[Metricbeat][Kubernetes] Extend state_node with more conditions

CHANGELOG.next.asciidoc

@@ -126,6 +126,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - kubernetes.container.cpu.limit.cores and kubernetes.container.cpu.requests.cores are now floats. {issue}11975[11975]
 - Change types of numeric metrics from Kubelet summary api to double so as to cover big numbers. {pull}23335[23335]
 - Add container.image.name and containe.name ECS fields for state_container. {pull}23802[23802]
+- Add support for the MemoryPressure, DiskPressure, OutOfDisk and PIDPressure status conditions in state_node. {pull}[23905]
 
 *Packetbeat*
 

metricbeat/docs/fields.asciidoc

@@ -29807,6 +29807,46 @@ type: keyword
 Node unschedulable status
 
 
+type: boolean
+
+--
+
+*`kubernetes.node.status.memory_pressure`*::
++
+--
+Node MemoryPressure status
+
+
+type: boolean
+
+--
+
+*`kubernetes.node.status.disk_pressure`*::
++
+--
+Node DiskPressure status
+
+
+type: boolean
+
+--
+
+*`kubernetes.node.status.out_of_disk`*::
++
+--
+Node OutOfDisk status
+
+
+type: boolean
+
+--
+
+*`kubernetes.node.status.pid_pressure`*::
++
+--
+Node PIDPressure status
+
+
 type: boolean
 
 --
@@ -30774,7 +30814,7 @@ type: long
 *`linux.conntrack.summary.insert_failed`*::
 +
 --
-Number of entries where list insert insert failed 
+Number of entries where list insert insert failed
 
 
 type: long
@@ -40402,7 +40442,7 @@ format: bytes
 *`redis.info.memory.used.lua`*::
 +
 --
-Used memory by the Lua engine.        
+Used memory by the Lua engine.
 
 
 type: long
@@ -40414,7 +40454,7 @@ format: bytes
 *`redis.info.memory.used.dataset`*::
 +
 --
-The size in bytes of the dataset 
+The size in bytes of the dataset
 
 
 type: long
@@ -40659,7 +40699,7 @@ format: duration
 *`redis.info.persistence.rdb.copy_on_write.last_size`*::
 +
 --
-The size in bytes of copy-on-write allocations during the last RBD save operation                
+The size in bytes of copy-on-write allocations during the last RBD save operation
 
 
 type: long
@@ -40788,7 +40828,7 @@ format: bytes
 *`redis.info.persistence.aof.size.current`*::
 +
 --
-AOF current file size             
+AOF current file size
 
 
 type: long
@@ -40894,7 +40934,7 @@ format: bytes
 *`redis.info.replication.backlog.first_byte_offset`*::
 +
 --
-The master offset of the replication backlog buffer          
+The master offset of the replication backlog buffer
 
 
 type: long
@@ -44559,7 +44599,7 @@ type: keyword
 *`system.raid.sync_action`*::
 +
 --
-Current sync action, if the RAID array is redundant 
+Current sync action, if the RAID array is redundant
 
 
 type: keyword
@@ -45000,7 +45040,7 @@ All TCP connections
 *`system.socket.summary.tcp.memory`*::
 +
 --
-Memory used by TCP sockets in bytes, based on number of allocated pages and system page size. Corresponds to limits set in /proc/sys/net/ipv4/tcp_mem. Only available on Linux. 
+Memory used by TCP sockets in bytes, based on number of allocated pages and system page size. Corresponds to limits set in /proc/sys/net/ipv4/tcp_mem. Only available on Linux.
 
 
 type: integer
@@ -45146,7 +45186,7 @@ All UDP connections
 *`system.socket.summary.udp.memory`*::
 +
 --
-Memory used by UDP sockets in bytes, based on number of allocated pages and system page size. Corresponds to limits set in /proc/sys/net/ipv4/udp_mem. Only available on Linux. 
+Memory used by UDP sockets in bytes, based on number of allocated pages and system page size. Corresponds to limits set in /proc/sys/net/ipv4/udp_mem. Only available on Linux.
 
 
 type: integer
@@ -46837,4 +46877,3 @@ Epoch value of the Zookeeper transaction ID. An epoch signifies the period in wh
 type: long
 
 --
-

metricbeat/helper/prometheus/metric.go

@@ -79,10 +79,11 @@ type MetricOption interface {
 	Process(field string, value interface{}, labels common.MapStr) (string, interface{}, common.MapStr)
 }
 
-// OpFilter only processes metrics matching the given filter
-func OpFilter(filter map[string]string) MetricOption {
-	return opFilter{
-		labels: filter,
+// OpFilterMap only processes metrics matching the given filter
+func OpFilterMap(label string, filterMap map[string]string) MetricOption {
+	return opFilterMap{
+		label:     label,
+		filterMap: filterMap,
 	}
 }
 
@@ -331,18 +332,22 @@ func (m *infoMetric) GetField() string {
 	return ""
 }
 
-type opFilter struct {
-	labels map[string]string
+type opFilterMap struct {
+	label     string
+	filterMap map[string]string
 }
 
-// Process will return nil if labels don't match the filter
-func (o opFilter) Process(field string, value interface{}, labels common.MapStr) (string, interface{}, common.MapStr) {
-	for k, v := range o.labels {
-		if labels[k] != v {
-			return "", nil, nil
+// Called by the Prometheus helper to apply extra options on retrieved metrics
+// Check whether the value of the specified label is allowed and, if yes, return the metric via the specified mapped field
+// Else, if the specified label does not match the filter, return nil
+// This is useful in cases where multiple Metricbeat fields need to be defined per Prometheus metric, based on label values
+func (o opFilterMap) Process(field string, value interface{}, labels common.MapStr) (string, interface{}, common.MapStr) {
+	for k, v := range o.filterMap {
+		if labels[o.label] == k {
+			return fmt.Sprintf("%v.%v", field, v), value, labels
 		}
 	}
-	return field, value, labels
+	return "", nil, nil
 }
 
 type opLowercaseValue struct{}

metricbeat/helper/prometheus/prometheus_test.go

@@ -397,9 +397,36 @@ func TestPrometheus(t *testing.T) {
 			msg: "Label metrics, filter",
 			mapping: &MetricsMapping{
 				Metrics: map[string]MetricMap{
-					"first_metric": LabelMetric("first.metric", "label4", OpLowercaseValue(), OpFilter(map[string]string{
-						"foo": "filtered",
-					})),
+					"first_metric": LabelMetric("first.metric", "label4", OpFilterMap(
+						"label1",
+						map[string]string{"value1": "foo"},
+					)),
+				},
+				Labels: map[string]LabelMap{
+					"label1": Label("labels.label1"),
+				},
+			},
+			expected: []common.MapStr{
+				common.MapStr{
+					"first": common.MapStr{
+						"metric": common.MapStr{
+							"foo": "FOO",
+						},
+					},
+					"labels": common.MapStr{
+						"label1": "value1",
+					},
+				},
+			},
+		},
+		{
+			msg: "Label metrics, filter",
+			mapping: &MetricsMapping{
+				Metrics: map[string]MetricMap{
+					"first_metric": LabelMetric("first.metric", "label4", OpLowercaseValue(), OpFilterMap(
+						"foo",
+						map[string]string{"Filtered": "filtered"},
+					)),
 				},
 				Labels: map[string]LabelMap{
 					"label1": Label("labels.label1"),