.empty() {
 
-			//if the response is EVENT, which pushed from server, we can accept that
+			// if the response is EVENT, which pushed from server, we can accept that
 			resp := responses.first()
 			if !resp.isComplete {
 				break
diff --git a/packetbeat/protos/dhcpv4/config.go b/packetbeat/protos/dhcpv4/config.go
index 4121ee66ba7..7245e3c641b 100644
--- a/packetbeat/protos/dhcpv4/config.go
+++ b/packetbeat/protos/dhcpv4/config.go
@@ -25,10 +25,8 @@ type dhcpv4Config struct {
 	config.ProtocolCommon `config:",inline"`
 }
 
-var (
-	defaultConfig = dhcpv4Config{
-		ProtocolCommon: config.ProtocolCommon{
-			Ports: []int{67, 68},
-		},
-	}
-)
+var defaultConfig = dhcpv4Config{
+	ProtocolCommon: config.ProtocolCommon{
+		Ports: []int{67, 68},
+	},
+}
diff --git a/packetbeat/protos/dns/config.go b/packetbeat/protos/dns/config.go
index c98d52f8257..c1044cf2f7c 100644
--- a/packetbeat/protos/dns/config.go
+++ b/packetbeat/protos/dns/config.go
@@ -28,10 +28,8 @@ type dnsConfig struct {
 	IncludeAdditionals    bool `config:"include_additionals"`
 }
 
-var (
-	defaultConfig = dnsConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-	}
-)
+var defaultConfig = dnsConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+}
diff --git a/packetbeat/protos/dns/dns.go b/packetbeat/protos/dns/dns.go
index 125d6112bae..04be88a36b1 100644
--- a/packetbeat/protos/dns/dns.go
+++ b/packetbeat/protos/dns/dns.go
@@ -59,18 +59,10 @@ type dnsPlugin struct {
 	watcher procs.ProcessesWatcher
 }
 
-var (
-	debugf = logp.MakeDebug("dns")
-)
+var debugf = logp.MakeDebug("dns")
 
 const maxDNSTupleRawSize = 16 + 16 + 2 + 2 + 4 + 1
 
-// Constants used to associate the DNS QR flag with a meaningful value.
-const (
-	query    = false
-	response = true
-)
-
 // Transport protocol.
 type transport uint8
 
@@ -203,13 +195,12 @@ func (dns *dnsPlugin) getTransaction(k hashableDNSTuple) *dnsTransaction {
 }
 
 type dnsTransaction struct {
-	ts           time.Time // Time when the request was received.
-	tuple        dnsTuple  // Key used to track this transaction in the transactionsMap.
-	responseTime int32     // Elapsed time in milliseconds between the request and response.
-	src          common.Endpoint
-	dst          common.Endpoint
-	transport    transport
-	notes        []string
+	ts        time.Time // Time when the request was received.
+	tuple     dnsTuple  // Key used to track this transaction in the transactionsMap.
+	src       common.Endpoint
+	dst       common.Endpoint
+	transport transport
+	notes     []string
 
 	request  *dnsMessage
 	response *dnsMessage
diff --git a/packetbeat/protos/dns/dns_tcp.go b/packetbeat/protos/dns/dns_tcp.go
index bbf7e736926..8addcdd6896 100644
--- a/packetbeat/protos/dns/dns_tcp.go
+++ b/packetbeat/protos/dns/dns_tcp.go
@@ -107,7 +107,6 @@ func (dns *dnsPlugin) doParse(conn *dnsConnectionData, pkt *protos.Packet, tcpTu
 		}
 	}
 	decodedData, err := stream.handleTCPRawData()
-
 	if err != nil {
 
 		if err == incompleteMsg {
@@ -259,8 +258,8 @@ func (dns *dnsPlugin) publishResponseError(conn *dnsConnectionData, err error) {
 	trans.notes = append(trans.notes, errDNS.responseError())
 
 	// Should we publish the length (bytes_out) of the failed Response?
-	//streamReverse.message.Length = len(streamReverse.rawData)
-	//trans.Response = streamReverse.message
+	// streamReverse.message.Length = len(streamReverse.rawData)
+	// trans.Response = streamReverse.message
 
 	dns.publishTransaction(trans)
 	dns.deleteTransaction(hashDNSTupleOrigin)
@@ -296,7 +295,6 @@ func (stream *dnsStream) handleTCPRawData() (*mkdns.Msg, error) {
 	}
 
 	decodedData, err := decodeDNSData(transportTCP, rawData[:stream.parseOffset])
-
 	if err != nil {
 		return nil, err
 	}
diff --git a/packetbeat/protos/dns/dns_test.go b/packetbeat/protos/dns/dns_test.go
index 9427ebeaecf..1ba03b2bd61 100644
--- a/packetbeat/protos/dns/dns_test.go
+++ b/packetbeat/protos/dns/dns_test.go
@@ -316,8 +316,10 @@ func TestRRsToMapStrsWithOPTRecord(t *testing.T) {
 	o.Hdr.Rrtype = mkdns.TypeOPT
 
 	r := new(mkdns.MX)
-	r.Hdr = mkdns.RR_Header{Name: "miek.nl", Rrtype: mkdns.TypeMX,
-		Class: mkdns.ClassINET, Ttl: 3600}
+	r.Hdr = mkdns.RR_Header{
+		Name: "miek.nl", Rrtype: mkdns.TypeMX,
+		Class: mkdns.ClassINET, Ttl: 3600,
+	}
 	r.Preference = 10
 	r.Mx = "mx.miek.nl"
 
diff --git a/packetbeat/protos/dns/dns_udp_test.go b/packetbeat/protos/dns/dns_udp_test.go
index 3711fb50e00..62713502e0a 100644
--- a/packetbeat/protos/dns/dns_udp_test.go
+++ b/packetbeat/protos/dns/dns_udp_test.go
@@ -155,10 +155,12 @@ var (
 		qSubdomain: "131.252.30",
 		qTLD:       "in-addr.arpa",
 		answers:    []string{"github.com"},
-		authorities: []string{"a.root-servers.net", "b.root-servers.net", "c.root-servers.net",
+		authorities: []string{
+			"a.root-servers.net", "b.root-servers.net", "c.root-servers.net",
 			"d.root-servers.net", "e.root-servers.net", "f.root-servers.net", "g.root-servers.net",
 			"h.root-servers.net", "i.root-servers.net", "j.root-servers.net", "k.root-servers.net",
-			"l.root-servers.net", "m.root-servers.net"},
+			"l.root-servers.net", "m.root-servers.net",
+		},
 		request: []byte{
 			0x01, 0x58, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x31, 0x33, 0x31,
 			0x03, 0x32, 0x35, 0x32, 0x02, 0x33, 0x30, 0x03, 0x31, 0x39, 0x32, 0x07, 0x69, 0x6e, 0x2d, 0x61,
diff --git a/packetbeat/protos/http/config.go b/packetbeat/protos/http/config.go
index 86f59fb36b1..45878934b0c 100644
--- a/packetbeat/protos/http/config.go
+++ b/packetbeat/protos/http/config.go
@@ -39,12 +39,10 @@ type httpConfig struct {
 	RedactHeaders          []string `config:"redact_headers"`
 }
 
-var (
-	defaultConfig = httpConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		MaxMessageSize: tcp.TCPMaxDataInStream,
-		DecodeBody:     true,
-	}
-)
+var defaultConfig = httpConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	MaxMessageSize: tcp.TCPMaxDataInStream,
+	DecodeBody:     true,
+}
diff --git a/packetbeat/protos/http/http.go b/packetbeat/protos/http/http.go
index e86cb665587..9cc436f84f0 100644
--- a/packetbeat/protos/http/http.go
+++ b/packetbeat/protos/http/http.go
@@ -39,8 +39,10 @@ import (
 	"github.com/elastic/beats/v7/packetbeat/protos"
 )
 
-var debugf = logp.MakeDebug("http")
-var detailedf = logp.MakeDebug("httpdetailed")
+var (
+	debugf    = logp.MakeDebug("http")
+	detailedf = logp.MakeDebug("httpdetailed")
+)
 
 type parserState uint8
 
@@ -300,7 +302,6 @@ func (http *httpPlugin) doParse(
 	tcptuple *common.TCPTuple,
 	dir uint8,
 ) *httpConnectionData {
-
 	if isDetailed {
 		detailedf("Payload received: [%s]", pkt.Payload)
 	}
@@ -368,8 +369,8 @@ func newStream(pkt *protos.Packet, tcptuple *common.TCPTuple) *stream {
 
 // ReceivedFin will be called when TCP transaction is terminating.
 func (http *httpPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
-	private protos.ProtocolData) protos.ProtocolData {
-
+	private protos.ProtocolData,
+) protos.ProtocolData {
 	debugf("Received FIN")
 	conn := getHTTPConnection(private)
 	if conn == nil {
@@ -396,8 +397,8 @@ func (http *httpPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
 // GapInStream is called when a gap of nbytes bytes is found in the stream (due
 // to packet loss).
 func (http *httpPlugin) GapInStream(tcptuple *common.TCPTuple, dir uint8,
-	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool) {
-
+	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool,
+) {
 	defer logp.Recover("GapInStream(http) exception")
 
 	conn := getHTTPConnection(private)
@@ -436,7 +437,6 @@ func (http *httpPlugin) handleHTTP(
 	tcptuple *common.TCPTuple,
 	dir uint8,
 ) {
-
 	m.tcpTuple = *tcptuple
 	m.direction = dir
 	m.cmdlineTuple = http.watcher.FindProcessesTupleTCP(tcptuple.IPPort())
@@ -488,7 +488,6 @@ func (http *httpPlugin) flushRequests(conn *httpConnectionData) {
 }
 
 func (http *httpPlugin) correlate(conn *httpConnectionData) {
-
 	// drop responses with missing requests
 	if conn.requests.empty() {
 		http.flushResponses(conn)
@@ -724,8 +723,7 @@ func splitCookiesHeader(headerVal string) map[string]string {
 	for _, cval := range cstring {
 		cookie := strings.SplitN(cval, "=", 2)
 		if len(cookie) == 2 {
-			cookies[strings.ToLower(strings.TrimSpace(cookie[0]))] =
-				parseCookieValue(strings.TrimSpace(cookie[1]))
+			cookies[strings.ToLower(strings.TrimSpace(cookie[0]))] = parseCookieValue(strings.TrimSpace(cookie[1]))
 		}
 	}
 
@@ -928,10 +926,6 @@ func (ml *messageList) pop() *message {
 	return msg
 }
 
-func (ml *messageList) last() *message {
-	return ml.tail
-}
-
 func extractBasicAuthUser(headers map[string]common.NetString) string {
 	const prefix = "Basic "
 
diff --git a/packetbeat/protos/http/http_parser.go b/packetbeat/protos/http/http_parser.go
index be4343ea120..a903460f772 100644
--- a/packetbeat/protos/http/http_parser.go
+++ b/packetbeat/protos/http/http_parser.go
@@ -45,7 +45,7 @@ type message struct {
 	cmdlineTuple *common.ProcessTuple
 	direction    uint8
 
-	//Request Info
+	// Request Info
 	requestURI   common.NetString
 	method       common.NetString
 	statusCode   uint16
@@ -187,7 +187,7 @@ func (*parser) parseHTTPLine(s *stream, m *message) (cont, ok, complete bool) {
 		return false, false, false
 	}
 	if bytes.Equal(fline[0:5], constHTTPVersion) {
-		//RESPONSE
+		// RESPONSE
 		m.isRequest = false
 		version = fline[5:8]
 		m.statusCode, m.statusPhrase, err = parseResponseStatus(fline[9:])
@@ -289,7 +289,7 @@ func (parser *parser) parseHeaders(s *stream, m *message) (cont, ok, complete bo
 		s.parseOffset = 0
 
 		if !m.isRequest && ((100 <= m.statusCode && m.statusCode < 200) || m.statusCode == 204 || m.statusCode == 304) {
-			//response with a 1xx, 204 , or 304 status  code is always terminated
+			// response with a 1xx, 204 , or 304 status  code is always terminated
 			// by the first empty line after the  header fields
 			if isDebug {
 				debugf("Terminate response, status code %d", m.statusCode)
diff --git a/packetbeat/protos/http/http_test.go b/packetbeat/protos/http/http_test.go
index 0fa9077a5ed..4179a047d56 100644
--- a/packetbeat/protos/http/http_test.go
+++ b/packetbeat/protos/http/http_test.go
@@ -56,10 +56,6 @@ func (e *eventStore) publish(event beat.Event) {
 	e.events = append(e.events, event)
 }
 
-func (e *eventStore) empty() bool {
-	return len(e.events) == 0
-}
-
 func newTestParser(http *httpPlugin, payloads ...string) *testParser {
 	if http == nil {
 		http = httpModForTests(nil)
@@ -538,7 +534,7 @@ func TestHttpParser_RequestResponseBody(t *testing.T) {
 
 	tp.stream.PrepareForNewMessage()
 	tp.stream.message = &message{ts: time.Now()}
-	msg, ok, complete = tp.parse()
+	_, ok, complete = tp.parse()
 	assert.True(t, ok)
 	assert.True(t, complete)
 }
@@ -646,17 +642,23 @@ func TestEatBodyChunked(t *testing.T) {
 	st.data = append(st.data, msgs[1]...)
 	cont, ok, complete = parser.parseBodyChunkedStart(st, msg)
 	assert.True(t, cont)
+	assert.True(t, ok)
+	assert.False(t, complete)
 	assert.Equal(t, 3, msg.chunkedLength)
 	assert.Equal(t, 0, len(msg.body))
 	assert.Equal(t, stateBodyChunked, st.parseState)
 
 	cont, ok, complete = parser.parseBodyChunked(st, msg)
 	assert.True(t, cont)
+	assert.True(t, ok)
+	assert.False(t, complete)
 	assert.Equal(t, stateBodyChunkedStart, st.parseState)
 	assert.Equal(t, 3, msg.contentLength)
 
 	cont, ok, complete = parser.parseBodyChunkedStart(st, msg)
 	assert.True(t, cont)
+	assert.True(t, ok)
+	assert.False(t, complete)
 	assert.Equal(t, 3, msg.chunkedLength)
 	assert.Equal(t, 3, msg.contentLength)
 	assert.Equal(t, stateBodyChunked, st.parseState)
@@ -672,6 +674,8 @@ func TestEatBodyChunked(t *testing.T) {
 	st.data = append(st.data, msgs[2]...)
 	cont, ok, complete = parser.parseBodyChunked(st, msg)
 	assert.True(t, cont)
+	assert.True(t, ok)
+	assert.False(t, complete)
 	assert.Equal(t, 6, msg.contentLength)
 	assert.Equal(t, stateBodyChunkedStart, st.parseState)
 
@@ -729,7 +733,6 @@ func TestEatBodyChunkedWaitCRLF(t *testing.T) {
 	ok, complete = parser.parseBodyChunkedWaitFinalCRLF(st, msg)
 	if ok != true || complete != false {
 		t.Error("Wrong return values", ok, complete)
-
 	}
 	st.data = append(st.data, msgs[1]...)
 
