Add checking of length of resourceList before creating of deleting

A chart being installed which only contains CRDs and not
any templates tries to install the resources by default.
The resourceList which is used in this case does not check
if there are resources present in it or not. This commit
adds checks to those particular places where we need to check
if the size of resourceList > 0 during installation and deletion.
Signed-off-by: Vibhav Bobade <vibhav.bobde@gmail.com>

cmd/helm/install_test.go

@@ -189,6 +189,11 @@ func TestInstall(t *testing.T) {
 			cmd:    "install aeneas testdata/testcharts/deprecated --namespace default",
 			golden: "output/deprecated-chart.txt",
 		},
+		// Install chart with only crds
+		{
+			name: "install chart with only crds",
+			cmd:  "install crd-test testdata/testcharts/chart-with-only-crds --namespace default",
+		},
 	}
 
 	runTestActionCmd(t, tests)

cmd/helm/testdata/testcharts/chart-with-only-crds/.helmignore

+# Patterns to ignore when building packages.
+# This supports shell glob matching, relative path matching, and
+# negation (prefixed with !). Only one pattern per line.
+.DS_Store
+# Common VCS dirs
+.git/
+.gitignore
+.bzr/
+.bzrignore
+.hg/
+.hgignore
+.svn/
+# Common backup files
+*.swp
+*.bak
+*.tmp
+*.orig
+*~
+# Various IDEs
+.project
+.idea/
+*.tmproj
+.vscode/

cmd/helm/testdata/testcharts/chart-with-only-crds/Chart.yaml

+apiVersion: v2
+name: crd-test
+description: A Helm chart for Kubernetes
+
+# A chart can be either an 'application' or a 'library' chart.
+#
+# Application charts are a collection of templates that can be packaged into versioned archives
+# to be deployed.
+#
+# Library charts provide useful utilities or functions for the chart developer. They're included as
+# a dependency of application charts to inject those utilities and functions into the rendering
+# pipeline. Library charts do not define any templates and therefore cannot be deployed.
+type: application
+
+# This is the chart version. This version number should be incremented each time you make changes
+# to the chart and its templates, including the app version.
+version: 0.1.0
+
+# This is the version number of the application being deployed. This version number should be
+# incremented each time you make changes to the application.
+appVersion: 1.16.0

cmd/helm/testdata/testcharts/chart-with-only-crds/crds/test-crd.yaml

+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
+metadata:
+  name: tests.test.io
+spec:
+  group: test.io
+  names:
+    kind: Test
+    listKind: TestList
+    plural: tests
+    singular: test
+  scope: Namespaced
+  versions:
+    - name : v1alpha2
+      served: true
+      storage: true
+    - name : v1alpha1
+      served: true
+      storage: false

pkg/action/install.go

@@ -145,20 +145,24 @@ func (i *Install) installCRDs(crds []chart.CRD) error {
 		}
 		totalItems = append(totalItems, res...)
 	}
-	// Invalidate the local cache, since it will not have the new CRDs
-	// present.
-	discoveryClient, err := i.cfg.RESTClientGetter.ToDiscoveryClient()
-	if err != nil {
-		return err
-	}
-	i.cfg.Log("Clearing discovery cache")
-	discoveryClient.Invalidate()
-	// Give time for the CRD to be recognized.
-	if err := i.cfg.KubeClient.Wait(totalItems, 60*time.Second); err != nil {
-		return err
+	if len(totalItems) > 0 {
+		// Invalidate the local cache, since it will not have the new CRDs
+		// present.
+		discoveryClient, err := i.cfg.RESTClientGetter.ToDiscoveryClient()
+		if err != nil {
+			return err
+		}
+		i.cfg.Log("Clearing discovery cache")
+		discoveryClient.Invalidate()
+		// Give time for the CRD to be recognized.
+
+		if err := i.cfg.KubeClient.Wait(totalItems, 60*time.Second); err != nil {
+			return err
+		}
+
+		// Make sure to force a rebuild of the cache.
+		discoveryClient.ServerGroups()
 	}
-	// Make sure to force a rebuild of the cache.
-	discoveryClient.ServerGroups()
 	return nil
 }
 
@@ -265,7 +269,7 @@ func (i *Install) Run(chrt *chart.Chart, vals map[string]interface{}) (*release.
 	// we'll end up in a state where we will delete those resources upon
 	// deleting the release because the manifest will be pointing at that
 	// resource
-	if !i.ClientOnly && !isUpgrade {
+	if !i.ClientOnly && !isUpgrade && len(resources) > 0 {
 		toBeAdopted, err = existingResourceConflict(resources, rel.Name, rel.Namespace)
 		if err != nil {
 			return nil, errors.Wrap(err, "rendered manifests contain a resource that already exists. Unable to continue with install")
@@ -330,11 +334,11 @@ func (i *Install) Run(chrt *chart.Chart, vals map[string]interface{}) (*release.
 	// At this point, we can do the install. Note that before we were detecting whether to
 	// do an update, but it's not clear whether we WANT to do an update if the re-use is set
 	// to true, since that is basically an upgrade operation.
-	if len(toBeAdopted) == 0 {
+	if len(toBeAdopted) == 0 && len(resources) > 0 {
 		if _, err := i.cfg.KubeClient.Create(resources); err != nil {
 			return i.failRelease(rel, err)
 		}
-	} else {
+	} else if len(resources) > 0 {
 		if _, err := i.cfg.KubeClient.Update(toBeAdopted, resources, false); err != nil {
 			return i.failRelease(rel, err)
 		}

pkg/action/uninstall.go

@@ -169,6 +169,7 @@ func joinErrors(errs []error) string {
 
 // deleteRelease deletes the release and returns manifests that were kept in the deletion process
 func (u *Uninstall) deleteRelease(rel *release.Release) (string, []error) {
+	var errs []error
 	caps, err := u.cfg.getCapabilities()
 	if err != nil {
 		return rel.Manifest, []error{errors.Wrap(err, "could not get apiVersions from Kubernetes")}
@@ -194,11 +195,13 @@ func (u *Uninstall) deleteRelease(rel *release.Release) (string, []error) {
 	for _, file := range filesToDelete {
 		builder.WriteString("\n---\n" + file.Content)
 	}
+
 	resources, err := u.cfg.KubeClient.Build(strings.NewReader(builder.String()), false)
 	if err != nil {
 		return "", []error{errors.Wrap(err, "unable to build kubernetes objects for delete")}
 	}
-
-	_, errs := u.cfg.KubeClient.Delete(resources)
+	if len(resources) > 0 {
+		_, errs = u.cfg.KubeClient.Delete(resources)
+	}
 	return kept, errs
 }