Don't rely on .status.podName to find Pod associated with a TaskRun

This adds Reconciler.getPod, which looks up the Pod for a TaskRun by
performing a label selector query on Pods, looking for the label we
apply to Pods generated by TaskRuns.

If zero Pods are returned, it's the same as .status.podName being "". If
multiple Pods are returned, that's an error.

Also, clean up metrics_test.go a bit while I'm in that area

pkg/reconciler/taskrun/cancel.go

@@ -26,28 +26,19 @@ import (
 	"knative.dev/pkg/apis"
 )
 
-type logger interface {
-	Warn(args ...interface{})
-	Warnf(template string, args ...interface{})
-}
-
 // cancelTaskRun marks the TaskRun as cancelled and delete pods linked to it.
-func cancelTaskRun(tr *v1alpha1.TaskRun, clientSet kubernetes.Interface, logger logger) error {
-	logger.Warn("task run %q has been cancelled", tr.Name)
+func cancelTaskRun(tr *v1alpha1.TaskRun, clientset kubernetes.Interface) error {
 	tr.Status.SetCondition(&apis.Condition{
 		Type:    apis.ConditionSucceeded,
 		Status:  corev1.ConditionFalse,
 		Reason:  "TaskRunCancelled",
 		Message: fmt.Sprintf("TaskRun %q was cancelled", tr.Name),
 	})
 
-	if tr.Status.PodName == "" {
-		logger.Warnf("task run %q has no pod running yet", tr.Name)
-		return nil
-	}
-
-	if err := clientSet.CoreV1().Pods(tr.Namespace).Delete(tr.Status.PodName, &metav1.DeleteOptions{}); err != nil {
+	pod, err := getPod(tr, clientset)
+	if err != nil {
 		return err
 	}
-	return nil
+
+	return clientset.CoreV1().Pods(tr.Namespace).Delete(pod.Name, &metav1.DeleteOptions{})
 }

pkg/reconciler/taskrun/cancel_test.go

@@ -22,78 +22,77 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/tektoncd/pipeline/pkg/apis/pipeline/v1alpha1"
-	ttesting "github.com/tektoncd/pipeline/pkg/reconciler/testing"
 	"github.com/tektoncd/pipeline/test"
-	tb "github.com/tektoncd/pipeline/test/builder"
-	"go.uber.org/zap"
-	"go.uber.org/zap/zaptest/observer"
 	corev1 "k8s.io/api/core/v1"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"knative.dev/pkg/apis"
 )
 
 func TestCancelTaskRun(t *testing.T) {
-	testCases := []struct {
-		name           string
-		taskRun        *v1alpha1.TaskRun
-		pod            *corev1.Pod
-		expectedStatus apis.Condition
+	namespace := "the-namespace"
+	taskRunName := "the-taskrun"
+	wantStatus := &apis.Condition{
+		Type:    apis.ConditionSucceeded,
+		Status:  corev1.ConditionFalse,
+		Reason:  "TaskRunCancelled",
+		Message: `TaskRun "the-taskrun" was cancelled`,
+	}
+	for _, c := range []struct {
+		desc    string
+		taskRun *v1alpha1.TaskRun
+		pod     *corev1.Pod
 	}{{
-		name: "no-pod-scheduled",
-		taskRun: tb.TaskRun("test-taskrun-run-cancelled", "foo", tb.TaskRunSpec(
-			tb.TaskRunTaskRef(simpleTask.Name),
-			tb.TaskRunCancelled,
-		), tb.TaskRunStatus(tb.StatusCondition(apis.Condition{
-			Type:   apis.ConditionSucceeded,
-			Status: corev1.ConditionUnknown,
-		}))),
-		expectedStatus: apis.Condition{
-			Type:    apis.ConditionSucceeded,
-			Status:  corev1.ConditionFalse,
-			Reason:  "TaskRunCancelled",
-			Message: `TaskRun "test-taskrun-run-cancelled" was cancelled`,
+		desc: "no pod scheduled",
+		taskRun: &v1alpha1.TaskRun{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      taskRunName,
+				Namespace: namespace,
+			},
+			Spec: v1alpha1.TaskRunSpec{
+				Status: v1alpha1.TaskRunSpecStatusCancelled,
+			},
 		},
 	}, {
-		name: "pod-scheduled",
-		taskRun: tb.TaskRun("test-taskrun-run-cancelled", "foo", tb.TaskRunSpec(
-			tb.TaskRunTaskRef(simpleTask.Name),
-			tb.TaskRunCancelled,
-		), tb.TaskRunStatus(tb.StatusCondition(apis.Condition{
-			Type:   apis.ConditionSucceeded,
-			Status: corev1.ConditionUnknown,
-		}), tb.PodName("foo-is-bar"))),
+		desc: "pod scheduled",
+		taskRun: &v1alpha1.TaskRun{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      taskRunName,
+				Namespace: namespace,
+			},
+			Spec: v1alpha1.TaskRunSpec{
+				Status: v1alpha1.TaskRunSpecStatusCancelled,
+			},
+		},
 		pod: &corev1.Pod{ObjectMeta: metav1.ObjectMeta{
-			Namespace: "foo",
-			Name:      "foo-is-bar",
+			Namespace: namespace,
+			Name:      "the-pod",
+			Labels: map[string]string{
+				"tekton.dev/taskRun": taskRunName,
+			},
 		}},
-		expectedStatus: apis.Condition{
-			Type:    apis.ConditionSucceeded,
-			Status:  corev1.ConditionFalse,
-			Reason:  "TaskRunCancelled",
-			Message: `TaskRun "test-taskrun-run-cancelled" was cancelled`,
-		},
-	}}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
+	}} {
+		t.Run(c.desc, func(t *testing.T) {
 			d := test.Data{
-				TaskRuns: []*v1alpha1.TaskRun{tc.taskRun},
+				TaskRuns: []*v1alpha1.TaskRun{c.taskRun},
 			}
-			if tc.pod != nil {
-				d.Pods = []*corev1.Pod{tc.pod}
+			if c.pod != nil {
+				d.Pods = []*corev1.Pod{c.pod}
 			}
 
