Add option to support cascade deletion options

Add --cascade=<background|foreground|orphan> option to helm uninstall
Current behaviour is hardcoded to background

Addresses issue: https://github.com/helm/helm/issues/10586

Signed-off-by: MichaelMorris <michael.morris@est.tech>

cmd/helm/uninstall.go

@@ -51,6 +51,10 @@ func newUninstallCmd(cfg *action.Configuration, out io.Writer) *cobra.Command {
 			return compListReleases(toComplete, args, cfg)
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
+			validationErr := validateCascadeFlag(client)
+			if validationErr != nil {
+				return validationErr
+			}
 			for i := 0; i < len(args); i++ {
 
 				res, err := client.Run(args[i])
@@ -72,8 +76,16 @@ func newUninstallCmd(cfg *action.Configuration, out io.Writer) *cobra.Command {
 	f.BoolVar(&client.DisableHooks, "no-hooks", false, "prevent hooks from running during uninstallation")
 	f.BoolVar(&client.KeepHistory, "keep-history", false, "remove all associated resources and mark the release as deleted, but retain the release history")
 	f.BoolVar(&client.Wait, "wait", false, "if set, will wait until all the resources are deleted before returning. It will wait for as long as --timeout")
+	f.StringVar(&client.DeletionPropagation, "cascade", "background", "Must be \"background\", \"orphan\", or \"foreground\". Selects the deletion cascading strategy for the dependents. Defaults to background.")
 	f.DurationVar(&client.Timeout, "timeout", 300*time.Second, "time to wait for any individual Kubernetes operation (like Jobs for hooks)")
 	f.StringVar(&client.Description, "description", "", "add a custom description")
 
 	return cmd
 }
+
+func validateCascadeFlag(client *action.Uninstall) error {
+	if client.DeletionPropagation != "background" && client.DeletionPropagation != "foreground" && client.DeletionPropagation != "orphan" {
+		return fmt.Errorf("invalid cascade value (%s). Must be \"background\", \"foreground\", or \"orphan\"", client.DeletionPropagation)
+	}
+	return nil
+}

pkg/action/uninstall.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"helm.sh/helm/v3/pkg/chartutil"
 	"helm.sh/helm/v3/pkg/kube"
@@ -39,6 +40,7 @@ type Uninstall struct {
 	DryRun              bool
 	KeepHistory         bool
 	Wait                bool
+	DeletionPropagation string
 	Timeout             time.Duration
 	Description         string
 }
@@ -220,7 +222,25 @@ func (u *Uninstall) deleteRelease(rel *release.Release) (kube.ResourceList, stri
 		return nil, "", []error{errors.Wrap(err, "unable to build kubernetes objects for delete")}
 	}
 	if len(resources) > 0 {
+		if kubeClient, ok := u.cfg.KubeClient.(kube.InterfaceDeletionPropagation); ok {
+			_, errs = kubeClient.DeleteWithPropagationPolicy(resources, parseCascadingFlag(u.cfg, u.DeletionPropagation))
+			return resources, kept, errs
+		}
 		_, errs = u.cfg.KubeClient.Delete(resources)
 	}
 	return resources, kept, errs
 }
+
+func parseCascadingFlag(cfg *Configuration, cascadingFlag string) v1.DeletionPropagation {
+	switch cascadingFlag {
+	case "orphan":
+		return v1.DeletePropagationOrphan
+	case "foreground":
+		return v1.DeletePropagationForeground
+	case "background":
+		return v1.DeletePropagationBackground
+	default:
+		cfg.Log("uninstall: given cascade value: %s, defaulting to delete propagation background", cascadingFlag)
+		return v1.DeletePropagationBackground
+	}
+}

