Merge pull request #11844 from bawhetst/add-pod-container-id

discovery/kubernetes: add container ID as a meta label for pod targets

discovery/kubernetes/pod.go

@@ -183,6 +183,7 @@ const (
 	podNameLabel                  = metaLabelPrefix + "pod_name"
 	podIPLabel                    = metaLabelPrefix + "pod_ip"
 	podContainerNameLabel         = metaLabelPrefix + "pod_container_name"
+	podContainerIDLabel           = metaLabelPrefix + "pod_container_id"
 	podContainerImageLabel        = metaLabelPrefix + "pod_container_image"
 	podContainerPortNameLabel     = metaLabelPrefix + "pod_container_port_name"
 	podContainerPortNumberLabel   = metaLabelPrefix + "pod_container_port_number"
@@ -248,6 +249,24 @@ func podLabels(pod *apiv1.Pod) model.LabelSet {
 	return ls
 }
 
+func (p *Pod) findPodContainerStatus(statuses *[]apiv1.ContainerStatus, containerName string) (*apiv1.ContainerStatus, error) {
+	for _, s := range *statuses {
+		if s.Name == containerName {
+			return &s, nil
+		}
+	}
+	return nil, fmt.Errorf("cannot find container with name %v", containerName)
+}
+
+func (p *Pod) findPodContainerID(statuses *[]apiv1.ContainerStatus, containerName string) string {
+	cStatus, err := p.findPodContainerStatus(statuses, containerName)
+	if err != nil {
+		level.Debug(p.logger).Log("msg", "cannot find container ID", "err", err)
+		return ""
+	}
+	return cStatus.ContainerID
+}
+
 func (p *Pod) buildPod(pod *apiv1.Pod) *targetgroup.Group {
 	tg := &targetgroup.Group{
 		Source: podSource(pod),
@@ -267,6 +286,12 @@ func (p *Pod) buildPod(pod *apiv1.Pod) *targetgroup.Group {
 	for i, c := range containers {
 		isInit := i >= len(pod.Spec.Containers)
 
+		cStatuses := &pod.Status.ContainerStatuses
+		if isInit {
+			cStatuses = &pod.Status.InitContainerStatuses
+		}
+		cID := p.findPodContainerID(cStatuses, c.Name)
+
 		// If no ports are defined for the container, create an anonymous
 		// target per container.
 		if len(c.Ports) == 0 {
@@ -275,6 +300,7 @@ func (p *Pod) buildPod(pod *apiv1.Pod) *targetgroup.Group {
 			tg.Targets = append(tg.Targets, model.LabelSet{
 				model.AddressLabel:     lv(pod.Status.PodIP),
 				podContainerNameLabel:  lv(c.Name),
+				podContainerIDLabel:    lv(cID),
 				podContainerImageLabel: lv(c.Image),
 				podContainerIsInit:     lv(strconv.FormatBool(isInit)),
 			})
@@ -288,6 +314,7 @@ func (p *Pod) buildPod(pod *apiv1.Pod) *targetgroup.Group {
 			tg.Targets = append(tg.Targets, model.LabelSet{
 				model.AddressLabel:            lv(addr),
 				podContainerNameLabel:         lv(c.Name),
+				podContainerIDLabel:           lv(cID),
 				podContainerImageLabel:        lv(c.Image),
 				podContainerPortNumberLabel:   lv(ports),
 				podContainerPortNameLabel:     lv(port.Name),