-			ctx, _ := ttesting.SetupFakeContext(t)
-			ctx, cancel := context.WithCancel(ctx)
+			testAssets, cancel := getTaskRunController(t, d)
 			defer cancel()
-			c, _ := test.SeedTestData(t, ctx, d)
-			observer, _ := observer.New(zap.InfoLevel)
-			err := cancelTaskRun(tc.taskRun, c.Kube, zap.New(observer).Sugar())
-			if err != nil {
+			if err := testAssets.Controller.Reconciler.Reconcile(context.Background(), getRunName(c.taskRun)); err != nil {
 				t.Fatal(err)
 			}
-			if d := cmp.Diff(tc.taskRun.Status.GetCondition(apis.ConditionSucceeded), &tc.expectedStatus, ignoreLastTransitionTime); d != "" {
-				t.Fatalf("-want, +got: %v", d)
+			if d := cmp.Diff(wantStatus, c.taskRun.Status.GetCondition(apis.ConditionSucceeded), ignoreLastTransitionTime); d != "" {
+				t.Errorf("Diff(-want, +got): %s", d)
+			}
+
+			if c.pod != nil {
+				if _, err := testAssets.Controller.Reconciler.(*Reconciler).KubeClientSet.CoreV1().Pods(c.taskRun.Namespace).Get(c.pod.Name, metav1.GetOptions{}); !kerrors.IsNotFound(err) {
+					t.Errorf("Pod was not deleted; wanted not-found error, got %v", err)
+				}
 			}
 		})
 	}

pkg/reconciler/taskrun/metrics.go

@@ -120,7 +120,7 @@ func NewRecorder() (*Recorder, error) {
 	}
 	r.pod = pod
 
-	err = view.Register(
+	if err := view.Register(
 		&view.View{
 			Description: trDuration.Description(),
 			Measure:     trDuration,
@@ -150,9 +150,7 @@ func NewRecorder() (*Recorder, error) {
 			Aggregation: view.LastValue(),
 			TagKeys:     []tag.Key{r.task, r.taskRun, r.namespace, r.pod},
 		},
-	)
-
-	if err != nil {
+	); err != nil {
 		r.initialized = false
 		return r, err
 	}
@@ -257,9 +255,15 @@ func (r *Recorder) RecordPodLatency(pod *corev1.Pod, tr *v1alpha1.TaskRun) error
 		return errors.New("ignoring the metrics recording for pod , failed to initialize the metrics recorder")
 	}
 
-	scheduledTime := getScheduledTime(pod)
+	var scheduledTime metav1.Time
+	for _, c := range pod.Status.Conditions {
+		if c.Type == corev1.PodScheduled {
+			scheduledTime = c.LastTransitionTime
+			break
+		}
+	}
 	if scheduledTime.IsZero() {
-		return errors.New("pod has never got scheduled")
+		return errors.New("pod was never scheduled")
 	}
 
 	latency := scheduledTime.Sub(pod.CreationTimestamp.Time)
@@ -283,13 +287,3 @@ func (r *Recorder) RecordPodLatency(pod *corev1.Pod, tr *v1alpha1.TaskRun) error
 
 	return nil
 }
-
-func getScheduledTime(pod *corev1.Pod) metav1.Time {
-	for _, c := range pod.Status.Conditions {
-		if c.Type == corev1.PodScheduled {
-			return c.LastTransitionTime
-		}
-	}
-
-	return metav1.Time{}
-}