pkg/action/uninstall_test.go

@@ -95,3 +95,35 @@ func TestUninstallRelease_Wait(t *testing.T) {
 	is.Contains(err.Error(), "U timed out")
 	is.Equal(res.Release.Info.Status, release.StatusUninstalled)
 }
+
+func TestUninstallRelease_Cascade(t *testing.T) {
+	is := assert.New(t)
+
+	unAction := uninstallAction(t)
+	unAction.DisableHooks = true
+	unAction.DryRun = false
+	unAction.Wait = false
+	unAction.DeletionPropagation = "foreground"
+
+	rel := releaseStub()
+	rel.Name = "come-fail-away"
+	rel.Manifest = `{
+		"apiVersion": "v1",
+		"kind": "Secret",
+		"metadata": {
+		  "name": "secret"
+		},
+		"type": "Opaque",
+		"data": {
+		  "password": "password"
+		}
+	}`
+	unAction.cfg.Releases.Create(rel)
+	failer := unAction.cfg.KubeClient.(*kubefake.FailingKubeClient)
+	failer.DeleteWithPropagationError = fmt.Errorf("Uninstall with cascade failed")
+	failer.BuildDummy = true
+	unAction.cfg.KubeClient = failer
+	_, err := unAction.Run(rel.Name)
+	is.Error(err)
+	is.Contains(err.Error(), "failed to delete release: come-fail-away")
+}

pkg/kube/client.go

@@ -456,7 +456,7 @@ func (c *Client) Update(original, target ResourceList, force bool) (*Result, err
 			c.Log("Skipping delete of %q due to annotation [%s=%s]", info.Name, ResourcePolicyAnno, KeepPolicy)
 			continue
 		}
-		if err := deleteResource(info); err != nil {
+		if err := deleteResource(info, metav1.DeletePropagationBackground); err != nil {
 			c.Log("Failed to delete %q, err: %s", info.ObjectName(), err)
 			continue
 		}
@@ -465,17 +465,29 @@ func (c *Client) Update(original, target ResourceList, force bool) (*Result, err
 	return res, nil
 }
 
-// Delete deletes Kubernetes resources specified in the resources list. It will
-// attempt to delete all resources even if one or more fail and collect any
-// errors. All successfully deleted items will be returned in the `Deleted`
-// ResourceList that is part of the result.
+// Delete deletes Kubernetes resources specified in the resources list with
+// background cascade deletion. It will attempt to delete all resources even
+// if one or more fail and collect any errors. All successfully deleted items
+// will be returned in the `Deleted` ResourceList that is part of the result.
 func (c *Client) Delete(resources ResourceList) (*Result, []error) {
+	return delete(c, resources, metav1.DeletePropagationBackground)
+}
+
+// Delete deletes Kubernetes resources specified in the resources list with
+// given deletion propagation policy. It will attempt to delete all resources even
+// if one or more fail and collect any errors. All successfully deleted items
+// will be returned in the `Deleted` ResourceList that is part of the result.
+func (c *Client) DeleteWithPropagationPolicy(resources ResourceList, policy metav1.DeletionPropagation) (*Result, []error) {
+	return delete(c, resources, policy)
+}
+
+func delete(c *Client, resources ResourceList, propagation metav1.DeletionPropagation) (*Result, []error) {
 	var errs []error
 	res := &Result{}
 	mtx := sync.Mutex{}
 	err := perform(resources, func(info *resource.Info) error {
 		c.Log("Starting delete for %q %s", info.Name, info.Mapping.GroupVersionKind.Kind)
-		err := deleteResource(info)
+		err := deleteResource(info, propagation)
 		if err == nil || apierrors.IsNotFound(err) {
 			if err != nil {
 				c.Log("Ignoring delete failure for %q %s: %v", info.Name, info.Mapping.GroupVersionKind, err)
@@ -593,8 +605,7 @@ func createResource(info *resource.Info) error {
 	return info.Refresh(obj, true)
 }
 
-func deleteResource(info *resource.Info) error {
-	policy := metav1.DeletePropagationBackground
+func deleteResource(info *resource.Info, policy metav1.DeletionPropagation) error {
 	opts := &metav1.DeleteOptions{PropagationPolicy: &policy}
 	_, err := resource.NewHelper(info.Client, info.Mapping).WithFieldManager(getManagedFieldsManager()).DeleteWithOptions(info.Namespace, info.Name, opts)
 	return err

pkg/kube/fake/fake.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/cli-runtime/pkg/resource"
 
