Mark ephemeral pods created as part of kanister functions with JobID label

pkg/function/kube_task.go

@@ -16,6 +16,8 @@ package function
 
 import (
 	"context"
+	"path"
+	"strings"
 	"time"
 
 	"github.com/pkg/errors"
@@ -33,7 +35,9 @@ import (
 )
 
 const (
-	jobPrefix = "kanister-job-"
+	jobPrefix   = "kanister-job-"
+	jobIDSuffix = "JobID"
+
 	// KubeTaskFuncName gives the function name
 	KubeTaskFuncName       = "KubeTask"
 	KubeTaskNamespaceArg   = "namespace"
@@ -64,6 +68,9 @@ func kubeTask(ctx context.Context, cli kubernetes.Interface, namespace, image st
 		Command:      command,
 		PodOverride:  podOverride,
 	}
+	// Mark labels to pods with prefix `kanister.io`. Add the jobID as reference to the origin for the pod.
+	validateFunc := validateLabelKeyIsPresentFunc(consts.LabelPrefix)
+	kube.AddLabelsToPodOptionsFromContext(ctx, options, path.Join(consts.LabelPrefix, jobIDSuffix), validateFunc)
 
 	pr := kube.NewPodRunner(cli, options)
 	podFunc := kubeTaskPodFunc()
@@ -93,6 +100,23 @@ func kubeTaskPodFunc() func(ctx context.Context, pc kube.PodController) (map[str
 	}
 }
 
+// validateLabelKeyIsPresentFunc: This is a helper validation function used by kubetask to validate the presence of
+// label key. Result of this is used to add target label selector to the pod
+func validateLabelKeyIsPresentFunc(keyPrefix string) func(ctx context.Context) (bool, string) {
+	return func(ctx context.Context) (bool, string) {
+		fields := field.FromContext(ctx)
+		if fields == nil {
+			return false, ""
+		}
+		for _, f := range fields.Fields() {
+			if strings.HasPrefix(f.Key(), keyPrefix) {
+				return true, f.Value().(string)
+			}
+		}
+		return false, ""
+	}
+}
+
 func (ktf *kubeTaskFunc) Exec(ctx context.Context, tp param.TemplateParams, args map[string]interface{}) (map[string]interface{}, error) {
 	// Set progress percent
 	ktf.progressPercent = progress.StartedPercent

pkg/kube/pod_runner_test.go

@@ -18,11 +18,16 @@ import (
 	"context"
 	"os"
 
+	"github.com/pkg/errors"
 	. "gopkg.in/check.v1"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/kubernetes/fake"
 	"k8s.io/client-go/testing"
+
+	"github.com/kanisterio/kanister/pkg/consts"
+	"github.com/kanisterio/kanister/pkg/field"
+	"path"
 )
 
 type PodRunnerTestSuite struct{}
@@ -109,9 +114,99 @@ func (s *PodRunnerTestSuite) TestPodRunnerForSuccessCase(c *C) {
 	cancel()
 }
 