@@ -817,13 +820,12 @@ func TestHttpParser_censorPasswordPOST(t *testing.T) {
 	http.parserConfig.sendHeaders = true
 	http.parserConfig.sendAllHeaders = true
 
-	data1 :=
-		"POST /users/login HTTP/1.1\r\n" +
-			"HOST: www.example.com\r\n" +
-			"Content-Type: application/x-www-form-urlencoded\r\n" +
-			"Content-Length: 28\r\n" +
-			"\r\n" +
-			"username=ME&password=secret\r\n"
+	data1 := "POST /users/login HTTP/1.1\r\n" +
+		"HOST: www.example.com\r\n" +
+		"Content-Type: application/x-www-form-urlencoded\r\n" +
+		"Content-Length: 28\r\n" +
+		"\r\n" +
+		"username=ME&password=secret\r\n"
 	tp := newTestParser(http, data1)
 
 	msg, ok, complete := tp.parse()
@@ -1511,7 +1513,8 @@ func TestHTTP_Encodings(t *testing.T) {
 	gzipDeflateBody := string([]byte{
 		0x1f, 0x8b, 0x08, 0x00, 0x65, 0xdb, 0x6a, 0x5b, 0x00, 0x03, 0x3b, 0x7d,
 		0xe2, 0xbc, 0xe7, 0x13, 0x26, 0x06, 0x00, 0x95, 0xfa, 0x49, 0xbf, 0x07,
-		0x00, 0x00, 0x00})
+		0x00, 0x00, 0x00,
+	})
 
 	var store eventStore
 	http := httpModForTests(&store)
diff --git a/packetbeat/protos/icmp/config.go b/packetbeat/protos/icmp/config.go
index cb3ee28d7f9..4fcdb6667e5 100644
--- a/packetbeat/protos/icmp/config.go
+++ b/packetbeat/protos/icmp/config.go
@@ -29,8 +29,6 @@ type icmpConfig struct {
 	TransactionTimeout time.Duration `config:"transaction_timeout"`
 }
 
-var (
-	defaultConfig = icmpConfig{
-		TransactionTimeout: protos.DefaultTransactionExpiration,
-	}
-)
+var defaultConfig = icmpConfig{
+	TransactionTimeout: protos.DefaultTransactionExpiration,
+}
diff --git a/packetbeat/protos/icmp/icmp.go b/packetbeat/protos/icmp/icmp.go
index 521bb019ce6..c204b819adb 100644
--- a/packetbeat/protos/icmp/icmp.go
+++ b/packetbeat/protos/icmp/icmp.go
@@ -102,7 +102,7 @@ func (icmp *icmpPlugin) init(results protos.Reporter, watcher procs.ProcessesWat
 	}
 	logp.Debug("icmp", "Local IP addresses: %s", icmp.localIps)
 
-	var removalListener = func(k common.Key, v common.Value) {
+	removalListener := func(k common.Key, v common.Value) {
 		icmp.expireTransaction(k.(hashableIcmpTuple), v.(*icmpTransaction))
 	}
 
@@ -145,7 +145,7 @@ func (icmp *icmpPlugin) ProcessICMPv4(
 		ts:     pkt.Ts,
 		Type:   typ,
 		code:   code,
-		length: len(icmp4.BaseLayer.Payload),
+		length: len(icmp4.Payload),
 	}
 
 	if isRequest(tuple, msg) {
@@ -180,7 +180,7 @@ func (icmp *icmpPlugin) ProcessICMPv6(
 		ts:     pkt.Ts,
 		Type:   typ,
 		code:   code,
-		length: len(icmp6.BaseLayer.Payload),
+		length: len(icmp6.Payload),
 	}
 
 	if isRequest(tuple, msg) {
@@ -257,14 +257,6 @@ func (icmp *icmpPlugin) isLocalIP(ip net.IP) bool {
 	return false
 }
 
-func (icmp *icmpPlugin) getTransaction(k hashableIcmpTuple) *icmpTransaction {
-	v := icmp.transactions.Get(k)
-	if v != nil {
-		return v.(*icmpTransaction)
-	}
-	return nil
-}
-
 func (icmp *icmpPlugin) deleteTransaction(k hashableIcmpTuple) *icmpTransaction {
 	v := icmp.transactions.Delete(k)
 	if v != nil {
diff --git a/packetbeat/protos/icmp/tuple_test.go b/packetbeat/protos/icmp/tuple_test.go
index 7c9112decb1..b8d09e6753f 100644
--- a/packetbeat/protos/icmp/tuple_test.go
+++ b/packetbeat/protos/icmp/tuple_test.go
@@ -79,7 +79,8 @@ func TestIcmpTupleHashable(t *testing.T) {
 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 192, 168, 0, 2,
 		1, 0,
 		0, 1,
-		4}
+		4,
+	}
 
 	assert.Equal(t, expectedHashable, actualHashable)
 }
diff --git a/packetbeat/protos/memcache/binary.go b/packetbeat/protos/memcache/binary.go
index f9db915ce8a..ee831055317 100644
--- a/packetbeat/protos/memcache/binary.go
+++ b/packetbeat/protos/memcache/binary.go
@@ -28,8 +28,6 @@ import (
 	"github.com/elastic/beats/v7/libbeat/common/streambuf"
 )
 
-type memcacheMagic uint8
-
 const (
 	memcacheMagicRequest  = 0x80
 	memcacheMagicResponse = 0x81
@@ -56,10 +54,11 @@ var binStatsValue = argDef{
 	serialize: serializeStats,
 }
 
-var extraValue = makeValueExtra("value")
-var extraDelta = makeValueExtra("delta")
-var extraInitial = makeValue2Extra("initial")
-var extraVerbosity = make32ValueExtra("verbosity")
+var (
+	extraDelta     = makeValueExtra("delta")
+	extraInitial   = makeValue2Extra("initial")
+	extraVerbosity = make32ValueExtra("verbosity")
+)
 
 func init() {
 	// define all memcache opcode commands:
diff --git a/packetbeat/protos/memcache/config.go b/packetbeat/protos/memcache/config.go
index e558c84153d..dfe01e86e3b 100644
--- a/packetbeat/protos/memcache/config.go
+++ b/packetbeat/protos/memcache/config.go
@@ -32,11 +32,9 @@ type memcacheConfig struct {
 	ParseUnknown          bool
 }
 
-var (
-	defaultConfig = memcacheConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		UDPTransactionTimeout: protos.DefaultTransactionExpiration,
-	}
-)
+var defaultConfig = memcacheConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	UDPTransactionTimeout: protos.DefaultTransactionExpiration,
+}
diff --git a/packetbeat/protos/memcache/errors.go b/packetbeat/protos/memcache/errors.go
index 3b6b5b9ae45..282812a3492 100644
--- a/packetbeat/protos/memcache/errors.go
+++ b/packetbeat/protos/memcache/errors.go
@@ -23,9 +23,7 @@ import (
 	"errors"
 )
 
-var (
-	errNotImplemented = errors.New("not implemented")
-)
+var errNotImplemented = errors.New("not implemented")
 
 // memcache text parser errors
 var (
diff --git a/packetbeat/protos/memcache/parse.go b/packetbeat/protos/memcache/parse.go
index 2fe774c19e5..01ce9a05acb 100644
--- a/packetbeat/protos/memcache/parse.go
+++ b/packetbeat/protos/memcache/parse.go
@@ -25,11 +25,6 @@ import (
 	"github.com/elastic/beats/v7/libbeat/common/streambuf"
 )
 
-const (
-	codeSpace byte = ' '
-	codeTab        = '\t'
-)
-
 type parserConfig struct {
 	maxValues        int
 	maxBytesPerValue int
diff --git a/packetbeat/protos/memcache/parse_test.go b/packetbeat/protos/memcache/parse_test.go
index 95fdac5bad3..e1ac77160f5 100644
--- a/packetbeat/protos/memcache/parse_test.go
+++ b/packetbeat/protos/memcache/parse_test.go
@@ -56,8 +56,10 @@ type binValueWriter interface {
 	WriteNetUint64At(uint64, int) error
 }
 
-type extraFn func(binValueWriter) int
-type valueFn func(*streambuf.Buffer, int) int
+type (
+	extraFn func(binValueWriter) int
+	valueFn func(*streambuf.Buffer, int) int
+)
 
 type offsetBinWriter struct {
 	w      binValueWriter
diff --git a/packetbeat/protos/memcache/plugin_tcp.go b/packetbeat/protos/memcache/plugin_tcp.go
index 830a0cd64a5..c16abb3c712 100644
--- a/packetbeat/protos/memcache/plugin_tcp.go
+++ b/packetbeat/protos/memcache/plugin_tcp.go
@@ -60,8 +60,6 @@ type messageList struct {
 	tail *message
 }
 
-const defaultTCPTransDuration uint = 200
-
 func ensureMemcacheConnection(private protos.ProtocolData) *tcpConnectionData {
 	if private == nil {
 		return &tcpConnectionData{}
diff --git a/packetbeat/protos/memcache/text.go b/packetbeat/protos/memcache/text.go
index 72b36442c9a..86baa8d0627 100644
--- a/packetbeat/protos/memcache/text.go
+++ b/packetbeat/protos/memcache/text.go
@@ -109,12 +109,14 @@ var argStat = argDef{
 	serialize: serializeStats,
 }
 
-var argDelta = makeValueArg("delta")
-var argSleepUs = makeValueArg("sleep_us")
-var argValue = makeValueArg("value")
-var argVerbosity = makeValueArg("verbosity")
-var argSourceClass = makeIValueArg("source_class")
-var argDestClass = makeIValue2Arg("dest_class")
+var (
+	argDelta       = makeValueArg("delta")
+	argSleepUs     = makeValueArg("sleep_us")
+	argValue       = makeValueArg("value")
+	argVerbosity   = makeValueArg("verbosity")
+	argSourceClass = makeIValueArg("source_class")
+	argDestClass   = makeIValue2Arg("dest_class")
+)
 
 var argNoReply = argDef{
 	parse: func(parser *parser, hdr, buf *streambuf.Buffer) error {
@@ -297,8 +299,10 @@ func makeDefTextDataMessage(
 	}
 }
 
-var defTextDataRequest = makeDefTextDataMessage(true)
-var defTextDataResponse = makeDefTextDataMessage(false)
+var (
+	defTextDataRequest  = makeDefTextDataMessage(true)
+	defTextDataResponse = makeDefTextDataMessage(false)
+)
 
 func loadCommand(name string, code commandCode) textCommandType {
 	return defTextMessage(name, memcacheLoadMsg, code, argMultiKeys)
@@ -403,13 +407,6 @@ func makeValueArg(name string) argDef {
 	}
 }
 
-func makeValue2Arg(name string) argDef {
-	return argDef{
-		parse:     textUint64Arg(setValue2),
-		serialize: serializeValue2(name),
-	}
-}
-
 func makeIValueArg(name string) argDef {
 	return argDef{
 		parse: func(parser *parser, hdr, buf *streambuf.Buffer) error {
@@ -592,7 +589,7 @@ func parseNoReplyArg(buf *streambuf.Buffer) (bool, error) {
 		return false, textArgError(err)
 	}
 
-	var noreplyArg = []byte("noreply")
+	noreplyArg := []byte("noreply")
 	noreply := bytes.HasPrefix(buf.Bytes(), noreplyArg)
 	if !noreply {
 		return false, errExpectedNoReply
diff --git a/packetbeat/protos/mongodb/config.go b/packetbeat/protos/mongodb/config.go
index e7e2143b647..c90aeb67290 100644
--- a/packetbeat/protos/mongodb/config.go
+++ b/packetbeat/protos/mongodb/config.go
@@ -28,12 +28,10 @@ type mongodbConfig struct {
 	MaxDocs               int `config:"max_docs"`
 }
 
-var (
-	defaultConfig = mongodbConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		MaxDocLength: 5000,
-		MaxDocs:      10,
-	}
-)
+var defaultConfig = mongodbConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	MaxDocLength: 5000,
+	MaxDocs:      10,
+}
diff --git a/packetbeat/protos/mongodb/mongodb.go b/packetbeat/protos/mongodb/mongodb.go
index b05ebce9150..0fcc5464b45 100644
--- a/packetbeat/protos/mongodb/mongodb.go
+++ b/packetbeat/protos/mongodb/mongodb.go
@@ -55,9 +55,7 @@ type transactionKey struct {
 	id  int
 }
 
