feat(controller): Add default container annotation to workflow pod. F…

…Ixes: #5643 (#7127)

Signed-off-by: Denis Melnik <denis@codefresh.io>

workflow/common/common.go

@@ -15,6 +15,9 @@ const (
 	// DockerSockVolumeName is the volume name for the /var/run/docker.sock host path volume
 	DockerSockVolumeName = "docker-sock"
 
+	// AnnotationKeyDefaultContainer is the annotation that specify container that will be used by default in case of kubectl commands for example
+	AnnotationKeyDefaultContainer = "kubectl.kubernetes.io/default-container"
+
 	// AnnotationKeyNodeID is the ID of the node.
 	// Historically, the pod name was the same as the node ID.
 	// Therefore, if it does not exist, then the node ID is the pod name.

workflow/controller/workflowpod.go

@@ -259,6 +259,17 @@ func (woc *wfOperationCtx) createWorkflowPod(ctx context.Context, nodeName strin
 	// container's PID and root filesystem.
 	pod.Spec.Containers = append(pod.Spec.Containers, mainCtrs...)
 
+	// Configuring default container to be used with commands like "kubectl exec/logs".
+	// Select "main" container if it's available. In other case use the last container (can happent when pod created from ContainerSet).
+	defaultContainer := pod.Spec.Containers[len(pod.Spec.Containers)-1].Name
+	for _, c := range pod.Spec.Containers {
+		if c.Name == common.MainContainerName {
+			defaultContainer = common.MainContainerName
+			break
+		}
+	}
+	pod.ObjectMeta.Annotations[common.AnnotationKeyDefaultContainer] = defaultContainer
+
 	// Add init container only if it needs input artifacts. This is also true for
 	// script templates (which needs to populate the script)
 	if len(tmpl.Inputs.Artifacts) > 0 || tmpl.GetType() == wfv1.TemplateTypeScript || woc.getContainerRuntimeExecutor() == common.ContainerRuntimeExecutorEmissary {

workflow/controller/workflowpod_test.go

@@ -1699,6 +1699,44 @@ func TestPodMetadata(t *testing.T) {
 	assert.Equal(t, "world", pod.ObjectMeta.Labels["template-level-pod-label"])
 }
 
+var wfWithContainerSet = `
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  name: hello-world-with-container-set
+spec:
+  entrypoint: whalesay
+  templates:
+  - name: whalesay
+    containerSet:
+      containers:
+        - name: a
+          image: docker/whalesay:latest
+          command: [cowsay]
+          args: ["hello world"]
+        - name: b
+          image: docker/whalesay:latest
+          command: [cowsay]
+          args: ["hello world"]
+`
+
+func TestPodDefaultContainer(t *testing.T) {
+	ctx := context.Background()
+	wf := wfv1.MustUnmarshalWorkflow(wfWithContainerSet)
+	// change first container name to main
+	wf.Spec.Templates[0].ContainerSet.Containers[0].Name = common.MainContainerName
+	woc := newWoc(*wf)
+	template := woc.execWf.Spec.Templates[0]
+	pod, _ := woc.createWorkflowPod(ctx, wf.Name, template.ContainerSet.GetContainers(), &wf.Spec.Templates[0], &createWorkflowPodOpts{})
+	assert.Equal(t, common.MainContainerName, pod.ObjectMeta.Annotations[common.AnnotationKeyDefaultContainer])
+
+	wf = wfv1.MustUnmarshalWorkflow(wfWithContainerSet)
+	woc = newWoc(*wf)
+	template = woc.execWf.Spec.Templates[0]
+	pod, _ = woc.createWorkflowPod(ctx, wf.Name, template.ContainerSet.GetContainers(), &template, &createWorkflowPodOpts{})
+	assert.Equal(t, "b", pod.ObjectMeta.Annotations[common.AnnotationKeyDefaultContainer])
+}
+
 func TestGetDeadline(t *testing.T) {
 	wf := wfv1.MustUnmarshalWorkflow(helloWorldWf)
 	ctx := context.Background()