Check labels in e3e PipelineRun tests and document label propagation

The e2e tests in test/pipelinerun.go now assert that custom labels set
on the PipelineRun are propagated through to the TaskRun and Pod, and
that the static labels that are added to all TaskRuns and Pods are
propagated correctly as well.

In addition, documentation has been added to explain that labels are
propagated and to mention the specific labels that are added
automatically to generated TaskRuns and Pods.

Follow-up to tektoncd#488.

docs/pipelineruns.md

@@ -97,6 +97,26 @@ of the `TaskRun` resource object.
 For examples and more information about specifying service accounts, see the
 [`ServiceAccount`](./auth.md) reference topic.
 
+## Labels
+
+Any labels specified in the metadata field of a `PipelineRun` will be
+propagated to the `TaskRuns` created automatically for each `Task` in the
+`Pipeline` and then to the `Pods` created for those `TaskRuns`. In addition,
+the following labels will be added automatically:
+
+* `pipeline.knative.dev/pipeline` will contain the name of the `Pipeline`
+* `pipeline.knative.dev/pipelineRun` will contain the name of the `PipelineRun`
+
+These labels make it easier to find the resources that are associated with a
+given pipeline.
+
+For example, to find all `Pods` created by a `Pipeline` named test-pipeline,
+you could use the following command:
+
+```shell
+kubectl get pods --all-namespaces -l pipeline.knative.dev/pipeline=test-pipeline
+```
+
 ## Cancelling a PipelineRun
 
 In order to cancel a running pipeline (`PipelineRun`), you need to update its

docs/taskruns.md

@@ -152,6 +152,30 @@ of the `TaskRun` resource object.
 For examples and more information about specifying service accounts, see the
 [`ServiceAccount`](./auth.md) reference topic.
 
+## Labels
+
+Any labels specified in the metadata field of a `TaskRun` will be
+propagated to the `Pod` created to execute the `Task`. In addition,
+the following label will be added automatically:
+
+* `pipeline.knative.dev/taskRun` will contain the name of the `TaskRun`
+
+If the `TaskRun` was created automatically by a `PipelineRun`, then the
+following two labels will also be added to the `TaskRun` and `Pod`:
+
+* `pipeline.knative.dev/pipeline` will contain the name of the `Pipeline`
+* `pipeline.knative.dev/pipelineRun` will contain the name of the `PipelineRun`
+
+These labels make it easier to find the resources that are associated with a
+given `TaskRun`.
+
+For example, to find all `Pods` created by a `TaskRun` named test-taskrun,
+you could use the following command:
+
+```shell
+kubectl get pods --all-namespaces -l pipeline.knative.dev/taskRun=test-taskrun
+```
+
 ## Cancelling a TaskRun
 
 In order to cancel a running task (`TaskRun`), you need to update its spec to

test/pipelinerun_test.go

@@ -138,7 +138,8 @@ func TestPipelineRun(t *testing.T) {
 			td.testSetup(t, c, namespace, i)
 
 			prName := fmt.Sprintf("%s%d", pipelineRunName, i)
-			if _, err := c.PipelineRunClient.Create(td.pipelineRunFunc(i, namespace)); err != nil {
+			pr, err := c.PipelineRunClient.Create(td.pipelineRunFunc(i, namespace))
+			if err != nil {
 				t.Fatalf("Failed to create PipelineRun `%s`: %s", prName, err)
 			}
 
@@ -160,14 +161,36 @@ func TestPipelineRun(t *testing.T) {
 				if !r.Status.GetCondition(duckv1alpha1.ConditionSucceeded).IsTrue() {
 					t.Fatalf("Expected TaskRun %s to have succeeded but Status is %v", taskRunName, r.Status)
 				}
-				for name, key := range map[string]string{
-					pipelineRunName: pipeline.PipelineRunLabelKey,
-					pipelineName:    pipeline.PipelineLabelKey,
-				} {
-					expectedName := getName(name, i)
-					lbl := pipeline.GroupName + key
-					if val := r.Labels[lbl]; val != expectedName {
-						t.Errorf("Expected label %s=%s but got %s", lbl, expectedName, val)
+
+				// Check label propagation to Tasks
+				labels := make(map[string]string, len(pr.ObjectMeta.Labels)+3)
+				for key, val := range pr.ObjectMeta.Labels {
+					labels[key] = val
+				}
+				labels[pipeline.GroupName+pipeline.PipelineLabelKey] = getName(pipelineName, i)
+				labels[pipeline.GroupName+pipeline.PipelineRunLabelKey] = getName(pipelineRunName, i)
+				for key, pipelineRunVal := range labels {
+					if taskRunVal := r.ObjectMeta.Labels[key]; taskRunVal != pipelineRunVal {
+						t.Errorf("Expected label %s=%s but got %s", key, pipelineRunVal, taskRunVal)
+					}
+				}
+
+				// Check label propagation to Pods
+				taskRunLabelKey := pipeline.GroupName + pipeline.TaskRunLabelKey
+				labels[taskRunLabelKey] = taskRunName
+				pods, err := c.KubeClient.Kube.CoreV1().Pods(namespace).List(metav1.ListOptions{
+					LabelSelector: taskRunLabelKey + " = " + taskRunName,
+				})
+				if err != nil {
+					t.Fatalf("Couldn't get expected Pod for %s: %s", taskRunName, err)
+				}
+				if numPods := len(pods.Items); numPods != 1 {
+					t.Fatalf("Expected 1 Pod for %s, but got %d Pods", taskRunName, numPods)
+				}
+				pod := pods.Items[0]
+				for key, taskRunVal := range labels {
+					if podVal := pod.ObjectMeta.Labels[key]; podVal != taskRunVal {
+						t.Errorf("Expected label %s=%s but got %s", key, taskRunVal, podVal)
 					}
 				}
 			}
@@ -322,10 +345,12 @@ func getPipelineRunSecret(suffix int, namespace string) *corev1.Secret {
 }
 
 func getHelloWorldPipelineRun(suffix int, namespace string) *v1alpha1.PipelineRun {
-	return tb.PipelineRun(getName(pipelineRunName, suffix), namespace, tb.PipelineRunSpec(
-		getName(pipelineName, suffix),
-		tb.PipelineRunServiceAccount(fmt.Sprintf("%s%d", saName, suffix)),
-	))
+	return tb.PipelineRun(getName(pipelineRunName, suffix), namespace,
+		tb.PipelineRunLabel("hello-world-key", "hello-world-value"),
+		tb.PipelineRunSpec(getName(pipelineName, suffix),
+			tb.PipelineRunServiceAccount(fmt.Sprintf("%s%d", saName, suffix)),
+		),
+	)
 }
 
 func getName(namespace string, suffix int) string {