-var (
-	unmatchedRequests = monitoring.NewInt(nil, "mongodb.unmatched_requests")
-)
+var unmatchedRequests = monitoring.NewInt(nil, "mongodb.unmatched_requests")
 
 func init() {
 	protos.Register("mongodb", New)
@@ -218,7 +216,6 @@ func (mongodb *mongodbPlugin) handleMongodb(
 	tcptuple *common.TCPTuple,
 	dir uint8,
 ) {
-
 	m.tcpTuple = *tcptuple
 	m.direction = dir
 	m.cmdlineTuple = mongodb.watcher.FindProcessesTupleTCP(tcptuple.IPPort())
@@ -345,11 +342,12 @@ func reconstructQuery(t *transaction, full bool) (query string) {
 		if !full {
 			// remove the actual data.
 			// TODO: review if we need to add other commands here
-			if t.method == "insert" {
+			switch t.method {
+			case "insert":
 				params, err = doc2str(copyMapWithoutKey(t.params, "documents"))
-			} else if t.method == "update" {
+			case "update":
 				params, err = doc2str(copyMapWithoutKey(t.params, "updates"))
-			} else if t.method == "findandmodify" {
+			case "findandmodify":
 				params, err = doc2str(copyMapWithoutKey(t.params, "update"))
 			}
 		} else {
diff --git a/packetbeat/protos/mongodb/mongodb_parser.go b/packetbeat/protos/mongodb/mongodb_parser.go
index a5ff5fa0625..1abc6f890f2 100644
--- a/packetbeat/protos/mongodb/mongodb_parser.go
+++ b/packetbeat/protos/mongodb/mongodb_parser.go
@@ -116,10 +116,26 @@ func mongodbMessageParser(s *stream) (bool, bool) {
 // see http://docs.mongodb.org/meta-driver/latest/legacy/mongodb-wire-protocol/#op-reply
 func opReplyParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	_, err := d.readInt32() // ignore flags for now
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
+		return false, false
+	}
 	m.event["cursorId"], err = d.readInt64()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
+		return false, false
+	}
 	m.event["startingFrom"], err = d.readInt32()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
+		return false, false
+	}
 
 	numberReturned, err := d.readInt32()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
+		return false, false
+	}
 	m.event["numberReturned"] = numberReturned
 
 	debugf("Prepare to read %d document from reply", m.event["numberReturned"])
@@ -128,15 +144,27 @@ func opReplyParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	for i := 0; i < numberReturned; i++ {
 		var document bson.M
 		document, err = d.readDocument()
+		if err != nil {
+			logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
+			return false, false
+		}
 
 		// Check if the result is actually an error
 		if i == 0 {
 			if mongoError, present := document["$err"]; present {
 				m.error, err = doc2str(mongoError)
+				if err != nil {
+					logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
+					return false, false
+				}
 			}
 
 			if writeErrors, present := document["writeErrors"]; present {
 				m.error, err = doc2str(writeErrors)
+				if err != nil {
+					logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
+					return false, false
+				}
 			}
 		}
 
@@ -144,10 +172,6 @@ func opReplyParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	}
 	m.documents = documents
 
-	if err != nil {
-		logp.Err("An error occurred while parsing OP_REPLY message: %s", err)
-		return false, false
-	}
 	return true, true
 }
 
@@ -163,12 +187,26 @@ func opMsgLegacyParse(d *decoder, m *mongodbMessage) (bool, bool) {
 
 func opUpdateParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	_, err := d.readInt32() // always ZERO, a slot reserved in the protocol for future use
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_UPDATE message: %s", err)
+		return false, false
+	}
 	m.event["fullCollectionName"], err = d.readCStr()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_UPDATE message: %s", err)
+		return false, false
+	}
 	_, err = d.readInt32() // ignore flags for now
-
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_UPDATE message: %s", err)
+		return false, false
+	}
 	m.event["selector"], err = d.readDocumentStr()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_UPDATE message: %s", err)
+		return false, false
+	}
 	m.event["update"], err = d.readDocumentStr()
-
 	if err != nil {
 		logp.Err("An error occurred while parsing OP_UPDATE message: %s", err)
 		return false, false
@@ -179,6 +217,10 @@ func opUpdateParse(d *decoder, m *mongodbMessage) (bool, bool) {
 
 func opInsertParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	_, err := d.readInt32() // ignore flags for now
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_INSERT message: %s", err)
+		return false, false
+	}
 	m.event["fullCollectionName"], err = d.readCStr()
 
 	// TODO parse bson documents
@@ -230,11 +272,27 @@ func isDatabaseCommand(key string, val interface{}) bool {
 
 func opQueryParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	_, err := d.readInt32() // ignore flags for now
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_QUERY message: %s", err)
+		return false, false
+	}
 	fullCollectionName, err := d.readCStr()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_QUERY message: %s", err)
+		return false, false
+	}
 	m.event["fullCollectionName"] = fullCollectionName
 
 	m.event["numberToSkip"], err = d.readInt32()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_QUERY message: %s", err)
+		return false, false
+	}
 	m.event["numberToReturn"], err = d.readInt32()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_QUERY message: %s", err)
+		return false, false
+	}
 
 	query, err := d.readDocument()
 	if d.i < len(d.in) {
@@ -275,10 +333,21 @@ func opQueryParse(d *decoder, m *mongodbMessage) (bool, bool) {
 
 func opGetMoreParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	_, err := d.readInt32() // always ZERO, a slot reserved in the protocol for future use
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_GET_MORE message: %s", err)
+		return false, false
+	}
 	m.event["fullCollectionName"], err = d.readCStr()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_GET_MORE message: %s", err)
+		return false, false
+	}
 	m.event["numberToReturn"], err = d.readInt32()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_GET_MORE message: %s", err)
+		return false, false
+	}
 	m.event["cursorId"], err = d.readInt64()
-
 	if err != nil {
 		logp.Err("An error occurred while parsing OP_GET_MORE message: %s", err)
 		return false, false
@@ -288,11 +357,21 @@ func opGetMoreParse(d *decoder, m *mongodbMessage) (bool, bool) {
 
 func opDeleteParse(d *decoder, m *mongodbMessage) (bool, bool) {
 	_, err := d.readInt32() // always ZERO, a slot reserved in the protocol for future use
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_DELETE message: %s", err)
+		return false, false
+	}
 	m.event["fullCollectionName"], err = d.readCStr()
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_DELETE message: %s", err)
+		return false, false
+	}
 	_, err = d.readInt32() // ignore flags for now
-
+	if err != nil {
+		logp.Err("An error occurred while parsing OP_DELETE message: %s", err)
+		return false, false
+	}
 	m.event["selector"], err = d.readDocumentStr()
-
 	if err != nil {
 		logp.Err("An error occurred while parsing OP_DELETE message: %s", err)
 		return false, false
@@ -405,7 +484,6 @@ func (d *decoder) readByte() (byte, error) {
 
 func (d *decoder) readInt32() (int, error) {
 	b, err := d.readBytes(4)
-
 	if err != nil {
 		return 0, err
 	}
@@ -418,7 +496,6 @@ func (d *decoder) readInt32() (int, error) {
 
 func (d *decoder) readInt64() (int, error) {
 	b, err := d.readBytes(8)
-
 	if err != nil {
 		return 0, err
 	}
@@ -436,6 +513,9 @@ func (d *decoder) readInt64() (int, error) {
 func (d *decoder) readDocument() (bson.M, error) {
 	start := d.i
 	documentLength, err := d.readInt32()
+	if err != nil {
+		return nil, err
+	}
 	d.i = start + documentLength
 	if len(d.in) < d.i {
 		return nil, errors.New("document out of bounds")
@@ -461,6 +541,9 @@ func doc2str(documentMap interface{}) (string, error) {
 
 func (d *decoder) readDocumentStr() (string, error) {
 	documentMap, err := d.readDocument()
+	if err != nil {
+		return "", err
+	}
 	document, err := doc2str(documentMap)
 	return document, err
 }
diff --git a/packetbeat/protos/mongodb/mongodb_test.go b/packetbeat/protos/mongodb/mongodb_test.go
index ece0e1cf4aa..a1415dfa0a2 100644
--- a/packetbeat/protos/mongodb/mongodb_test.go
+++ b/packetbeat/protos/mongodb/mongodb_test.go
@@ -170,6 +170,7 @@ func TestSimpleFindLimit1_split(t *testing.T) {
 			"1b000000013000e6762ff7c97652c001" +
 			"3100d5b14ae9996c4440000273747265" +
 			"657400100000004d6f72726973205061")
+	assert.NoError(t, err)
 
 	respData2, err := hex.DecodeString(
 		"726b2041766500027a6970636f646500" +
@@ -183,6 +184,7 @@ func TestSimpleFindLimit1_split(t *testing.T) {
 			"0000000964617465000044510a410100" +
 			"00026772616465000200000041001073" +
 			"636f72650006000000000332002b0000")
+	assert.NoError(t, err)
 
 	respData3, err := hex.DecodeString(
 		"00096461746500009cda693c01000002" +
diff --git a/packetbeat/protos/mysql/config.go b/packetbeat/protos/mysql/config.go
index d53429c3a2c..0c634b98291 100644
--- a/packetbeat/protos/mysql/config.go
+++ b/packetbeat/protos/mysql/config.go
@@ -31,13 +31,11 @@ type mysqlConfig struct {
 	StatementTimeout      time.Duration `config:"statement_timeout"`
 }
 
-var (
-	defaultConfig = mysqlConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		MaxRowLength:     1024,
-		MaxRows:          10,
-		StatementTimeout: 3600 * time.Second,
-	}
-)
+var defaultConfig = mysqlConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	MaxRowLength:     1024,
+	MaxRows:          10,
+	StatementTimeout: 3600 * time.Second,
+}
diff --git a/packetbeat/protos/mysql/mysql.go b/packetbeat/protos/mysql/mysql.go
index 1553bdf9901..49ca17ece85 100644
--- a/packetbeat/protos/mysql/mysql.go
+++ b/packetbeat/protos/mysql/mysql.go
@@ -62,8 +62,6 @@ type mysqlMessage struct {
 	numberOfRows   int
 	numberOfFields int
 	size           uint64
-	fields         []string
-	rows           [][]string
 	tables         string
 	isOK           bool
 	affectedRows   uint64
@@ -83,7 +81,6 @@ type mysqlMessage struct {
 
 	statementID    int
 	numberOfParams int
-	params         []string
 }
 
 type mysqlTransaction struct {
@@ -337,7 +334,7 @@ func mysqlMessageParser(s *mysqlStream) (bool, bool) {
 				return true, false
 			}
 
-			s.parseOffset += 4 //header
+			s.parseOffset += 4 // header
 			s.parseOffset += int(m.packetLength)
 			m.end = s.parseOffset
 			if m.isRequest {
@@ -347,7 +344,6 @@ func mysqlMessageParser(s *mysqlStream) (bool, bool) {
 				} else {
 					m.query = string(s.data[m.start+5 : m.end])
 				}
-
 			} else if m.isOK {
 				// affected rows
 				affectedRows, off, complete, err := readLinteger(s.data, m.start+5)
@@ -475,7 +471,7 @@ func mysqlMessageParser(s *mysqlStream) (bool, bool) {
 				return true, false
 			}
 
-			s.parseOffset += 4 //header
+			s.parseOffset += 4 // header
 
 			if s.data[s.parseOffset] == 0xfe {
 				logp.Debug("mysqldetailed", "Received EOF packet")
@@ -553,8 +549,8 @@ func (mysql *mysqlPlugin) ConnectionTimeout() time.Duration {
 }
 
 func (mysql *mysqlPlugin) Parse(pkt *protos.Packet, tcptuple *common.TCPTuple,
-	dir uint8, private protos.ProtocolData) protos.ProtocolData {
-
+	dir uint8, private protos.ProtocolData,
+) protos.ProtocolData {
 	defer logp.Recover("ParseMysql exception")
 
 	priv := mysqlPrivateData{}
@@ -613,8 +609,8 @@ func (mysql *mysqlPlugin) Parse(pkt *protos.Packet, tcptuple *common.TCPTuple,
 }
 
 func (mysql *mysqlPlugin) GapInStream(tcptuple *common.TCPTuple, dir uint8,
-	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool) {
-
+	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool,
+) {
 	defer logp.Recover("GapInStream(mysql) exception")
 
 	if private == nil {
@@ -642,16 +638,16 @@ func (mysql *mysqlPlugin) GapInStream(tcptuple *common.TCPTuple, dir uint8,
 }
 
 func (mysql *mysqlPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
-	private protos.ProtocolData) protos.ProtocolData {
-
+	private protos.ProtocolData,
+) protos.ProtocolData {
 	// TODO: check if we have data pending and either drop it to free
 	// memory or send it up the stack.
 	return private
 }
 
 func handleMysql(mysql *mysqlPlugin, m *mysqlMessage, tcptuple *common.TCPTuple,
-	dir uint8, rawMsg []byte) {
-
+	dir uint8, rawMsg []byte,
+) {
 	m.tcpTuple = *tcptuple
 	m.direction = dir
 	m.cmdlineTuple = mysql.watcher.FindProcessesTupleTCP(tcptuple.IPPort())
@@ -689,9 +685,10 @@ func (mysql *mysqlPlugin) receivedMysqlRequest(msg *mysqlMessage) {
 		trans.statementID = msg.statementID
 		stmts := mysql.getStmtsMap(msg.tcpTuple.Hashable())
 		if stmts == nil {
-			if msg.typ == mysqlCmdStmtExecute {
+			switch msg.typ {
+			case mysqlCmdStmtExecute:
 				trans.query = "Request Execute Statement"
-			} else if msg.typ == mysqlCmdStmtClose {
+			case mysqlCmdStmtClose:
 				trans.query = "Request Close Statement"
 			}
 			trans.notes = append(trans.notes, "The actual query being used is unknown")
@@ -699,7 +696,8 @@ func (mysql *mysqlPlugin) receivedMysqlRequest(msg *mysqlMessage) {
 			trans.bytesIn = msg.size
 			return
 		}
-		if msg.typ == mysqlCmdStmtExecute {
+		switch msg.typ {
+		case mysqlCmdStmtExecute:
 			if value, ok := stmts[trans.statementID]; ok {
 				trans.query = value.query
 				// parse parameters
@@ -711,7 +709,7 @@ func (mysql *mysqlPlugin) receivedMysqlRequest(msg *mysqlMessage) {
 				trans.bytesIn = msg.size
 				return
 			}
-		} else if msg.typ == mysqlCmdStmtClose {
+		case mysqlCmdStmtClose:
 			delete(stmts, trans.statementID)
 			trans.query = "CmdStmtClose"
 			mysql.transactions.Delete(tuple.Hashable())
@@ -899,7 +897,7 @@ func (mysql *mysqlPlugin) parseMysqlExecuteStatement(data []byte, stmtdata *mysq
 			valueString := strconv.Itoa(int(binary.LittleEndian.Uint32(data[paramOffset:])))
 			paramString = append(paramString, valueString)
 			paramOffset += 4
-		//FIELD_TYPE_FLOAT
+		// FIELD_TYPE_FLOAT
 		case 0x04:
 			paramString = append(paramString, "TYPE_FLOAT")
 			paramOffset += 4
@@ -1012,19 +1010,19 @@ func (mysql *mysqlPlugin) parseMysqlResponse(data []byte) ([]string, [][]string)
 		return []string{}, [][]string{}
 	}
 
