Recreate pod on TaskRun's pod deletion

pkg/reconciler/v1alpha1/taskrun/resources/pod.go

@@ -29,6 +29,7 @@ import (
 
 	"go.uber.org/zap"
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
@@ -160,6 +161,23 @@ func makeCredentialInitializer(serviceAccountName, namespace string, kubeclient
 	}, volumes, nil
 }
 
+// GetPod returns the Pod for the given pod name
+type GetPod func(string, metav1.GetOptions) (*corev1.Pod, error)
+
+// TryGetPod fetches the TaskRun's pod, returning nil if it has not been created or it does not exist.
+func TryGetPod(taskRunStatus v1alpha1.TaskRunStatus, gp GetPod) (*corev1.Pod, error) {
+	if taskRunStatus.PodName == "" {
+		return nil, nil
+	}
+
+	pod, err := gp(taskRunStatus.PodName, metav1.GetOptions{})
+	if err == nil || errors.IsNotFound(err) {
+		return pod, nil
+	}
+
+	return nil, err
+}
+
 // MakePod converts TaskRun and TaskSpec objects to a Pod which implements the taskrun specified
 // by the supplied CRD.
 func MakePod(taskRun *v1alpha1.TaskRun, taskSpec v1alpha1.TaskSpec, kubeclient kubernetes.Interface, cache *entrypoint.Cache, logger *zap.SugaredLogger) (*corev1.Pod, error) {

pkg/reconciler/v1alpha1/taskrun/resources/pod_test.go

@@ -18,13 +18,16 @@ package resources
 
 import (
 	"crypto/rand"
+	"fmt"
 	"strings"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 	fakek8s "k8s.io/client-go/kubernetes/fake"
 
 	"github.com/tektoncd/pipeline/pkg/apis/pipeline/v1alpha1"
@@ -48,6 +51,68 @@ var (
 	}
 )
 
+func TestTryGetPod(t *testing.T) {
+	err := fmt.Errorf("something went wrong")
+	for _, c := range []struct {
+		desc    string
+		trs     v1alpha1.TaskRunStatus
+		gp      GetPod
+		wantNil bool
+		wantErr error
+	}{{
+		desc: "no-pod",
+		trs:  v1alpha1.TaskRunStatus{},
+		gp: func(string, metav1.GetOptions) (*corev1.Pod, error) {
+			t.Errorf("Did not expect pod to be fetched")
+			return nil, nil
+		},
+		wantNil: true,
+		wantErr: nil,
+	}, {
+		desc: "non-existent-pod",
+		trs: v1alpha1.TaskRunStatus{
+			PodName: "no-longer-exist",
+		},
+		gp: func(name string, opts metav1.GetOptions) (*corev1.Pod, error) {
+			return nil, errors.NewNotFound(schema.GroupResource{}, name)
+		},
+		wantNil: true,
+		wantErr: nil,
+	}, {
+		desc: "existing-pod",
+		trs: v1alpha1.TaskRunStatus{
+			PodName: "exists",
+		},
+		gp: func(name string, opts metav1.GetOptions) (*corev1.Pod, error) {
+			return &corev1.Pod{}, nil
+		},
+		wantNil: false,
+		wantErr: nil,
+	}, {
+		desc: "pod-fetch-error",
+		trs: v1alpha1.TaskRunStatus{
+			PodName: "something-went-wrong",
+		},
+		gp: func(name string, opts metav1.GetOptions) (*corev1.Pod, error) {
+			return nil, err
+		},
+		wantNil: true,
+		wantErr: err,
+	}} {
+		t.Run(c.desc, func(t *testing.T) {
+			pod, err := TryGetPod(c.trs, c.gp)
+			if err != c.wantErr {
+				t.Fatalf("TryGetPod: %v", err)
+			}
+
+			wasNil := pod == nil
+			if wasNil != c.wantNil {
+				t.Errorf("Pod got %v, want %v", wasNil, c.wantNil)
+			}
+		})
+	}
+}
+
 func TestMakePod(t *testing.T) {
 	names.TestingSeed()
 	subPath := "subpath"

pkg/reconciler/v1alpha1/taskrun/taskrun.go

@@ -275,14 +275,12 @@ func (c *Reconciler) reconcile(ctx context.Context, tr *v1alpha1.TaskRun) error
 	}
 