+// TestPodRunnerWithJobIDDebugLabelForSuccessCase: This test adds a debug entry (kanister.io/JobID) into the context and verifies the
+// pod got created with corresponding label using the entry or not.
+func (s *PodRunnerTestSuite) TestPodRunnerWithJobIDDebugLabelForSuccessCase(c *C) {
+	randomUUID := "xyz123"
+	for _, tc := range []struct {
+		name              string
+		validateFn        func(_ context.Context) (bool, string)
+		afterPodRunTestFn func(labelKey, labelValue string, ch chan struct{}) func(ctx context.Context, pc PodController) (map[string]interface{}, error)
+	}{
+		{
+			name: "test key not present in context",
+			validateFn: func(_ context.Context) (bool, string) {
+				return false, ""
+			},
+			afterPodRunTestFn: afterPodRunTestKeyAbsentFunc,
+		},
+		{
+			name: "test key is present in context",
+			validateFn: func(_ context.Context) (bool, string) {
+				return true, randomUUID
+			},
+			afterPodRunTestFn: afterPodRunTestKeyPresentFunc,
+		},
+	} {
+		ctx, cancel := context.WithCancel(context.Background())
+		ctx = field.Context(ctx, consts.LabelPrefix+"JobID", randomUUID)
+		ctx = field.Context(ctx, "some-test-key", "some-test-value")
+
+		cli := fake.NewSimpleClientset()
+		cli.PrependReactor("create", "pods", func(action testing.Action) (handled bool, ret runtime.Object, err error) {
+			return false, nil, nil
+		})
+		cli.PrependReactor("get", "pods", func(action testing.Action) (handled bool, ret runtime.Object, err error) {
+			p := &corev1.Pod{
+				Status: corev1.PodStatus{
+					Phase: corev1.PodRunning,
+				},
+			}
+			return true, p, nil
+		})
+		po := &PodOptions{
+			Namespace: podRunnerNS,
+			Name:      podName,
+			Command:   []string{"sh", "-c", "tail -f /dev/null"},
+		}
+		deleted := make(chan struct{})
+		cli.PrependReactor("delete", "pods", func(action testing.Action) (handled bool, ret runtime.Object, err error) {
+			c.Log("Pod deleted due to Context Cancelled")
+			close(deleted)
+			return true, nil, nil
+		})
+		var targetKey = path.Join(consts.LabelPrefix, "JobID")
+		AddLabelsToPodOptionsFromContext(ctx, po, targetKey, tc.validateFn)
+		pr := NewPodRunner(cli, po)
+		errorCh := make(chan error)
+		go func() {
+			_, err := pr.Run(ctx, tc.afterPodRunTestFn(targetKey, randomUUID, deleted))
+			errorCh <- err
+		}()
+		deleted <- struct{}{}
+		c.Assert(<-errorCh, IsNil)
+		cancel()
+	}
+}
+
 func makePodRunnerTestFunc(ch chan struct{}) func(ctx context.Context, pc PodController) (map[string]interface{}, error) {
 	return func(ctx context.Context, pc PodController) (map[string]interface{}, error) {
 		<-ch
 		return nil, nil
 	}
 }
+
+func afterPodRunTestKeyPresentFunc(labelKey, labelValue string, ch chan struct{}) func(ctx context.Context, pc PodController) (map[string]interface{}, error) {
+	return func(ctx context.Context, pc PodController) (map[string]interface{}, error) {
+		<-ch
+		value, ok := pc.Pod().Labels[labelKey]
+		if !ok {
+			return nil, errors.New("Key not present")
+		}
+		if value != labelValue {
+			return nil, errors.New("Value mismatch")
+		}
+		return nil, nil
+	}
+}
+
+func afterPodRunTestKeyAbsentFunc(labelKey, labelValue string, ch chan struct{}) func(ctx context.Context, pc PodController) (map[string]interface{}, error) {
+	return func(ctx context.Context, pc PodController) (map[string]interface{}, error) {
+		<-ch
+		_, present := pc.Pod().Labels[labelKey]
+		if present {
+			return nil, errors.New("Key should not be present")
+		}
+		return nil, nil
+	}
+}

pkg/kube/utils.go

@@ -171,3 +171,21 @@ func PVCContainsReadOnlyAccessMode(pvc *corev1.PersistentVolumeClaim) bool {
 
 	return false
 }
+
+// AddLabelsToPodOptionsFromContext adds additional label selector to `PodOptions`,
+// provided the validationFunc passes successfully.
+func AddLabelsToPodOptionsFromContext(
+	ctx context.Context,
+	options *PodOptions,
+	targetKey string,
+	validateFn func(context.Context) (bool, string),
+) {
+	ok, value := validateFn(ctx)
+	if !ok {
+		return
+	}
+	if options.Labels == nil {
+		options.Labels = make(map[string]string)
+	}
+	options.Labels[targetKey] = value
+}