-	fields := []string{}
-	rows := [][]string{}
-
 	if len(data) < 5 {
-		logp.Warn("Invalid response: data less than 4 bytes")
+		logp.Warn("Invalid response: data less than 5 bytes")
 		return []string{}, [][]string{}
 	}
 
-	if data[4] == 0x00 {
+	fields := []string{}
+	rows := [][]string{}
+	switch data[4] {
+	case 0x00:
 		// OK response
-	} else if data[4] == 0xff {
+	case 0xff:
 		// Error response
-	} else {
+	default:
 		offset := 5
 
 		logp.Debug("mysql", "Data len: %d", len(data))
@@ -1100,7 +1098,7 @@ func (mysql *mysqlPlugin) parseMysqlResponse(data []byte) ([]string, [][]string)
 
 			if data[offset+4] == 0xfe {
 				// EOF
-				offset += length + 4
+				offset += length + 4 // ineffassign
 				break
 			}
 
diff --git a/packetbeat/protos/mysql/mysql_test.go b/packetbeat/protos/mysql/mysql_test.go
index 309fd45cb0f..dd942399073 100644
--- a/packetbeat/protos/mysql/mysql_test.go
+++ b/packetbeat/protos/mysql/mysql_test.go
@@ -49,10 +49,6 @@ func (e *eventStore) publish(event beat.Event) {
 	e.events = append(e.events, event)
 }
 
-func (e *eventStore) empty() bool {
-	return len(e.events) == 0
-}
-
 func mysqlModForTests(store *eventStore) *mysqlPlugin {
 	callback := func(beat.Event) {}
 	if store != nil {
@@ -110,6 +106,7 @@ func TestMySQLParser_simpleRequest(t *testing.T) {
 		t.Errorf("Wrong message size %d", stream.message.size)
 	}
 }
+
 func TestMySQLParser_OKResponse(t *testing.T) {
 	data := []byte(
 		"0700000100010401000000")
@@ -363,11 +360,11 @@ func TestParseMySQL_simpleUpdateResponse(t *testing.T) {
 	var tuple common.TCPTuple
 	var private mysqlPrivateData
 
-	var countHandleMysql = 0
+	countHandleMysql := 0
 
 	mysql.handleMysql = func(mysql *mysqlPlugin, m *mysqlMessage, tcp *common.TCPTuple,
-		dir uint8, raw_msg []byte) {
-
+		dir uint8, raw_msg []byte,
+	) {
 		countHandleMysql++
 	}
 
@@ -404,11 +401,11 @@ func TestParseMySQL_threeResponses(t *testing.T) {
 	var tuple common.TCPTuple
 	var private mysqlPrivateData
 
-	var countHandleMysql = 0
+	countHandleMysql := 0
 
 	mysql.handleMysql = func(mysql *mysqlPlugin, m *mysqlMessage, tcptuple *common.TCPTuple,
-		dir uint8, raw_msg []byte) {
-
+		dir uint8, raw_msg []byte,
+	) {
 		countHandleMysql++
 	}
 
@@ -431,7 +428,6 @@ func TestParseMySQL_splitResponse(t *testing.T) {
 			"3b00000303646566086d696e697477697404706f737404706f73740d706f73745f757365726e616d6508757365726e616d650c2100f0000000fd0000000000" +
 			"3500000403646566086d696e697477697404706f737404706f73740a706f73745f7469746c65057469746c650c2100f0000000fd0000000000" +
 			"3300000503646566086d696e697477697404706f737404706f737409706f73745f626f647904626f64790c2100fdff0200fc1000000000")
-
 	if err != nil {
 		t.Errorf("Failed to decode string")
 	}
@@ -446,11 +442,11 @@ func TestParseMySQL_splitResponse(t *testing.T) {
 	var tuple common.TCPTuple
 	var private mysqlPrivateData
 
-	var countHandleMysql = 0
+	countHandleMysql := 0
 
 	mysql.handleMysql = func(mysql *mysqlPlugin, m *mysqlMessage, tcptuple *common.TCPTuple,
-		dir uint8, raw_msg []byte) {
-
+		dir uint8, raw_msg []byte,
+	) {
 		countHandleMysql++
 	}
 
@@ -623,12 +619,18 @@ func Test_parseMysqlResponse_invalid(t *testing.T) {
 		{0x05, 0x00, 0x00, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00},
 		{0x05, 0x00, 0x00, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00},
 		{0x05, 0x00, 0x00, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00},
-		{0x05, 0x00, 0x00, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00,
-			0x01, 0x00},
-		{0x15, 0x00, 0x00, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00,
-			0x01, 0x00, 0x01},
-		{0x15, 0x00, 0x00, 0x01, 0x01, 0x05, 0x15, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00,
-			0x01, 0x00, 0x01, 0x00},
+		{
+			0x05, 0x00, 0x00, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00,
+			0x01, 0x00,
+		},
+		{
+			0x15, 0x00, 0x00, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00,
+			0x01, 0x00, 0x01,
+		},
+		{
+			0x15, 0x00, 0x00, 0x01, 0x01, 0x05, 0x15, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00,
+			0x01, 0x00, 0x01, 0x00,
+		},
 	}
 
 	for _, input := range tests {
@@ -638,12 +640,14 @@ func Test_parseMysqlResponse_invalid(t *testing.T) {
 	}
 
 	tests = [][]byte{
-		{0x15, 0x00, 0x00, 0x01, 0x01,
-			0x0b, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0xfe, 0x00, 0x01, //field
+		{
+			0x15, 0x00, 0x00, 0x01, 0x01,
+			0x0b, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0xfe, 0x00, 0x01, // field
 			0x01, 0x00, 0x00, 0x00, 0xfe, // EOF
 		},
-		{0x15, 0x00, 0x00, 0x01, 0x01,
-			0x0b, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0xfe, 0x00, 0x01, //field
+		{
+			0x15, 0x00, 0x00, 0x01, 0x01,
+			0x0b, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0xfe, 0x00, 0x01, // field
 			0x01, 0x00, 0x00, 0x00, 0xfe, // EOF
 			0x00, 0x00,
 		},
@@ -668,7 +672,7 @@ func Test_PreparedStatement(t *testing.T) {
 		packet := protos.Packet{Payload: rawData}
 
 		var private protos.ProtocolData
-		private = mysql.Parse(&packet, tcpTuple, dir, private)
+		mysql.Parse(&packet, tcpTuple, dir, private)
 	}
 
 	send(tcp.TCPDirectionOriginal, "c00000001673656c6563742064697374696e637420636f756e742864697374696e63742070757263686173656465305f2e69642920617320636f6c5f305f305f2066726f6d2070757263686173655f64656d616e642070757263686173656465305f2077686572652070757263686173656465305f2e636861696e5f6d61737465723d3f20616e642070757263686173656465305f2e6372656174655f74696d653e3d3f20616e642070757263686173656465305f2e6372656174655f74696d653c3d3f")
diff --git a/packetbeat/protos/nfs/config.go b/packetbeat/protos/nfs/config.go
index 639bdad525d..e23672024c8 100644
--- a/packetbeat/protos/nfs/config.go
+++ b/packetbeat/protos/nfs/config.go
@@ -27,10 +27,8 @@ type rpcConfig struct {
 	config.ProtocolCommon `config:",inline"`
 }
 
-var (
-	defaultConfig = rpcConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: 1 * time.Minute,
-		},
-	}
-)
+var defaultConfig = rpcConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: 1 * time.Minute,
+	},
+}
diff --git a/packetbeat/protos/nfs/request_handler.go b/packetbeat/protos/nfs/request_handler.go
index fea417f4dc1..1225f9f6012 100644
--- a/packetbeat/protos/nfs/request_handler.go
+++ b/packetbeat/protos/nfs/request_handler.go
@@ -41,9 +41,7 @@ var acceptStatus = [...]string{
 	"system_err",
 }
 
-var (
-	unmatchedRequests = monitoring.NewInt(nil, "nfs.unmatched_requests")
-)
+var unmatchedRequests = monitoring.NewInt(nil, "nfs.unmatched_requests")
 
 // called by Cache, when re reply seen within expected time window
 func (r *rpc) handleExpiredPacket(nfs *nfs) {
diff --git a/packetbeat/protos/nfs/rpc.go b/packetbeat/protos/nfs/rpc.go
index 9cde7ab5aac..64fffe47606 100644
--- a/packetbeat/protos/nfs/rpc.go
+++ b/packetbeat/protos/nfs/rpc.go
@@ -126,7 +126,6 @@ func (r *rpc) Parse(
 	dir uint8,
 	private protos.ProtocolData,
 ) protos.ProtocolData {
-
 	defer logp.Recover("ParseRPC exception")
 
 	conn := ensureRPCConnection(private)
@@ -140,8 +139,8 @@ func (r *rpc) Parse(
 
 // Called when the FIN flag is seen in the TCP stream.
 func (r *rpc) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
-	private protos.ProtocolData) protos.ProtocolData {
-
+	private protos.ProtocolData,
+) protos.ProtocolData {
 	defer logp.Recover("ReceivedFinRpc exception")
 
 	// forced by TCP interface
@@ -151,8 +150,8 @@ func (r *rpc) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
 // Called when a packets are missing from the tcp
 // stream.
 func (r *rpc) GapInStream(tcptuple *common.TCPTuple, dir uint8,
-	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool) {
-
+	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool,
+) {
 	defer logp.Recover("GapInRpcStream exception")
 
 	// forced by TCP interface
@@ -199,7 +198,6 @@ func (r *rpc) handleRPCFragment(
 	tcptuple *common.TCPTuple,
 	dir uint8,
 ) *rpcConnectionData {
-
 	st := conn.streams[dir]
 	if st == nil {
 		st = newStream(pkt, tcptuple)
diff --git a/packetbeat/protos/nfs/xdr.go b/packetbeat/protos/nfs/xdr.go
index de63fc755a2..168fb274cfd 100644
--- a/packetbeat/protos/nfs/xdr.go
+++ b/packetbeat/protos/nfs/xdr.go
@@ -40,24 +40,12 @@ func (r *xdr) size() int {
 	return len(r.data)
 }
 
-func (r *xdr) getInt() int32 {
-	i := int32(binary.BigEndian.Uint32(r.data[r.offset : r.offset+4]))
-	r.offset += 4
-	return int32(i)
-}
-
 func (r *xdr) getUInt() uint32 {
 	i := uint32(binary.BigEndian.Uint32(r.data[r.offset : r.offset+4]))
 	r.offset += 4
 	return i
 }
 
-func (r *xdr) getHyper() int64 {
-	i := int64(binary.BigEndian.Uint64(r.data[r.offset : r.offset+8]))
-	r.offset += 8
-	return i
-}
-
 func (r *xdr) getUHyper() uint64 {
 	i := uint64(binary.BigEndian.Uint64(r.data[r.offset : r.offset+8]))
 	r.offset += 8
diff --git a/packetbeat/protos/pgsql/config.go b/packetbeat/protos/pgsql/config.go
index 54a9a1b9e2e..13c11531409 100644
--- a/packetbeat/protos/pgsql/config.go
+++ b/packetbeat/protos/pgsql/config.go
@@ -28,12 +28,10 @@ type pgsqlConfig struct {
 	MaxRows               int `config:"max_rows"`
 }
 
-var (
-	defaultConfig = pgsqlConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		MaxRowLength: 1024,
-		MaxRows:      10,
-	}
-)
+var defaultConfig = pgsqlConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	MaxRowLength: 1024,
+	MaxRows:      10,
+}
diff --git a/packetbeat/protos/pgsql/parse.go b/packetbeat/protos/pgsql/parse.go
index a7bcdb44770..9a302f99a18 100644
--- a/packetbeat/protos/pgsql/parse.go
+++ b/packetbeat/protos/pgsql/parse.go
@@ -158,7 +158,7 @@ func (pgsql *pgsqlPlugin) parseSimpleQuery(s *pgsqlStream, length int) (bool, bo
 	m.start = s.parseOffset
 	m.isRequest = true
 