 	// Get the TaskRun's Pod if it should have one. Otherwise, create the Pod.
-	var pod *corev1.Pod
-	if tr.Status.PodName != "" {
-		pod, err = c.KubeClientSet.CoreV1().Pods(tr.Namespace).Get(tr.Status.PodName, metav1.GetOptions{})
-		if err != nil {
-			c.Logger.Errorf("Error getting pod %q: %v", tr.Status.PodName, err)
-			return err
-		}
-	} else {
+	pod, err := resources.TryGetPod(tr.Status, c.KubeClientSet.CoreV1().Pods(tr.Namespace).Get)
+	if err != nil {
+		c.Logger.Errorf("Error getting pod %q: %v", tr.Status.PodName, err)
+		return err
+	}
+	if pod == nil {
 		// Pod is not present, create pod.
 		pod, err = c.createPod(tr, rtr.TaskSpec, rtr.TaskName)
 		if err != nil {

pkg/reconciler/v1alpha1/taskrun/taskrun_test.go

@@ -333,11 +333,16 @@ func TestReconcile(t *testing.T) {
 		),
 	)
 
+	taskRunWithPod := tb.TaskRun("test-taskrun-with-pod", "foo",
+		tb.TaskRunSpec(tb.TaskRunTaskRef(simpleTask.Name)),
+		tb.TaskRunStatus(tb.PodName("some-pod-that-no-longer-exists")),
+	)
+
 	taskruns := []*v1alpha1.TaskRun{
 		taskRunSuccess, taskRunWithSaSuccess,
 		taskRunTemplating, taskRunInputOutput,
 		taskRunWithTaskSpec, taskRunWithClusterTask, taskRunWithResourceSpecAndTaskSpec,
-		taskRunWithLabels, taskRunWithResourceRequests, taskRunTaskEnv,
+		taskRunWithLabels, taskRunWithResourceRequests, taskRunTaskEnv, taskRunWithPod,
 	}
 
 	d := test.Data{
@@ -911,6 +916,41 @@ func TestReconcile(t *testing.T) {
 				),
 			),
 		),
+	}, {
+		name:    "taskrun-with-pod",
+		taskRun: taskRunWithPod,
+		wantPod: tb.Pod("test-taskrun-with-pod-pod-123456", "foo",
+			tb.PodAnnotation("sidecar.istio.io/inject", "false"),
+			tb.PodLabel(taskNameLabelKey, "test-task"),
+			tb.PodLabel(taskRunNameLabelKey, "test-taskrun-with-pod"),
+			tb.PodOwnerReference("TaskRun", "test-taskrun-with-pod",
+				tb.OwnerReferenceAPIVersion(currentApiVersion)),
+			tb.PodSpec(
+				tb.PodVolumes(toolsVolume, workspaceVolume, homeVolume),
+				tb.PodRestartPolicy(corev1.RestartPolicyNever),
+				getCredentialsInitContainer("9l9zj"),
+				getPlaceToolsInitContainer(),
+				tb.PodContainer("build-step-simple-step", "foo",
+					tb.Command(entrypointLocation),
+					tb.Args("-wait_file", "", "-post_file", "/builder/tools/0", "-entrypoint", "/mycmd", "--"),
+					tb.WorkingDir(workspaceDir),
+					tb.EnvVar("HOME", "/builder/home"),
+					tb.VolumeMount("tools", "/builder/tools"),
+					tb.VolumeMount("workspace", workspaceDir),
+					tb.VolumeMount("home", "/builder/home"),
+					tb.Resources(tb.Requests(
+						tb.CPU("0"),
+						tb.Memory("0"),
+						tb.EphemeralStorage("0"),
+					)),
+				),
+				tb.PodContainer("nop", "override-with-nop:latest",
+					tb.Command("/builder/tools/entrypoint"),
+					tb.Args("-wait_file", "/builder/tools/0", "-post_file", "/builder/tools/1", "-entrypoint", "/ko-app/nop", "--"),
+					tb.VolumeMount(entrypoint.MountName, entrypoint.MountPoint),
+				),
+			),
+		),
 	}} {
 		t.Run(tc.name, func(t *testing.T) {
 			names.TestingSeed()