discovery/kubernetes/pod_test.go

@@ -81,6 +81,16 @@ func makeMultiPortPods() *v1.Pod {
 					Status: v1.ConditionTrue,
 				},
 			},
+			ContainerStatuses: []v1.ContainerStatus{
+				{
+					Name:        "testcontainer0",
+					ContainerID: "docker://a1b2c3d4e5f6",
+				},
+				{
+					Name:        "testcontainer1",
+					ContainerID: "containerd://6f5e4d3c2b1a",
+				},
+			},
 		},
 	}
 }
@@ -118,6 +128,12 @@ func makePods() *v1.Pod {
 					Status: v1.ConditionTrue,
 				},
 			},
+			ContainerStatuses: []v1.ContainerStatus{
+				{
+					Name:        "testcontainer",
+					ContainerID: "docker://a1b2c3d4e5f6",
+				},
+			},
 		},
 	}
 }
@@ -162,6 +178,18 @@ func makeInitContainerPods() *v1.Pod {
 					Status: v1.ConditionFalse,
 				},
 			},
+			ContainerStatuses: []v1.ContainerStatus{
+				{
+					Name:        "testcontainer",
+					ContainerID: "docker://a1b2c3d4e5f6",
+				},
+			},
+			InitContainerStatuses: []v1.ContainerStatus{
+				{
+					Name:        "initcontainer",
+					ContainerID: "containerd://6f5e4d3c2b1a",
+				},
+			},
 		},
 	}
 }
@@ -179,6 +207,7 @@ func expectedPodTargetGroups(ns string) map[string]*targetgroup.Group {
 					"__meta_kubernetes_pod_container_port_number":   "9000",
 					"__meta_kubernetes_pod_container_port_protocol": "TCP",
 					"__meta_kubernetes_pod_container_init":          "false",
+					"__meta_kubernetes_pod_container_id":            "docker://a1b2c3d4e5f6",
 				},
 			},
 			Labels: model.LabelSet{
@@ -230,6 +259,7 @@ func TestPodDiscoveryBeforeRun(t *testing.T) {
 						"__meta_kubernetes_pod_container_port_number":   "9000",
 						"__meta_kubernetes_pod_container_port_protocol": "TCP",
 						"__meta_kubernetes_pod_container_init":          "false",
+						"__meta_kubernetes_pod_container_id":            "docker://a1b2c3d4e5f6",
 					},
 					{
 						"__address__":                                   "1.2.3.4:9001",
@@ -239,12 +269,14 @@ func TestPodDiscoveryBeforeRun(t *testing.T) {
 						"__meta_kubernetes_pod_container_port_number":   "9001",
 						"__meta_kubernetes_pod_container_port_protocol": "UDP",
 						"__meta_kubernetes_pod_container_init":          "false",
+						"__meta_kubernetes_pod_container_id":            "docker://a1b2c3d4e5f6",
 					},
 					{
 						"__address__":                           "1.2.3.4",
 						"__meta_kubernetes_pod_container_name":  "testcontainer1",
 						"__meta_kubernetes_pod_container_image": "testcontainer1:latest",
 						"__meta_kubernetes_pod_container_init":  "false",
+						"__meta_kubernetes_pod_container_id":    "containerd://6f5e4d3c2b1a",
 					},
 				},
 				Labels: model.LabelSet{
@@ -280,6 +312,7 @@ func TestPodDiscoveryInitContainer(t *testing.T) {
 		"__meta_kubernetes_pod_container_name":  "initcontainer",
 		"__meta_kubernetes_pod_container_image": "initcontainer:latest",
 		"__meta_kubernetes_pod_container_init":  "true",
+		"__meta_kubernetes_pod_container_id":    "containerd://6f5e4d3c2b1a",
 	})
 	expected[key].Labels["__meta_kubernetes_pod_phase"] = "Pending"
 	expected[key].Labels["__meta_kubernetes_pod_ready"] = "false"

docs/configuration/configuration.md

@@ -1856,6 +1856,7 @@ Available meta labels:
 * `__meta_kubernetes_pod_annotationpresent_<annotationname>`: `true` for each annotation from the pod object.
 * `__meta_kubernetes_pod_container_init`: `true` if the container is an [InitContainer](https://kubernetes.io/docs/concepts/workloads/pods/init-containers/)
 * `__meta_kubernetes_pod_container_name`: Name of the container the target address points to.
+* `__meta_kubernetes_pod_container_id`: ID of the container the target address points to. The ID is in the form `<type>://<container_id>`.
 * `__meta_kubernetes_pod_container_image`: The image the container is using.
 * `__meta_kubernetes_pod_container_port_name`: Name of the container port.
 * `__meta_kubernetes_pod_container_port_number`: Number of the container port.