-	s.parseOffset++ //type
+	s.parseOffset++ // type
 	s.parseOffset += length
 	m.end = s.parseOffset
 	m.size = uint64(m.end - m.start)
@@ -190,8 +190,8 @@ func (pgsql *pgsqlPlugin) parseRowDescription(s *pgsqlStream, length int) (bool,
 	}
 	pgsql.detailf("Fields: %s", m.fields)
 
-	s.parseOffset++         //type
-	s.parseOffset += length //length
+	s.parseOffset++         // type
+	s.parseOffset += length // length
 	s.parseState = pgsqlGetDataState
 	return pgsql.parseMessageData(s)
 }
@@ -238,7 +238,7 @@ func (pgsql *pgsqlPlugin) parseCommandComplete(s *pgsqlStream, length int) (bool
 	m.isOK = true
 	m.toExport = true
 
-	s.parseOffset++ //type
+	s.parseOffset++ // type
 	name, err := pgsqlString(s.data[s.parseOffset+4:], length-4)
 	if err != nil {
 		return false, false
@@ -276,10 +276,10 @@ func (pgsql *pgsqlPlugin) parseErrorResponse(s *pgsqlStream, length int) (bool,
 	m.isError = true
 	m.toExport = true
 
-	s.parseOffset++ //type
+	s.parseOffset++ // type
 	pgsql.parseError(s, s.data[s.parseOffset+4:s.parseOffset+length])
 
-	s.parseOffset += length //length
+	s.parseOffset += length // length
 	m.end = s.parseOffset
 	m.size = uint64(m.end - m.start)
 
@@ -294,7 +294,7 @@ func (pgsql *pgsqlPlugin) parseExtReq(s *pgsqlStream, length int) (bool, bool) {
 	m.start = s.parseOffset
 	m.isRequest = true
 
-	s.parseOffset++ //type
+	s.parseOffset++ // type
 	s.parseOffset += length
 	m.end = s.parseOffset
 	m.size = uint64(m.end - m.start)
@@ -326,7 +326,7 @@ func (pgsql *pgsqlPlugin) parseExtResp(s *pgsqlStream, length int) (bool, bool)
 	m.isOK = true
 	m.toExport = true
 
-	s.parseOffset++ //type
+	s.parseOffset++ // type
 	s.parseOffset += length
 	pgsql.detailf("Parse completion in an extended query response")
 	s.parseState = pgsqlGetDataState
@@ -336,7 +336,7 @@ func (pgsql *pgsqlPlugin) parseExtResp(s *pgsqlStream, length int) (bool, bool)
 func (pgsql *pgsqlPlugin) parseSkipMessage(s *pgsqlStream, length int) (bool, bool) {
 	// TODO: add info from NoticeResponse in case there are warning messages for a query
 	// ignore command
-	s.parseOffset++ //type
+	s.parseOffset++ // type
 	s.parseOffset += length
 
 	m := s.message
@@ -615,21 +615,21 @@ func (pgsql *pgsqlPlugin) parseMessageExtendedQuery(s *pgsqlStream) (bool, bool)
 			// skip type
 			s.parseOffset++
 			s.parseOffset += length
-			//TODO: pgsql.parseBind(s)
+			// TODO: pgsql.parseBind(s)
 		case 'D':
 			// Bind -> Describe
 
 			// skip type
 			s.parseOffset++
 			s.parseOffset += length
-			//TODO: pgsql.parseDescribe(s)
+			// TODO: pgsql.parseDescribe(s)
 		case 'E':
 			// Bind(or Describe) -> Execute
 
 			// skip type
 			s.parseOffset++
 			s.parseOffset += length
-			//TODO: pgsql.parseExecute(s)
+			// TODO: pgsql.parseExecute(s)
 		case 'S':
 			// Execute -> Sync
 
diff --git a/packetbeat/protos/pgsql/pgsql.go b/packetbeat/protos/pgsql/pgsql.go
index 5ad6f6e305a..20ad2fc5461 100644
--- a/packetbeat/protos/pgsql/pgsql.go
+++ b/packetbeat/protos/pgsql/pgsql.go
@@ -126,13 +126,9 @@ const (
 	cancelRequest
 )
 
-var (
-	errInvalidLength = errors.New("invalid length")
-)
+var errInvalidLength = errors.New("invalid length")
 
-var (
-	unmatchedResponses = monitoring.NewInt(nil, "pgsql.unmatched_responses")
-)
+var unmatchedResponses = monitoring.NewInt(nil, "pgsql.unmatched_responses")
 
 func init() {
 	protos.Register("pgsql", New)
@@ -240,8 +236,8 @@ func (pgsql *pgsqlPlugin) ConnectionTimeout() time.Duration {
 }
 
 func (pgsql *pgsqlPlugin) Parse(pkt *protos.Packet, tcptuple *common.TCPTuple,
-	dir uint8, private protos.ProtocolData) protos.ProtocolData {
-
+	dir uint8, private protos.ProtocolData,
+) protos.ProtocolData {
 	defer logp.Recover("ParsePgsql exception")
 
 	priv := pgsqlPrivateData{}
@@ -334,8 +330,8 @@ func messageHasEnoughData(msg *pgsqlMessage) bool {
 
 // Called when there's a drop packet
 func (pgsql *pgsqlPlugin) GapInStream(tcptuple *common.TCPTuple, dir uint8,
-	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool) {
-
+	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool,
+) {
 	defer logp.Recover("GapInPgsqlStream exception")
 
 	if private == nil {
@@ -378,8 +374,8 @@ func (pgsql *pgsqlPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
 }
 
 var handlePgsql = func(pgsql *pgsqlPlugin, m *pgsqlMessage, tcptuple *common.TCPTuple,
-	dir uint8, raw_msg []byte) {
-
+	dir uint8, raw_msg []byte,
+) {
 	m.tcpTuple = *tcptuple
 	m.direction = dir
 	m.cmdlineTuple = pgsql.watcher.FindProcessesTupleTCP(tcptuple.IPPort())
@@ -433,7 +429,7 @@ func (pgsql *pgsqlPlugin) receivedPgsqlRequest(msg *pgsqlMessage) {
 func (pgsql *pgsqlPlugin) receivedPgsqlResponse(msg *pgsqlMessage) {
 	tuple := msg.tcpTuple
 	transList := pgsql.getTransaction(tuple.Hashable())
-	if transList == nil || len(transList) == 0 {
+	if len(transList) == 0 {
 		pgsql.debugf("Response from unknown transaction. Ignoring.")
 		unmatchedResponses.Add(1)
 		return
@@ -511,8 +507,8 @@ func (pgsql *pgsqlPlugin) publishTransaction(t *pgsqlTransaction) {
 }
 
 func (pgsql *pgsqlPlugin) removeTransaction(transList []*pgsqlTransaction,
-	tuple common.TCPTuple, index int) *pgsqlTransaction {
-
+	tuple common.TCPTuple, index int,
+) *pgsqlTransaction {
 	trans := transList[index]
 	transList = append(transList[:index], transList[index+1:]...)
 	if len(transList) == 0 {
diff --git a/packetbeat/protos/pgsql/pgsql_test.go b/packetbeat/protos/pgsql/pgsql_test.go
index 328b31e28c2..82075eaacae 100644
--- a/packetbeat/protos/pgsql/pgsql_test.go
+++ b/packetbeat/protos/pgsql/pgsql_test.go
@@ -46,10 +46,6 @@ func (e *eventStore) publish(event beat.Event) {
 	e.events = append(e.events, event)
 }
 
-func (e *eventStore) empty() bool {
-	return len(e.events) == 0
-}
-
 func pgsqlModForTests(store *eventStore) *pgsqlPlugin {
 	callback := func(beat.Event) {}
 	if store != nil {
@@ -234,11 +230,11 @@ func TestPgsqlParser_threeResponses(t *testing.T) {
 	}
 	var tuple common.TCPTuple
 	var private pgsqlPrivateData
-	var countHandlePgsql = 0
+	countHandlePgsql := 0
 
 	pgsql.handlePgsql = func(pgsql *pgsqlPlugin, m *pgsqlMessage, tcptuple *common.TCPTuple,
-		dir uint8, raw_msg []byte) {
-
+		dir uint8, raw_msg []byte,
+	) {
 		countHandlePgsql++
 	}
 
diff --git a/packetbeat/protos/protos.go b/packetbeat/protos/protos.go
index e0343a0ee87..39dc09d8b7d 100644
--- a/packetbeat/protos/protos.go
+++ b/packetbeat/protos/protos.go
@@ -79,7 +79,6 @@ type Protocols interface {
 	BpfFilter(withVlans bool, withICMP bool) string
 	GetTCP(proto Protocol) TCPPlugin
 	GetUDP(proto Protocol) UDPPlugin
-
 	GetAllTCP() map[Protocol]TCPPlugin
 	GetAllUDP() map[Protocol]UDPPlugin
 
diff --git a/packetbeat/protos/protos_test.go b/packetbeat/protos/protos_test.go
index 22269a192d2..b3c1a912069 100644
--- a/packetbeat/protos/protos_test.go
+++ b/packetbeat/protos/protos_test.go
@@ -70,9 +70,7 @@ func (proto *UDPProtocol) GetPorts() []int {
 	return proto.Ports
 }
 
-func (proto *UDPProtocol) ParseUDP(pkt *Packet) {
-	return
-}
+func (proto *UDPProtocol) ParseUDP(pkt *Packet) {}
 
 type TCPUDPProtocol TestProtocol
 
@@ -99,9 +97,7 @@ func (proto *TCPUDPProtocol) GapInStream(tcptuple *common.TCPTuple, dir uint8,
 	return private, true
 }
 
-func (proto *TCPUDPProtocol) ParseUDP(pkt *Packet) {
-	return
-}
+func (proto *TCPUDPProtocol) ParseUDP(pkt *Packet) {}
 
 func (proto *TCPUDPProtocol) ConnectionTimeout() time.Duration { return 0 }
 
diff --git a/packetbeat/protos/redis/config.go b/packetbeat/protos/redis/config.go
index beb1caed2e2..a1fd48f4149 100644
--- a/packetbeat/protos/redis/config.go
+++ b/packetbeat/protos/redis/config.go
@@ -27,14 +27,12 @@ type redisConfig struct {
 	QueueLimits           MessageQueueConfig `config:",inline"`
 }
 
-var (
-	defaultConfig = redisConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		QueueLimits: MessageQueueConfig{
-			MaxBytes:    1024 * 1024,
-			MaxMessages: 20000,
-		},
-	}
-)
+var defaultConfig = redisConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	QueueLimits: MessageQueueConfig{
+		MaxBytes:    1024 * 1024,
+		MaxMessages: 20000,
+	},
+}
diff --git a/packetbeat/protos/redis/redis.go b/packetbeat/protos/redis/redis.go
index 23dd1ad8696..a219e8a14f9 100644
--- a/packetbeat/protos/redis/redis.go
+++ b/packetbeat/protos/redis/redis.go
@@ -140,6 +140,7 @@ func (redis *redisPlugin) Parse(
 	}
 	return conn
 }
+
 func (redis *redisPlugin) newConnectionData() *redisConnectionData {
 	return &redisConnectionData{
 		requests:  NewMessageQueue(redis.queueConfig),
@@ -171,7 +172,6 @@ func (redis *redisPlugin) doParse(
 	tcptuple *common.TCPTuple,
 	dir uint8,
 ) *redisConnectionData {
-
 	st := conn.streams[dir]
 	if st == nil {
 		st = newStream(pkt.Ts, tcptuple)
@@ -339,8 +339,8 @@ func (redis *redisPlugin) newTransaction(requ, resp *redisMessage) beat.Event {
 }
 
 func (redis *redisPlugin) GapInStream(tcptuple *common.TCPTuple, dir uint8,
-	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool) {
-
+	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool,
+) {
 	// tsg: being packet loss tolerant is probably not very useful for Redis,
 	// because most requests/response tend to fit in a single packet.
 