@@ -37,10 +38,12 @@ type FailingKubeClient struct {
 	GetError                         error
 	WaitError                        error
 	DeleteError                      error
+	DeleteWithPropagationError       error
 	WatchUntilReadyError             error
 	UpdateError                      error
 	BuildError                       error
 	BuildTableError                  error
+	BuildDummy                       bool
 	BuildUnstructuredError           error
 	WaitAndGetCompletedPodPhaseError error
 	WaitDuration                     time.Duration
@@ -116,6 +119,9 @@ func (f *FailingKubeClient) Build(r io.Reader, _ bool) (kube.ResourceList, error
 	if f.BuildError != nil {
 		return []*resource.Info{}, f.BuildError
 	}
+	if f.BuildDummy {
+		return createDummyResourceList(), nil
+	}
 	return f.PrintingKubeClient.Build(r, false)
 }
 
@@ -134,3 +140,21 @@ func (f *FailingKubeClient) WaitAndGetCompletedPodPhase(s string, d time.Duratio
 	}
 	return f.PrintingKubeClient.WaitAndGetCompletedPodPhase(s, d)
 }
+
+// DeleteWithPropagationPolicy returns the configured error if set or prints
+func (f *FailingKubeClient) DeleteWithPropagationPolicy(resources kube.ResourceList, policy metav1.DeletionPropagation) (*kube.Result, []error) {
+	if f.DeleteWithPropagationError != nil {
+		return nil, []error{f.DeleteWithPropagationError}
+	}
+	return f.PrintingKubeClient.DeleteWithPropagationPolicy(resources, policy)
+}
+
+func createDummyResourceList() kube.ResourceList {
+	var resInfo resource.Info
+	resInfo.Name = "dummyName"
+	resInfo.Namespace = "dummyNamespace"
+	var resourceList kube.ResourceList
+	resourceList.Append(&resInfo)
+	return resourceList
+
+}

pkg/kube/fake/printer.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/cli-runtime/pkg/resource"
 
@@ -115,6 +116,17 @@ func (p *PrintingKubeClient) WaitAndGetCompletedPodPhase(_ string, _ time.Durati
 	return v1.PodSucceeded, nil
 }
 
+// DeleteWithPropagationPolicy implements KubeClient delete.
+//
+// It only prints out the content to be deleted.
+func (p *PrintingKubeClient) DeleteWithPropagationPolicy(resources kube.ResourceList, policy metav1.DeletionPropagation) (*kube.Result, []error) {
+	_, err := io.Copy(p.Out, bufferize(resources))
+	if err != nil {
+		return nil, []error{err}
+	}
+	return &kube.Result{Deleted: resources}, nil
+}
+
 func bufferize(resources kube.ResourceList) io.Reader {
 	var builder strings.Builder
 	for _, info := range resources {

pkg/kube/interface.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
@@ -79,6 +80,14 @@ type InterfaceExt interface {
 	WaitForDelete(resources ResourceList, timeout time.Duration) error
 }
 
+// InterfaceDeletionPropagation is introduced to avoid breaking backwards compatibility for Interface implementers.
+//
+// TODO Helm 4: Remove InterfaceDeletionPropagation and integrate its method(s) into the Interface.
+type InterfaceDeletionPropagation interface {
+	// Delete destroys one or more resources. The deletion propagation is handled as per the given deletion propagation value.
+	DeleteWithPropagationPolicy(resources ResourceList, policy metav1.DeletionPropagation) (*Result, []error)
+}
+
 // InterfaceResources is introduced to avoid breaking backwards compatibility for Interface implementers.
 //
 // TODO Helm 4: Remove InterfaceResources and integrate its method(s) into the Interface.
@@ -103,4 +112,5 @@ type InterfaceResources interface {
 
 var _ Interface = (*Client)(nil)
 var _ InterfaceExt = (*Client)(nil)
+var _ InterfaceDeletionPropagation = (*Client)(nil)
 var _ InterfaceResources = (*Client)(nil)