feat: add logger

.gitignore

@@ -0,0 +1,2 @@
+./vscode
+./idea

core/resolver.go

@@ -8,11 +8,12 @@ import (
 	"net"
 	"strings"
 
+	"github.com/kehiy/dns-server/logger"
 	"golang.org/x/net/dns/dnsmessage"
 )
 
-const ROOTSERVERS = `198.41.0.4,199.9.14.201,192.33.4.12,199.7.91.13,192.203.230.10,192.5.5.241,
-	192.112.36.4,198.97.190.53`
+const ROOTSERVERS = `198.41.0.4,199.9.14.201,192.33.4.12,199.7.91.13,
+					 192.203.230.10,192.5.5.241,192.112.36.4,198.97.190.53`
 
 func HandlePacket(pc net.PacketConn, addr net.Addr, buf []byte) {
 	//* send incoming packets to handlePacket function
@@ -122,7 +123,7 @@ func dnsQuery(servers []net.IP, question dnsmessage.Question) (*dnsmessage.Messa
 							Type: dnsmessage.TypeA, Class: dnsmessage.ClassINET,
 						})
 					if err != nil {
-						fmt.Printf("warning: lookup of nameserver %s failed: %err\n", nameserver, err)
+						logger.Warn("lookup of nameserver failed", "nameserver", nameserver, "error", err)
 					} else {
 						newResolverServersFound = true
 						for _, answer := range response.Answers {

go.mod

@@ -2,4 +2,20 @@ module github.com/kehiy/dns-server
 
 go 1.20
 
-require golang.org/x/net v0.10.0
+require (
+	github.com/rs/zerolog v1.30.0
+	golang.org/x/net v0.10.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+require (
+	github.com/mattn/go-colorable v0.1.12 // indirect
+	github.com/mattn/go-isatty v0.0.14 // indirect
+	github.com/stretchr/testify v1.8.4
+	golang.org/x/sys v0.8.0 // indirect
+)

go.sum

@@ -1,2 +1,25 @@
+github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/mattn/go-colorable v0.1.12 h1:jF+Du6AlPIjs2BiUiQlKOX0rt3SujHxPnksPKZbaA40=
+github.com/mattn/go-colorable v0.1.12/go.mod h1:u5H1YNBxpqRaxsYJYSkiCWKzEfiAb1Gb520KVy5xxl4=
+github.com/mattn/go-isatty v0.0.14 h1:yVuAays6BHfxijgZPzw+3Zlu5yQgKGP2/hcQbHb7S9Y=
+github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
+github.com/rs/zerolog v1.30.0 h1:SymVODrcRsaRaSInD9yQtKbtWqwsfoPcRff/oRXLj4c=
+github.com/rs/zerolog v1.30.0/go.mod h1:/tk+P47gFdPXq4QYjvCmT5/Gsug2nagsFWBWhAiSi1w=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 golang.org/x/net v0.10.0 h1:X2//UzNDwYmtCLn7To6G58Wr6f5ahEAQgKNzv9Y951M=
 golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
+golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

logger/logger.go

@@ -0,0 +1,61 @@
+package logger
+
+import (
+	"encoding/hex"
+	"fmt"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+)
+
+func addFields(event *zerolog.Event, keyvals ...interface{}) *zerolog.Event {
+	if len(keyvals)%2 != 0 {
+		keyvals = append(keyvals, "!MISSING-VALUE!")
+	}
+	for i := 0; i < len(keyvals); i += 2 {
+		key, ok := keyvals[i].(string)
+		if !ok {
+			key = "!INVALID-KEY!"
+		}
+		///
+		switch v := keyvals[i+1].(type) {
+		case fmt.Stringer:
+			event.Stringer(key, v)
+		case error:
+			event.AnErr(key, v)
+		case []byte:
+			event.Str(key, fmt.Sprintf("%v", hex.EncodeToString(v)))
+		default:
+			event.Any(key, v)
+		}
+	}
+	return event
+}
+
+func Trace(msg string, keyvals ...interface{}) {
+	addFields(log.Trace(), keyvals...).Msg(msg)
+}
+
+func Debug(msg string, keyvals ...interface{}) {
+	addFields(log.Debug(), keyvals...).Msg(msg)
+}
+
+func Info(msg string, keyvals ...interface{}) {
+	addFields(log.Info(), keyvals...).Msg(msg)
+}
+
+func Warn(msg string, keyvals ...interface{}) {
+	addFields(log.Warn(), keyvals...).Msg(msg)
+}
+
+func Error(msg string, keyvals ...interface{}) {
+	addFields(log.Error(), keyvals...).Msg(msg)
+}
+
+func Fatal(msg string, keyvals ...interface{}) {
+	addFields(log.Fatal(), keyvals...).Msg(msg)
+}
+
+func Panic(msg string, keyvals ...interface{}) {
+	addFields(log.Panic(), keyvals...).Msg(msg)
+}

logger/logger_test.go

@@ -0,0 +1,42 @@
+package logger
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/rs/zerolog/log"
+	"github.com/stretchr/testify/assert"
+)
+
+type Foo struct{}
+
+func (f Foo) String() string {
+	return "foo"
+}
+
+func TestLogger(t *testing.T) {
+	var buf bytes.Buffer
+	log.Logger = log.Output(&buf)
+
+	Trace("a", "ok", "!ok")
+	Info("b", nil)
+	Info("b", "a", nil)
+	Info("c", "b", []byte{1, 2, 3})
+	Warn("d", "x")
+	Error("e", "y", Foo{})
+
+	out := buf.String()
+
+	fmt.Println(out)
+	assert.Contains(t, out, "foo")
+	assert.Contains(t, out, "010203")
+	assert.Contains(t, out, "!INVALID-KEY!")
+	assert.Contains(t, out, "!MISSING-VALUE!")
+	assert.Contains(t, out, "null")
+	assert.Contains(t, out, "trace")
+	assert.NotContains(t, out, "debug")
+	assert.Contains(t, out, "info")
+	assert.Contains(t, out, "warn")
+	assert.Contains(t, out, "error")
+}

main.go

@@ -1,25 +1,24 @@
 package main
 
 import (
-	"fmt"
-	"log"
 	"net"
 
 	"github.com/kehiy/dns-server/core"
+	"github.com/kehiy/dns-server/logger"
 )
 
 func main() {
 	pc, err := net.ListenPacket("udp", ":53")
 	if err != nil {
-		log.Fatal(err)
+		logger.Panic("can't run the DNS server:", "error", err)
 	}
 	defer pc.Close()
 
 	for {
 		buf := make([]byte, 512)
 		n, addr, err := pc.ReadFrom(buf)
 		if err != nil {
-			fmt.Printf("Connection error [%s]: %s\n", addr.String(), err)
+			logger.Info("read error", "from", addr.String(), "network", addr.Network(), "error", err)
 			continue
 		}
 		go core.HandlePacket(pc, addr, buf[:n])