@@ -348,8 +348,8 @@ func (redis *redisPlugin) GapInStream(tcptuple *common.TCPTuple, dir uint8,
 }
 
 func (redis *redisPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
-	private protos.ProtocolData) protos.ProtocolData {
-
+	private protos.ProtocolData,
+) protos.ProtocolData {
 	// TODO: check if we have pending data that we can send up the stack
 
 	return private
diff --git a/packetbeat/protos/sip/config.go b/packetbeat/protos/sip/config.go
index 58a92606e80..309558a225f 100644
--- a/packetbeat/protos/sip/config.go
+++ b/packetbeat/protos/sip/config.go
@@ -29,13 +29,11 @@ type config struct {
 	KeepOriginal       bool `config:"keep_original"`
 }
 
-var (
-	defaultConfig = config{
-		ProtocolCommon: cfg.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		ParseAuthorization: true,
-		ParseBody:          true,
-		KeepOriginal:       true,
-	}
-)
+var defaultConfig = config{
+	ProtocolCommon: cfg.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	ParseAuthorization: true,
+	ParseBody:          true,
+	KeepOriginal:       true,
+}
diff --git a/packetbeat/protos/sip/parser.go b/packetbeat/protos/sip/parser.go
index 8d49ad61742..db63f05b429 100644
--- a/packetbeat/protos/sip/parser.go
+++ b/packetbeat/protos/sip/parser.go
@@ -269,8 +269,7 @@ func parseVersion(s []byte) (uint8, uint8, error) {
 
 func (parser *parser) parseHeaders(pi *parsingInfo, m *message) error {
 	// check if it isn't headers end yet with /r/n/r/n
-	if !(len(pi.data)-pi.parseOffset >= 2 &&
-		bytes.Equal(pi.data[pi.parseOffset:pi.parseOffset+2], constCRLF)) {
+	if len(pi.data)-pi.parseOffset < 2 || !bytes.Equal(pi.data[pi.parseOffset:pi.parseOffset+2], constCRLF) {
 		offset, err := parser.parseHeader(m, pi.data[pi.parseOffset:])
 		if err != nil {
 			return err
diff --git a/packetbeat/protos/tcp/tcp.go b/packetbeat/protos/tcp/tcp.go
index e9db7b94897..51ac46346a0 100644
--- a/packetbeat/protos/tcp/tcp.go
+++ b/packetbeat/protos/tcp/tcp.go
@@ -61,9 +61,7 @@ type Processor interface {
 	Process(flow *flows.FlowID, hdr *layers.TCP, pkt *protos.Packet)
 }
 
-var (
-	droppedBecauseOfGaps = monitoring.NewInt(nil, "tcp.dropped_because_of_gaps")
-)
+var droppedBecauseOfGaps = monitoring.NewInt(nil, "tcp.dropped_because_of_gaps")
 
 type seqCompare int
 
@@ -271,7 +269,8 @@ func (tcp *TCP) getStream(pkt *protos.Packet) (stream TCPStream, created bool) {
 		id:       tcp.getID(),
 		tuple:    &pkt.Tuple,
 		protocol: protocol,
-		tcp:      tcp}
+		tcp:      tcp,
+	}
 	conn.tcptuple = common.TCPTupleFromIPPort(conn.tuple, conn.id)
 	tcp.streams.PutWithTimeout(pkt.Tuple.Hashable(), conn, timeout)
 	return TCPStream{conn: conn, dir: TCPDirectionOriginal}, true
@@ -289,16 +288,12 @@ func tcpSeqCompare(seq1, seq2 uint32) seqCompare {
 	}
 }
 
-func tcpSeqBefore(seq1 uint32, seq2 uint32) bool {
-	return int32(seq1-seq2) < 0
-}
-
 func tcpSeqBeforeEq(seq1 uint32, seq2 uint32) bool {
 	return int32(seq1-seq2) <= 0
 }
 
 func buildPortsMap(plugins map[protos.Protocol]protos.TCPPlugin) (map[uint16]protos.Protocol, error) {
-	var res = map[uint16]protos.Protocol{}
+	res := map[uint16]protos.Protocol{}
 
 	for proto, protoPlugin := range plugins {
 		for _, port := range protoPlugin.GetPorts() {
diff --git a/packetbeat/protos/tcp/tcp_test.go b/packetbeat/protos/tcp/tcp_test.go
index 9dd910799b6..5678924a7d6 100644
--- a/packetbeat/protos/tcp/tcp_test.go
+++ b/packetbeat/protos/tcp/tcp_test.go
@@ -41,9 +41,7 @@ const (
 	ClientIP   = "10.0.0.1"
 )
 
-var (
-	httpProtocol, mysqlProtocol, redisProtocol protos.Protocol
-)
+var httpProtocol, mysqlProtocol, redisProtocol protos.Protocol
 
 func init() {
 	new := func(_ bool, _ protos.Reporter, _ procs.ProcessesWatcher, _ *common.Config) (protos.Plugin, error) {
@@ -199,7 +197,7 @@ func (p protocols) GetUDP(proto protos.Protocol) protos.UDPPlugin        { retur
 func (p protocols) GetAll() map[protos.Protocol]protos.Plugin            { return nil }
 func (p protocols) GetAllTCP() map[protos.Protocol]protos.TCPPlugin      { return p.tcp }
 func (p protocols) GetAllUDP() map[protos.Protocol]protos.UDPPlugin      { return nil }
-func (p protocols) Register(proto protos.Protocol, plugin protos.Plugin) { return }
+func (p protocols) Register(proto protos.Protocol, plugin protos.Plugin) {}
 
 func TestTCSeqPayload(t *testing.T) {
 	type segment struct {
@@ -213,7 +211,8 @@ func TestTCSeqPayload(t *testing.T) {
 		expectedGaps  int
 		expectedState []byte
 	}{
-		{"No overlap",
+		{
+			"No overlap",
 			[]segment{
 				{1, []byte{1, 2, 3, 4, 5}},
 				{6, []byte{6, 7, 8, 9, 10}},
@@ -221,7 +220,8 @@ func TestTCSeqPayload(t *testing.T) {
 			0,
 			[]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
 		},
-		{"Gap drop state",
+		{
+			"Gap drop state",
 			[]segment{
 				{1, []byte{1, 2, 3, 4}},
 				{15, []byte{5, 6, 7, 8}},
@@ -229,7 +229,8 @@ func TestTCSeqPayload(t *testing.T) {
 			10,
 			[]byte{5, 6, 7, 8},
 		},
-		{"ACK same sequence number",
+		{
+			"ACK same sequence number",
 			[]segment{
 				{1, []byte{1, 2}},
 				{3, nil},
@@ -239,7 +240,8 @@ func TestTCSeqPayload(t *testing.T) {
 			0,
 			[]byte{1, 2, 3, 4, 5, 6},
 		},
-		{"ACK same sequence number 2",
+		{
+			"ACK same sequence number 2",
 			[]segment{
 				{1, nil},
 				{2, nil},
@@ -253,7 +255,8 @@ func TestTCSeqPayload(t *testing.T) {
 			0,
 			[]byte{1, 2, 3, 4, 5, 6, 7, 8},
 		},
-		{"Overlap, first segment bigger",
+		{
+			"Overlap, first segment bigger",
 			[]segment{
 				{1, []byte{1, 2}},
 				{3, []byte{3, 4}},
@@ -263,7 +266,8 @@ func TestTCSeqPayload(t *testing.T) {
 			0,
 			[]byte{1, 2, 3, 4, 5, 6},
 		},
-		{"Overlap, second segment bigger",
+		{
+			"Overlap, second segment bigger",
 			[]segment{
 				{1, []byte{1, 2}},
 				{3, []byte{3}},
@@ -273,7 +277,8 @@ func TestTCSeqPayload(t *testing.T) {
 			0,
 			[]byte{1, 2, 3, 4, 5, 6},
 		},
-		{"Overlap, covered",
+		{
+			"Overlap, covered",
 			[]segment{
 				{1, []byte{1, 2, 3, 4}},
 				{2, []byte{2, 3}},
diff --git a/packetbeat/protos/thrift/config.go b/packetbeat/protos/thrift/config.go
index f687da9ac0c..0d946a02438 100644
--- a/packetbeat/protos/thrift/config.go
+++ b/packetbeat/protos/thrift/config.go
@@ -34,16 +34,14 @@ type thriftConfig struct {
 	IdlFiles               []string `config:"idl_files"`
 }
 
-var (
-	defaultConfig = thriftConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		StringMaxSize:          200,
-		CollectionMaxSize:      15,
-		DropAfterNStructFields: 500,
-		TransportType:          "socket",
-		ProtocolType:           "binary",
-		CaptureReply:           true,
-	}
-)
+var defaultConfig = thriftConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	StringMaxSize:          200,
+	CollectionMaxSize:      15,
+	DropAfterNStructFields: 500,
+	TransportType:          "socket",
+	ProtocolType:           "binary",
+	CaptureReply:           true,
+}
diff --git a/packetbeat/protos/thrift/thrift.go b/packetbeat/protos/thrift/thrift.go
index d9778031d76..04c73747f7f 100644
--- a/packetbeat/protos/thrift/thrift.go
+++ b/packetbeat/protos/thrift/thrift.go
@@ -656,8 +656,8 @@ func (thrift *thriftPlugin) readStruct(data []byte) (value string, ok bool, comp
 }
 
 func (thrift *thriftPlugin) formatStruct(fields []thriftField, resolveNames bool,
-	fieldnames []*string) string {
-
+	fieldnames []*string,
+) string {
 	toJoin := []string{}
 	for i, field := range fields {
 		if i == thrift.collectionMaxSize {
@@ -746,7 +746,7 @@ func (thrift *thriftPlugin) readField(s *thriftStream) (ok bool, complete bool,
 
 func (thrift *thriftPlugin) messageParser(s *thriftStream) (bool, bool) {
 	var ok, complete bool
-	var m = s.message
+	m := s.message
 
 	logp.Debug("thriftdetailed", "messageParser called parseState=%v offset=%v",
 		s.parseState, s.parseOffset)
@@ -860,7 +860,7 @@ func (stream *thriftStream) prepareForNewMessage(flush bool) {
 	} else {
 		stream.data = stream.data[stream.parseOffset:]
 	}
-	//logp.Debug("thrift", "remaining data: [%s]", stream.data)
+	// logp.Debug("thrift", "remaining data: [%s]", stream.data)
 	stream.parseOffset = 0
 	stream.message = nil
 	stream.parseState = thriftStartState
@@ -871,8 +871,8 @@ type thriftPrivateData struct {
 }
 
 func (thrift *thriftPlugin) messageComplete(tcptuple *common.TCPTuple, dir uint8,
-	stream *thriftStream, priv *thriftPrivateData) {
-
+	stream *thriftStream, priv *thriftPrivateData,
+) {
 	flush := false
 
 	if stream.message.isRequest {
@@ -906,7 +906,6 @@ func (thrift *thriftPlugin) messageComplete(tcptuple *common.TCPTuple, dir uint8
 
 	// and reset message
 	stream.prepareForNewMessage(flush)
-
 }
 
 func (thrift *thriftPlugin) ConnectionTimeout() time.Duration {
@@ -914,8 +913,8 @@ func (thrift *thriftPlugin) ConnectionTimeout() time.Duration {
 }
 
 func (thrift *thriftPlugin) Parse(pkt *protos.Packet, tcptuple *common.TCPTuple, dir uint8,
-	private protos.ProtocolData) protos.ProtocolData {
-
+	private protos.ProtocolData,
+) protos.ProtocolData {
 	defer logp.Recover("ParseThrift exception")
 
 	priv := thriftPrivateData{}
@@ -1040,8 +1039,8 @@ func (thrift *thriftPlugin) receivedReply(msg *thriftMessage) {
 }
 
 func (thrift *thriftPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
-	private protos.ProtocolData) protos.ProtocolData {
-
+	private protos.ProtocolData,
+) protos.ProtocolData {
 	trans := thrift.getTransaction(tcptuple.Hashable())
 	if trans != nil {
 		if trans.request != nil && trans.reply == nil {
@@ -1055,8 +1054,8 @@ func (thrift *thriftPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
 }
 
 func (thrift *thriftPlugin) GapInStream(tcptuple *common.TCPTuple, dir uint8,
-	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool) {
-
+	nbytes int, private protos.ProtocolData) (priv protos.ProtocolData, drop bool,
+) {
 	defer logp.Recover("GapInStream(thrift) exception")
 	logp.Debug("thriftdetailed", "GapInStream called")
 
diff --git a/packetbeat/protos/thrift/thrift_idl.go b/packetbeat/protos/thrift/thrift_idl.go
index 82d8dedbe93..8bc8bec5b3b 100644
--- a/packetbeat/protos/thrift/thrift_idl.go
+++ b/packetbeat/protos/thrift/thrift_idl.go
@@ -49,7 +49,7 @@ func fieldsToArrayByID(fields []*parser.Field) []*string {
 		}
 	}
 
-	output := make([]*string, max+1, max+1)
+	output := make([]*string, max+1)
 
 	for _, field := range fields {
 		if len(field.Name) > 0 {
diff --git a/packetbeat/protos/thrift/thrift_test.go b/packetbeat/protos/thrift/thrift_test.go
index b5377eb4665..0938c60a3be 100644
--- a/packetbeat/protos/thrift/thrift_test.go
+++ b/packetbeat/protos/thrift/thrift_test.go
@@ -122,7 +122,6 @@ func TestThrift_readMessageBegin(t *testing.T) {
 
 	data, _ = hex.DecodeString("800100010000000570696e6700000001")
 	stream = thriftStream{data: data, message: new(thriftMessage)}
-	m = stream.message
 	ok, complete = thrift.readMessageBegin(&stream)
 	if !ok || complete {
 		t.Errorf("Bad result: %v %v", ok, complete)
@@ -130,7 +129,6 @@ func TestThrift_readMessageBegin(t *testing.T) {
 
 	data, _ = hex.DecodeString("800100010000000570696e6700000001")
 	stream = thriftStream{data: data, message: new(thriftMessage)}
-	m = stream.message
 	ok, complete = thrift.readMessageBegin(&stream)
 	if !ok || complete {
 		t.Errorf("Bad result: %v %v", ok, complete)
@@ -150,7 +148,6 @@ func TestThrift_readMessageBegin(t *testing.T) {
 
 	data, _ = hex.DecodeString("0000000570696e670100000000")
 	stream = thriftStream{data: data, message: new(thriftMessage)}
-	m = stream.message
 	ok, complete = thrift.readMessageBegin(&stream)
 	if !ok || complete {
 		t.Error("Bad result:", ok, complete)
diff --git a/packetbeat/protos/tls/alerts.go b/packetbeat/protos/tls/alerts.go
index 4713e7e81f6..4da5c7d5b75 100644
--- a/packetbeat/protos/tls/alerts.go
+++ b/packetbeat/protos/tls/alerts.go
@@ -25,8 +25,10 @@ import (
 	"github.com/elastic/beats/v7/libbeat/logp"
 )
 
-type alertSeverity uint8
-type alertCode uint8
+type (
+	alertSeverity uint8
+	alertCode     uint8
+)
 
 type alert struct {
 	severity alertSeverity
@@ -67,9 +69,7 @@ var alertNames = map[alertCode]string{
 	115: "unknown_psk_identity",
 }
 
