fix(receiver/k8s_cluster): Include non-ready containers (open-telemetry#43149)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
This PR fixes an issue where the receiver was ignoring non-ready
containers with an empty ContainerID, resulting in incomplete data
collection for the newly introduced metrics `k8s.container.status.state`
and `k8s.container.status.reason`.
<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes open-telemetry#43147 
<!--Describe what testing was performed and which tests were added.-->
#### Testing
Updated `TestTransform`
<!--Describe the documentation added.-->
#### Documentation
<!--Please delete paragraphs that you did not use before submitting.-->

Author: yurytaranau

.chloggen/k8sclusterreceiver-emtpy-containterid.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: receiver/k8s_cluster
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix for k8sclusterreceiver to handle empty containerID in ContainerStatus
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [43147]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/k8sclusterreceiver/internal/pod/pods.go

@@ -51,9 +51,6 @@ func Transform(pod *corev1.Pod) *corev1.Pod {
 	}
 	for i := range pod.Status.ContainerStatuses {
 		cs := &pod.Status.ContainerStatuses[i]
-		if cs.ContainerID == "" {
-			continue
-		}
 		newPod.Status.ContainerStatuses = append(newPod.Status.ContainerStatuses, corev1.ContainerStatus{
 			Name:                 cs.Name,
 			Image:                cs.Image,

receiver/k8sclusterreceiver/internal/pod/pods_test.go

@@ -354,7 +354,8 @@ func podWithOwnerReference(kind string) *corev1.Pod {
 }
 
 func TestTransform(t *testing.T) {
-	containerState := corev1.ContainerState{Running: &corev1.ContainerStateRunning{StartedAt: v1.Now()}}
+	waitingContainerState := corev1.ContainerState{Waiting: &corev1.ContainerStateWaiting{Reason: "ImagePullBackOff"}}
+	runningContainerState := corev1.ContainerState{Running: &corev1.ContainerStateRunning{StartedAt: v1.Now()}}
 	originalPod := &corev1.Pod{
 		ObjectMeta: v1.ObjectMeta{
 			Name:      "my-pod",
@@ -384,6 +385,34 @@ func TestTransform(t *testing.T) {
 				FSGroup:    func() *int64 { gid := int64(3000); return &gid }(),
 			},
 			Containers: []corev1.Container{
+				{
+					Name:            "my-failing-container",
+					Image:           "redis:latest",
+					ImagePullPolicy: corev1.PullAlways,
+					Ports: []corev1.ContainerPort{
+						{
+							Name:          "http",
+							ContainerPort: 6379,
+							Protocol:      corev1.ProtocolTCP,
+						},
+					},
+					Env: []corev1.EnvVar{
+						{
+							Name:  "MY_ENV",
+							Value: "my-value",
+						},
+					},
+					Resources: corev1.ResourceRequirements{
+						Requests: corev1.ResourceList{
+							corev1.ResourceCPU:    resource.MustParse("500m"),
+							corev1.ResourceMemory: resource.MustParse("1Gi"),
+						},
+						Limits: corev1.ResourceList{
+							corev1.ResourceCPU:    resource.MustParse("1"),
+							corev1.ResourceMemory: resource.MustParse("2Gi"),
+						},
+					},
+				},
 				{
 					Name:            "my-container",
 					Image:           "nginx:latest",
@@ -427,17 +456,19 @@ func TestTransform(t *testing.T) {
 			StartTime: &v1.Time{Time: v1.Now().Add(-5 * time.Minute)},
 			ContainerStatuses: []corev1.ContainerStatus{
 				{
-					Name:         "invalid-container",
+					Name:         "my-failing-container",
 					Image:        "redis:latest",
 					RestartCount: 1,
+					Ready:        false,
+					State:        waitingContainerState,
 				},
 				{
 					Name:         "my-container",
 					Image:        "nginx:latest",
 					ContainerID:  "abc12345",
 					RestartCount: 2,
 					Ready:        true,
-					State:        containerState,
+					State:        runningContainerState,
 				},
 			},
 		},
@@ -454,6 +485,19 @@ func TestTransform(t *testing.T) {
 		Spec: corev1.PodSpec{
 			NodeName: "node-1",
 			Containers: []corev1.Container{
+				{
+					Name: "my-failing-container",
+					Resources: corev1.ResourceRequirements{
+						Requests: corev1.ResourceList{
+							corev1.ResourceCPU:    resource.MustParse("500m"),
+							corev1.ResourceMemory: resource.MustParse("1Gi"),
+						},
+						Limits: corev1.ResourceList{
+							corev1.ResourceCPU:    resource.MustParse("1"),
+							corev1.ResourceMemory: resource.MustParse("2Gi"),
+						},
+					},
+				},
 				{
 					Name: "my-container",
 					Resources: corev1.ResourceRequirements{
@@ -473,13 +517,21 @@ func TestTransform(t *testing.T) {
 			Phase:  corev1.PodRunning,
 			Reason: "Evicted",
 			ContainerStatuses: []corev1.ContainerStatus{
+				{
+					Name:         "my-failing-container",
+					Image:        "redis:latest",
+					ContainerID:  "",
+					RestartCount: 1,
+					Ready:        false,
+					State:        waitingContainerState,
+				},
 				{
 					Name:         "my-container",
 					Image:        "nginx:latest",
 					ContainerID:  "abc12345",
 					RestartCount: 2,
 					Ready:        true,
-					State:        containerState,
+					State:        runningContainerState,
 				},
 			},
 		},