Allow customization of API Versions when using Helm Template with --api-versions or -a

Signed-off-by: Bhargav Nookala <nooknb@gmail.com>

cmd/helm/template.go

@@ -75,6 +75,7 @@ type templateCmd struct {
 	releaseIsUpgrade bool
 	renderFiles      []string
 	kubeVersion      string
+	apiVersions      []string
 	outputDir        string
 }
 
@@ -104,6 +105,7 @@ func newTemplateCmd(out io.Writer) *cobra.Command {
 	f.StringArrayVar(&t.fileValues, "set-file", []string{}, "Set values from respective files specified via the command line (can specify multiple or separate values with commas: key1=path1,key2=path2)")
 	f.StringVar(&t.nameTemplate, "name-template", "", "Specify template used to name the release")
 	f.StringVar(&t.kubeVersion, "kube-version", defaultKubeVersion, "Kubernetes version used as Capabilities.KubeVersion.Major/Minor")
+	f.StringArrayVarP(&t.apiVersions, "api-versions", "a", []string{}, "Kubernetes api versions used for Capabilities.APIVersions")
 	f.StringVar(&t.outputDir, "output-dir", "", "Writes the executed templates to files in output-dir instead of stdout")
 
 	return cmd
@@ -167,6 +169,7 @@ func (t *templateCmd) run(cmd *cobra.Command, args []string) error {
 			Namespace: t.namespace,
 		},
 		KubeVersion: t.kubeVersion,
+		APIVersions: t.apiVersions,
 	}
 
 	renderedTemplates, err := renderutil.Render(c, config, renderOpts)

cmd/helm/template_test.go

@@ -175,6 +175,13 @@ func TestTemplateCmd(t *testing.T) {
 			expectKey:   "subchart1/templates/service.yaml",
 			expectValue: "kube-version/major: \"1\"\n    kube-version/minor: \"6\"\n    kube-version/gitversion: \"v1.6.0\"",
 		},
+		{
+			name:        "check_kube_api_versions",
+			desc:        "verify --api-versions overrides kubernetes api versions",
+			args:        []string{subchart1ChartPath, "--api-versions", "helm.k8s.io/test"},
+			expectKey:   "subchart1/templates/service.yaml",
+			expectValue: "kube-api-version/test: v1",
+		},
 	}
 
 	for _, tt := range tests {

docs/helm/helm_template.md

@@ -24,6 +24,7 @@ helm template [flags] CHART
 ### Options
 
 ```
+  -a, --api-versions stringArray   Kubernetes api versions used for Capabilities.APIVersions
   -x, --execute stringArray        Only execute the given templates
   -h, --help                       help for template
       --is-upgrade                 Set .Release.IsUpgrade instead of .Release.IsInstall
@@ -55,4 +56,4 @@ helm template [flags] CHART
 
 * [helm](helm.md)	 - The Helm package manager for Kubernetes.
 
-###### Auto generated by spf13/cobra on 17-Jun-2019
+###### Auto generated by spf13/cobra on 3-Oct-2019

pkg/chartutil/testdata/subpop/charts/subchart1/templates/service.yaml

@@ -11,6 +11,9 @@ metadata:
     kube-version/major: "{{ .Capabilities.KubeVersion.Major }}"
     kube-version/minor: "{{ .Capabilities.KubeVersion.Minor }}"
     kube-version/gitversion: "v{{ .Capabilities.KubeVersion.Major }}.{{ .Capabilities.KubeVersion.Minor }}.0"
+{{ if .Capabilities.APIVersions.Has "helm.k8s.io/test" }}
+    kube-api-version/test: v1
+{{ end }}
 spec:
   type: {{ .Values.service.type }}
   ports:

pkg/renderutil/render.go

@@ -31,6 +31,7 @@ import (
 type Options struct {
 	ReleaseOptions chartutil.ReleaseOptions
 	KubeVersion    string
+	APIVersions    []string
 }
 
 // Render chart templates locally and display the output.
@@ -79,6 +80,10 @@ func Render(c *chart.Chart, config *chart.Config, opts Options) (map[string]stri
 		caps.KubeVersion.GitVersion = fmt.Sprintf("v%d.%d.0", kv.Major(), kv.Minor())
 	}
 
+	if len(opts.APIVersions) > 0 {
+		caps.APIVersions = chartutil.NewVersionSet(append(opts.APIVersions, "v1")...)
+	}
+
 	vals, err := chartutil.ToRenderValuesCaps(c, config, opts.ReleaseOptions, caps)
 	if err != nil {
 		return nil, err