-var (
-	errRead = errors.New("Buffer read error")
-)
+var errRead = errors.New("Buffer read error")
 
 func (severity alertSeverity) String() string {
 	switch severity {
diff --git a/packetbeat/protos/tls/algos.go b/packetbeat/protos/tls/algos.go
index b3ba6ea1867..8abd7021b67 100644
--- a/packetbeat/protos/tls/algos.go
+++ b/packetbeat/protos/tls/algos.go
@@ -22,11 +22,13 @@ import (
 	"fmt"
 )
 
-type cipherSuite uint16
-type signatureScheme uint16
-type pointsGroup uint16
-type compressionMethod uint8
-type ecPointsFormat uint8
+type (
+	cipherSuite       uint16
+	signatureScheme   uint16
+	pointsGroup       uint16
+	compressionMethod uint8
+	ecPointsFormat    uint8
+)
 
 // from https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4
 var cipherSuites = map[cipherSuite]string{
@@ -440,26 +442,26 @@ var supportedGroups = map[pointsGroup]string{
 }
 
 var signatureSchemes = map[signatureScheme]string{
-	/* RSASSA-PKCS1-v1_5 algorithms */
+	// RSASSA-PKCS1-v1_5 algorithms
 	0x0401: "rsa_pkcs1_sha256",
 	0x0501: "rsa_pkcs1_sha384",
 	0x0601: "rsa_pkcs1_sha512",
 
-	/* ECDSA algorithms */
+	// ECDSA algorithms
 	0x0403: "ecdsa_secp256r1_sha256",
 	0x0503: "ecdsa_secp384r1_sha384",
 	0x0603: "ecdsa_secp521r1_sha512",
 
-	/* RSASSA-PSS algorithms */
+	// RSASSA-PSS algorithms
 	0x0804: "rsa_pss_sha256",
 	0x0805: "rsa_pss_sha384",
 	0x0806: "rsa_pss_sha512",
 
-	/* EdDSA algorithms */
+	// EdDSA algorithms
 	0x0807: "ed25519",
 	0x0808: "ed448",
 
-	/* Legacy algorithms */
+	// Legacy algorithms
 	0x0201: "rsa_pkcs1_sha1",
 	0x0203: "ecdsa_sha1",
 }
diff --git a/packetbeat/protos/tls/config.go b/packetbeat/protos/tls/config.go
index 775a8f69cc1..2190ccc18dd 100644
--- a/packetbeat/protos/tls/config.go
+++ b/packetbeat/protos/tls/config.go
@@ -30,13 +30,11 @@ type tlsConfig struct {
 	Fingerprints           []string `config:"fingerprints"`
 }
 
-var (
-	defaultConfig = tlsConfig{
-		ProtocolCommon: config.ProtocolCommon{
-			TransactionTimeout: protos.DefaultTransactionExpiration,
-		},
-		SendCertificates:      true,
-		IncludeDetailedFields: true,
-		Fingerprints:          []string{"sha1"},
-	}
-)
+var defaultConfig = tlsConfig{
+	ProtocolCommon: config.ProtocolCommon{
+		TransactionTimeout: protos.DefaultTransactionExpiration,
+	},
+	SendCertificates:      true,
+	IncludeDetailedFields: true,
+	Fingerprints:          []string{"sha1"},
+}
diff --git a/packetbeat/protos/tls/extensions.go b/packetbeat/protos/tls/extensions.go
index 0021705c7f7..1ffceb3c235 100644
--- a/packetbeat/protos/tls/extensions.go
+++ b/packetbeat/protos/tls/extensions.go
@@ -35,12 +35,14 @@ type Extensions struct {
 	InOrder []ExtensionID
 }
 
-type extensionParser func(reader bufferView) interface{}
-type extension struct {
-	label   string
-	parser  extensionParser
-	saveRaw bool
-}
+type (
+	extensionParser func(reader bufferView) interface{}
+	extension       struct {
+		label   string
+		parser  extensionParser
+		saveRaw bool
+	}
+)
 
 const (
 	// ExtensionSupportedGroups identifies the supported group extension
@@ -72,7 +74,6 @@ var extensionMap = map[uint16]extension{
 
 // ParseExtensions returns an Extensions object parsed from the supplied buffer
 func ParseExtensions(buffer bufferView) Extensions {
-
 	var extensionsLength uint16
 	if !buffer.read16Net(0, &extensionsLength) || extensionsLength == 0 {
 		// No extensions
diff --git a/packetbeat/protos/tls/extensions_test.go b/packetbeat/protos/tls/extensions_test.go
index 23caec09019..c61937411a9 100644
--- a/packetbeat/protos/tls/extensions_test.go
+++ b/packetbeat/protos/tls/extensions_test.go
@@ -27,7 +27,6 @@ import (
 )
 
 func TestSni(t *testing.T) {
-
 	// Single element
 
 	buf := mkBuf(t, "000d"+ // 13 bytes
@@ -126,7 +125,6 @@ func TestSni(t *testing.T) {
 }
 
 func TestParseMaxFragmentLength(t *testing.T) {
-
 	r := parseMaxFragmentLen(*mkBuf(t, "01", 1))
 	assert.Equal(t, "2^9", r.(string))
 	r = parseMaxFragmentLen(*mkBuf(t, "04", 1))
diff --git a/packetbeat/protos/tls/fingerprint.go b/packetbeat/protos/tls/fingerprint.go
index 8768ff448e7..70489b687f9 100644
--- a/packetbeat/protos/tls/fingerprint.go
+++ b/packetbeat/protos/tls/fingerprint.go
@@ -36,8 +36,10 @@ type FingerprintAlgorithm struct {
 	algo AlgorithmFactory
 }
 
-var hashMap = make(map[string]*FingerprintAlgorithm)
-var hashNames []string
+var (
+	hashMap   = make(map[string]*FingerprintAlgorithm)
+	hashNames []string
+)
 
 func init() {
 	registerAlgo(func() hash.Hash { return md5.New() }, "md5", "")
diff --git a/packetbeat/protos/tls/ja3.go b/packetbeat/protos/tls/ja3.go
index 6e6faf5e26c..09a0aec5ea4 100644
--- a/packetbeat/protos/tls/ja3.go
+++ b/packetbeat/protos/tls/ja3.go
@@ -25,7 +25,6 @@ import (
 )
 
 func getJa3Fingerprint(hello *helloMessage) (hash string, ja3str string) {
-
 	// build the array of arrays of numbers
 
 	data := make([][]uint16, 5)
diff --git a/packetbeat/protos/tls/parse.go b/packetbeat/protos/tls/parse.go
index d0ec3be75ef..fa4515e2248 100644
--- a/packetbeat/protos/tls/parse.go
+++ b/packetbeat/protos/tls/parse.go
@@ -54,9 +54,9 @@ type recordType uint8
 
 const (
 	recordTypeChangeCipherSpec recordType = 20
-	recordTypeAlert                       = 21
-	recordTypeHandshake                   = 22
-	recordTypeApplicationData             = 23
+	recordTypeAlert            recordType = 21
+	recordTypeHandshake        recordType = 22
+	recordTypeApplicationData  recordType = 23
 )
 
 type handshakeType uint8
@@ -169,8 +169,10 @@ func readHandshakeHeader(buf *streambuf.Buffer) (*handshakeHeader, error) {
 	if len16, err = buf.ReadNetUint16At(2); err != nil {
 		return nil, err
 	}
-	return &handshakeHeader{handshakeType(typ),
-		int(len16) | (int(len8) << 16)}, nil
+	return &handshakeHeader{
+		handshakeType(typ),
+		int(len16) | (int(len8) << 16),
+	}, nil
 }
 
 func (header *recordHeader) String() string {
@@ -215,7 +217,6 @@ func (hello *helloMessage) supportedCiphers() []string {
 }
 
 func (parser *parser) parse(buf *streambuf.Buffer) parserResult {
-
 	for buf.Avail(recordHeaderSize) {
 
 		header, err := readRecordHeader(buf)
diff --git a/packetbeat/protos/tls/parse_test.go b/packetbeat/protos/tls/parse_test.go
index 37f4a1b1956..f599b30c44c 100644
--- a/packetbeat/protos/tls/parse_test.go
+++ b/packetbeat/protos/tls/parse_test.go
@@ -125,12 +125,6 @@ func mapGet(t *testing.T, m common.MapStr, key string) interface{} {
 	return value
 }
 
-func mapInt(t *testing.T, m common.MapStr, key string) uint32 {
-	value, err := m.GetValue(key)
-	assert.NoError(t, err)
-	return value.(uint32)
-}
-
 func TestParseRecordHeader(t *testing.T) {
 	if testing.Verbose() {
 		isDebug = true
@@ -173,6 +167,7 @@ func TestParseHandshakeHeader(t *testing.T) {
 	_, err = readHandshakeHeader(sBuf(t, "112233"))
 	assert.Error(t, err)
 	header, err := readHandshakeHeader(sBuf(t, "11223344"))
+	assert.NoError(t, err)
 	assert.Equal(t, handshakeType(0x11), header.handshakeType)
 	assert.Equal(t, 0x223344, header.length)
 }
@@ -202,7 +197,6 @@ func TestParserParse(t *testing.T) {
 	// Certificate request
 	assert.Equal(t, resultOK, parser.parse(sBuf(t, "16030300040d000000")))
 	assert.True(t, parser.certRequested)
-
 }
 
 func TestParserHello(t *testing.T) {
diff --git a/packetbeat/protos/tls/tls.go b/packetbeat/protos/tls/tls.go
index 9db2a28f694..a785d101021 100644
--- a/packetbeat/protos/tls/tls.go
+++ b/packetbeat/protos/tls/tls.go
@@ -170,10 +170,9 @@ func (plugin *tlsPlugin) doParse(
 	tcptuple *common.TCPTuple,
 	dir uint8,
 ) *tlsConnectionData {
-
 	// Ignore further traffic after the handshake is completed (encrypted connection)
 	// TODO: request/response analysis
-	if 0 != conn.handshakeCompleted&(1<<dir) {
+	if conn.handshakeCompleted&(1<<dir) != 0 {
 		return conn
 	}
 
@@ -229,8 +228,8 @@ func newStream(tcptuple *common.TCPTuple) *stream {
 }
 
 func (plugin *tlsPlugin) ReceivedFin(tcptuple *common.TCPTuple, dir uint8,
-	private protos.ProtocolData) protos.ProtocolData {
-
+	private protos.ProtocolData,
+) protos.ProtocolData {
 	if conn := ensureTLSConnection(private); conn != nil {
 		plugin.sendEvent(conn)
 	}
diff --git a/packetbeat/protos/tls/tls_test.go b/packetbeat/protos/tls/tls_test.go
index 6f84675ba29..5ad963860f8 100644
--- a/packetbeat/protos/tls/tls_test.go
+++ b/packetbeat/protos/tls/tls_test.go
@@ -325,6 +325,7 @@ func TestCompletedHandshake(t *testing.T) {
 
 	// Then a change cypher spec message
 	reqData, err = hex.DecodeString(rawChangeCipherSpec)
+	assert.NoError(t, err)
 	req = protos.Packet{Payload: reqData}
 	private = tls.Parse(&req, tcpTuple, 0, private)
 	assert.NotNil(t, private)
@@ -393,6 +394,7 @@ func TestTLS13VersionNegotiation(t *testing.T) {
 			"9a75ab618828f1b9e418d168130100002e00330024001d002070b27700b360aa" +
 			"3941a22da86901c00e174dc3d83e13cf4159b34b3de6809372002b0002030414" +
 			"0303000101")
+	assert.NoError(t, err)
 	req = protos.Packet{Payload: reqData}
 	private = tls.Parse(&req, tcpTuple, 1, private)
 	assert.NotNil(t, private)
@@ -400,6 +402,7 @@ func TestTLS13VersionNegotiation(t *testing.T) {
 
 	// Then a change cypher spec from the client
 	reqData, err = hex.DecodeString(rawChangeCipherSpec)
+	assert.NoError(t, err)
 	req = protos.Packet{Payload: reqData}
 	private = tls.Parse(&req, tcpTuple, 0, private)
 	assert.NotNil(t, private)
@@ -432,6 +435,7 @@ func TestLegacyVersionNegotiation(t *testing.T) {
 
 	// Then a server hello + change cypher spec
 	reqData, err = hex.DecodeString(rawServerHello + rawChangeCipherSpec)
+	assert.NoError(t, err)
 	req = protos.Packet{Payload: reqData}
 	private = tls.Parse(&req, tcpTuple, 1, private)
 	assert.NotNil(t, private)
@@ -439,6 +443,7 @@ func TestLegacyVersionNegotiation(t *testing.T) {
 
 	// Then a change cypher spec from the client
 	reqData, err = hex.DecodeString(rawChangeCipherSpec)
+	assert.NoError(t, err)
 	req = protos.Packet{Payload: reqData}
 	private = tls.Parse(&req, tcpTuple, 0, private)
 	assert.NotNil(t, private)
diff --git a/packetbeat/protos/udp/udp.go b/packetbeat/protos/udp/udp.go
index 1d26fbf0c87..99a267cf512 100644
--- a/packetbeat/protos/udp/udp.go
+++ b/packetbeat/protos/udp/udp.go
@@ -81,7 +81,7 @@ func (udp *UDP) Process(id *flows.FlowID, pkt *protos.Packet) {
 // any two UdpProtocolPlugins operate on the same port number then an error
 // will be returned.
 func buildPortsMap(plugins map[protos.Protocol]protos.UDPPlugin) (map[uint16]protos.Protocol, error) {
-	var res = map[uint16]protos.Protocol{}
+	res := map[uint16]protos.Protocol{}
 
 	for proto, protoPlugin := range plugins {
 		for _, port := range protoPlugin.GetPorts() {
diff --git a/packetbeat/protos/udp/udp_test.go b/packetbeat/protos/udp/udp_test.go
index 998bf071638..3de61b2efae 100644
--- a/packetbeat/protos/udp/udp_test.go
+++ b/packetbeat/protos/udp/udp_test.go
@@ -77,9 +77,7 @@ func (p TestProtocols) GetAllUDP() map[protos.Protocol]protos.UDPPlugin {
 	return p.udp
 }
 
-func (p TestProtocols) Register(proto protos.Protocol, plugin protos.Plugin) {
-	return
-}
+func (p TestProtocols) Register(proto protos.Protocol, plugin protos.Plugin) {}
 
 type TestProtocol struct {
 	Ports []int          // Ports that the protocol operates on.
diff --git a/packetbeat/publish/publish.go b/packetbeat/publish/publish.go
index e4e393d8da8..f754dd8c545 100644
--- a/packetbeat/publish/publish.go
+++ b/packetbeat/publish/publish.go
@@ -84,7 +84,6 @@ func (p *TransactionPublisher) Stop() {
 func (p *TransactionPublisher) CreateReporter(
 	config *common.Config,
 ) (func(beat.Event), error) {
-
 	// load and register the module it's fields, tags and processors settings
 	meta := struct {
 		Index      string                  `config:"index"`
diff --git a/packetbeat/publish/publish_test.go b/packetbeat/publish/publish_test.go
index 64b2c777dc2..98b5dfc91e3 100644
--- a/packetbeat/publish/publish_test.go
+++ b/packetbeat/publish/publish_test.go
@@ -47,7 +47,7 @@ func testEvent() beat.Event {
 // Test that FilterEvent detects events that do not contain the required fields
 // and returns error.
 func TestFilterEvent(t *testing.T) {
-	var testCases = []struct {
+	testCases := []struct {
 		f   func() beat.Event
 		err string
 	}{
@@ -93,7 +93,7 @@ func TestFilterEvent(t *testing.T) {
 }
 
 func TestPublish(t *testing.T) {
-	var srcIP, dstIP = "192.145.2.4", "192.145.2.5"
+	srcIP, dstIP := "192.145.2.4", "192.145.2.5"
 
 	event := func() *beat.Event {
 		return &beat.Event{
diff --git a/packetbeat/scripts/mage/package.go b/packetbeat/scripts/mage/package.go
index fe5e55bb305..55f26493cf5 100644
--- a/packetbeat/scripts/mage/package.go
+++ b/packetbeat/scripts/mage/package.go
@@ -28,7 +28,7 @@ import (
 func CustomizePackaging() {
 	var (
 		configYml = devtools.PackageFile{
-			Mode:   0600,
+			Mode:   0o600,
 			Source: "{{.PackageDir}}/{{.BeatName}}.yml",
 			Config: true,
 			Dep: func(spec devtools.PackageSpec) error {
@@ -39,7 +39,7 @@ func CustomizePackaging() {
 			},
 		}
 		referenceConfigYml = devtools.PackageFile{
-			Mode:   0644,
+			Mode:   0o644,
 			Source: "{{.PackageDir}}/{{.BeatName}}.reference.yml",
 			Dep: func(spec devtools.PackageSpec) error {
 				c := ConfigFileParams()
diff --git a/packetbeat/sniffer/afpacket.go b/packetbeat/sniffer/afpacket.go
index 10efaede42e..eac8240219c 100644
--- a/packetbeat/sniffer/afpacket.go
+++ b/packetbeat/sniffer/afpacket.go
@@ -24,8 +24,8 @@ import "fmt"
 // The restriction is that the block_size must be divisible by both the
 // frame size and page size.
 func afpacketComputeSize(targetSizeMb int, snaplen int, pageSize int) (
-	frameSize int, blockSize int, numBlocks int, err error) {
-
+	frameSize int, blockSize int, numBlocks int, err error,
+) {
 	if snaplen < pageSize {
 		frameSize = pageSize / (pageSize / snaplen)
 	} else {
diff --git a/packetbeat/sniffer/afpacket_linux.go b/packetbeat/sniffer/afpacket_linux.go
index 7976ace838a..5d4c60c5313 100644
--- a/packetbeat/sniffer/afpacket_linux.go
+++ b/packetbeat/sniffer/afpacket_linux.go
@@ -41,8 +41,8 @@ type afpacketHandle struct {
 }
 
 func newAfpacketHandle(device string, snaplen int, block_size int, num_blocks int,
-	timeout time.Duration, autoPromiscMode bool) (*afpacketHandle, error) {
-
+	timeout time.Duration, autoPromiscMode bool) (*afpacketHandle, error,
+) {
 	var err error
 	var promiscEnabled bool
 
diff --git a/packetbeat/sniffer/afpacket_nonlinux.go b/packetbeat/sniffer/afpacket_nonlinux.go
index 861e55fe1e5..67e32e9b267 100644
--- a/packetbeat/sniffer/afpacket_nonlinux.go
+++ b/packetbeat/sniffer/afpacket_nonlinux.go
@@ -28,12 +28,11 @@ import (
 	"github.com/tsg/gopacket/layers"
 )
 
-type afpacketHandle struct {
-}
+type afpacketHandle struct{}
 
 func newAfpacketHandle(device string, snaplen int, blockSize int, numBlocks int,
-	timeout time.Duration, enableAutoPromiscMode bool) (*afpacketHandle, error) {
-
+	timeout time.Duration, enableAutoPromiscMode bool) (*afpacketHandle, error,
+) {
 	return nil, fmt.Errorf("Afpacket MMAP sniffing is only available on Linux")
 }
 
diff --git a/packetbeat/sniffer/device.go b/packetbeat/sniffer/device.go
index 52ff220309d..fbe23d5ce2c 100644
--- a/packetbeat/sniffer/device.go
+++ b/packetbeat/sniffer/device.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"runtime"
 	"strconv"
+	"strings"
 
 	"github.com/tsg/gopacket/pcap"
 
@@ -33,44 +34,49 @@ var deviceAnySupported = runtime.GOOS == "linux"
 // this computer. If the withDescription parameter is set to true, a human
 // readable version of the adapter name is added. If the withIP parameter
 // is set to true, IP address of the adapter is added.
-func ListDeviceNames(withDescription bool, withIP bool) ([]string, error) {
+func ListDeviceNames(withDescription, withIP bool) ([]string, error) {
 	devices, err := pcap.FindAllDevs()
 	if err != nil {
-		return []string{}, err
+		return nil, err
 	}
+	return formatDeviceNames(devices, withDescription, withIP), nil
+}
 
-	ret := []string{}
+func formatDeviceNames(devices []pcap.Interface, withDescription, withIP bool) []string {
+	if len(devices) == 0 {
+		return nil
+	}
+	names := make([]string, 0, len(devices))
+	var buf strings.Builder
 	for _, dev := range devices {
-		r := dev.Name
+		buf.Reset()
+		buf.WriteString(dev.Name)
 
 		if withDescription {
 			desc := "No description available"
 			if len(dev.Description) > 0 {
 				desc = dev.Description
 			}
-			r += fmt.Sprintf(" (%s)", desc)
+			fmt.Fprintf(&buf, " (%s)", desc)
 		}
 
 		if withIP {
-			ips := "Not assigned ip address"
-			if len(dev.Addresses) > 0 {
-				ips = ""
-
+			buf.WriteString(" (")
+			if len(dev.Addresses) == 0 {
+				buf.WriteString("Not assigned ip address")
+			} else {
 				for i, address := range []pcap.InterfaceAddress(dev.Addresses) {
-					// Add a space between the IP address.
-					if i > 0 {
-						ips += " "
+					if i != 0 {
+						buf.WriteByte(' ')
 					}
-
-					ips += fmt.Sprintf("%s", address.IP.String())
+					fmt.Fprint(&buf, address.IP)
 				}
 			}
-			r += fmt.Sprintf(" (%s)", ips)
-
+			buf.WriteByte(')')
 		}
-		ret = append(ret, r)
+		names = append(names, buf.String())
 	}
-	return ret, nil
+	return names
 }
 
 func resolveDeviceName(name string) (string, error) {
diff --git a/packetbeat/sniffer/device_test.go b/packetbeat/sniffer/device_test.go
new file mode 100644
index 00000000000..189bc92a9cd
--- /dev/null
+++ b/packetbeat/sniffer/device_test.go
@@ -0,0 +1,136 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package sniffer
+
+import (
+	"net"
+	"reflect"
+	"testing"
+
+	"github.com/tsg/gopacket/pcap"
+)
+
+var formatDeviceNamesTests = []struct {
+	name       string
+	interfaces []pcap.Interface
+	withDesc   bool
+	withIP     bool
+	want       []string
+}{
+	{name: "empty"},
+	{
+		name: "loopback no withs",
+		interfaces: []pcap.Interface{
+			{
+				Name: "lo", Description: "loopback",
+				Addresses: []pcap.InterfaceAddress{
+					{IP: net.IP{127, 0, 0, 1}, Netmask: net.IPMask{255, 0, 0, 0}},
+				},
+			},
+		},
+		want: []string{
+			"lo",
+		},
+	},
+	{
+		name: "loopback with desc",
+		interfaces: []pcap.Interface{
+			{
+				Name: "lo", Description: "loopback",
+				Addresses: []pcap.InterfaceAddress{
+					{IP: net.IP{127, 0, 0, 1}, Netmask: net.IPMask{255, 0, 0, 0}},
+				},
+			},
+		},
+		withDesc: true,
+		want: []string{
+			"lo (loopback)",
+		},
+	},
+	{
+		name: "loopback with IPs",
+		interfaces: []pcap.Interface{
+			{
+				Name: "lo", Description: "loopback",
+				Addresses: []pcap.InterfaceAddress{
+					{IP: net.IP{127, 0, 0, 1}, Netmask: net.IPMask{255, 0, 0, 0}},
+				},
+			},
+		},
+		withIP: true,
+		want: []string{
+			"lo (127.0.0.1)",
+		},
+	},
+	{
+		name: "loopback with the lot",
+		interfaces: []pcap.Interface{
+			{
+				Name: "lo", Description: "loopback",
+				Addresses: []pcap.InterfaceAddress{
+					{IP: net.IP{127, 0, 0, 1}, Netmask: net.IPMask{255, 0, 0, 0}},
+				},
+			},
+		},
+		withDesc: true,
+		withIP:   true,
+		want: []string{
+			"lo (loopback) (127.0.0.1)",
+		},
+	},
+	{
+		name: "two addr loopback with the lot",
+		interfaces: []pcap.Interface{
+			{
+				Name: "lo", Description: "loopback",
+				Addresses: []pcap.InterfaceAddress{
+					{IP: net.IP{127, 0, 0, 1}, Netmask: net.IPMask{255, 0, 0, 0}},
+					{IP: net.IP{127, 0, 1, 1}, Netmask: net.IPMask{255, 0, 0, 0}},
+				},
+			},
+		},
+		withDesc: true,
+		withIP:   true,
+		want: []string{
+			"lo (loopback) (127.0.0.1 127.0.1.1)",
+		},
+	},
+	{
+		name: "no IP loopback with the lot",
+		interfaces: []pcap.Interface{
+			{
+				Name: "lo", Description: "loopback",
+			},
+		},
+		withDesc: true,
+		withIP:   true,
+		want: []string{
+			"lo (loopback) (Not assigned ip address)",
+		},
+	},
+}
+
+func TestFormatDevices(t *testing.T) {
+	for _, test := range formatDeviceNamesTests {
+		got := formatDeviceNames(test.interfaces, test.withDesc, test.withIP)
+		if !reflect.DeepEqual(got, test.want) {
+			t.Errorf("unexpected result for test %s:\ngot: %v\nwant:%v",
+				test.name, got, test.want)
+		}
+	}
+}
diff --git a/packetbeat/sniffer/sniffer.go b/packetbeat/sniffer/sniffer.go
index bfe720c7b98..07a7e3096a9 100644
--- a/packetbeat/sniffer/sniffer.go
+++ b/packetbeat/sniffer/sniffer.go
@@ -39,7 +39,6 @@ import (
 // to a Worker.
 type Sniffer struct {
 	config config.InterfacesConfig
-	dumper *pcap.Dumper
 
 	state atomic.Int32 // store snifferState
 
@@ -60,7 +59,6 @@ type Worker interface {
 
 type snifferHandle interface {
 	gopacket.PacketDataSource
-
 	LinkType() layers.LinkType
 	Close()
 }
diff --git a/packetbeat/sniffer/sniffer_test.go b/packetbeat/sniffer/sniffer_test.go
index eea7821d889..52b0b57fb33 100644
--- a/packetbeat/sniffer/sniffer_test.go
+++ b/packetbeat/sniffer/sniffer_test.go
@@ -52,13 +52,16 @@ func TestSniffer_afpacketComputeSize(t *testing.T) {
 		t.Error("Value too big", blockSize, numBlocks)
 	}
 
-	frameSize, blockSize, numBlocks, err = afpacketComputeSize(0, 1514, 4096)
+	_, _, _, err = afpacketComputeSize(0, 1514, 4096)
 	if err == nil {
 		t.Error("Expected an error")
 	}
 
 	// 16436 is the default MTU size of the loopback interface
 	frameSize, blockSize, numBlocks, err = afpacketComputeSize(30, 16436, 4096)
+	if err != nil {
+		t.Error(err)
+	}
 	if frameSize != 4096*5 || blockSize != 4096*5*128 || numBlocks != 12 {
 		t.Error("Bad result", frameSize, blockSize, numBlocks)
 	}