Introduce --disable-fetching-api-versions for install and upgrade

Signed-off-by: Eric Latham <ericoliverlatham@gmail.com>

cmd/helm/install.go

@@ -200,6 +200,7 @@ func addInstallFlags(cmd *cobra.Command, f *pflag.FlagSet, client *action.Instal
 	f.StringToStringVarP(&client.Labels, "labels", "l", nil, "Labels that would be added to release metadata. Should be divided by comma.")
 	f.BoolVar(&client.EnableDNS, "enable-dns", false, "enable DNS lookups when rendering templates")
 	f.BoolVar(&client.HideNotes, "hide-notes", false, "if set, do not show notes in install output. Does not affect presence in chart metadata")
+	f.BoolVar(&client.DisableFetchingAPIVersions, "disable-fetching-api-versions", false, "if set, the installation process will populate the built-in Capabilities.APIVersions template object with a default version set instead of fetching the full set from the Kubernetes API server")
 	addValueOptionsFlags(f, valueOpts)
 	addChartPathOptionsFlags(f, &client.ChartPathOptions)
 

cmd/helm/upgrade.go

@@ -150,6 +150,7 @@ func newUpgradeCmd(cfg *action.Configuration, out io.Writer) *cobra.Command {
 					instClient.Labels = client.Labels
 					instClient.EnableDNS = client.EnableDNS
 					instClient.HideSecret = client.HideSecret
+					instClient.DisableFetchingAPIVersions = client.DisableFetchingAPIVersions
 
 					if isReleaseUninstalled(versions) {
 						instClient.Replace = true
@@ -278,6 +279,7 @@ func newUpgradeCmd(cfg *action.Configuration, out io.Writer) *cobra.Command {
 	f.StringVar(&client.Description, "description", "", "add a custom description")
 	f.BoolVar(&client.DependencyUpdate, "dependency-update", false, "update dependencies if they are missing before installing the chart")
 	f.BoolVar(&client.EnableDNS, "enable-dns", false, "enable DNS lookups when rendering templates")
+	f.BoolVar(&client.DisableFetchingAPIVersions, "disable-fetching-api-versions", false, "if set, the upgrade process will populate the built-in Capabilities.APIVersions template object with a default version set instead of fetching the full set from the Kubernetes API server")
 	addChartPathOptionsFlags(f, &client.ChartPathOptions)
 	addValueOptionsFlags(f, valueOpts)
 	bindOutputFlag(cmd, &outfmt)

pkg/action/action.go

@@ -103,11 +103,11 @@ type Configuration struct {
 // TODO: As part of the refactor the duplicate code in cmd/helm/template.go should be removed
 //
 //	This code has to do with writing files to disk.
-func (cfg *Configuration) renderResources(ch *chart.Chart, values chartutil.Values, releaseName, outputDir string, subNotes, useReleaseName, includeCrds bool, pr postrender.PostRenderer, interactWithRemote, enableDNS, hideSecret bool) ([]*release.Hook, *bytes.Buffer, string, error) {
+func (cfg *Configuration) renderResources(ch *chart.Chart, values chartutil.Values, releaseName, outputDir string, subNotes, useReleaseName, includeCrds bool, pr postrender.PostRenderer, interactWithRemote, enableDNS, hideSecret, fetchApiVersions bool) ([]*release.Hook, *bytes.Buffer, string, error) {
 	hs := []*release.Hook{}
 	b := bytes.NewBuffer(nil)
 
-	caps, err := cfg.getCapabilities()
+	caps, err := cfg.getCapabilities(fetchApiVersions)
 	if err != nil {
 		return hs, b, "", err
 	}
@@ -243,7 +243,7 @@ type RESTClientGetter interface {
 type DebugLog func(format string, v ...interface{})
 
 // capabilities builds a Capabilities from discovery information.
-func (cfg *Configuration) getCapabilities() (*chartutil.Capabilities, error) {
+func (cfg *Configuration) getCapabilities(fetchApiVersions bool) (*chartutil.Capabilities, error) {
 	if cfg.Capabilities != nil {
 		return cfg.Capabilities, nil
 	}
@@ -262,7 +262,9 @@ func (cfg *Configuration) getCapabilities() (*chartutil.Capabilities, error) {
 	// We trap that error here and print a warning. But since the discovery client continues
 	// building the API object, it is correctly populated with all valid APIs.
 	// See https://github.com/kubernetes/kubernetes/issues/72051#issuecomment-521157642
-	apiVersions, err := GetVersionSet(dc)
+	var apiVersions chartutil.VersionSet
+	if fetchApiVersions {
+		apiVersions, err = GetVersionSet(dc)
 		if err != nil {
 			if discovery.IsGroupDiscoveryFailedError(err) {
 				cfg.Log("WARNING: The Kubernetes server has an orphaned API service. Server reports: %s", err)
@@ -271,6 +273,10 @@ func (cfg *Configuration) getCapabilities() (*chartutil.Capabilities, error) {
 				return nil, errors.Wrap(err, "could not get apiVersions from Kubernetes")
 			}
 		}
+	} else {
+		cfg.Log("WARNING: Fetching Kubernetes server-supported API versions is disabled; built-in template object Capabilities.APIVersions will contain the default version set")
+		apiVersions = chartutil.DefaultVersionSet
+	}
 
 	cfg.Capabilities = &chartutil.Capabilities{
 		APIVersions: apiVersions,

pkg/action/install.go

@@ -112,6 +112,8 @@ type Install struct {
 	PostRenderer   postrender.PostRenderer
 	// Lock to control raceconditions when the process receives a SIGTERM
 	Lock sync.Mutex
+	// DisableFetchingAPIVersions controls whether Capabilities.APIVersions is fetched from the API server
+	DisableFetchingAPIVersions bool
 }
 
 // ChartPathOptions captures common options used for controlling chart paths
@@ -284,7 +286,7 @@ func (i *Install) RunWithContext(ctx context.Context, chrt *chart.Chart, vals ma
 	// the user doesn't have to specify both
 	i.Wait = i.Wait || i.Atomic
 
-	caps, err := i.cfg.getCapabilities()
+	caps, err := i.cfg.getCapabilities(!i.DisableFetchingAPIVersions)
 	if err != nil {
 		return nil, err
 	}
@@ -310,7 +312,7 @@ func (i *Install) RunWithContext(ctx context.Context, chrt *chart.Chart, vals ma
 	rel := i.createRelease(chrt, vals, i.Labels)
 
 	var manifestDoc *bytes.Buffer
-	rel.Hooks, manifestDoc, rel.Info.Notes, err = i.cfg.renderResources(chrt, valuesToRender, i.ReleaseName, i.OutputDir, i.SubNotes, i.UseReleaseName, i.IncludeCRDs, i.PostRenderer, interactWithRemote, i.EnableDNS, i.HideSecret)
+	rel.Hooks, manifestDoc, rel.Info.Notes, err = i.cfg.renderResources(chrt, valuesToRender, i.ReleaseName, i.OutputDir, i.SubNotes, i.UseReleaseName, i.IncludeCRDs, i.PostRenderer, interactWithRemote, i.EnableDNS, i.HideSecret, !i.DisableFetchingAPIVersions)
 	// Even for errors, attach this if available
 	if manifestDoc != nil {
 		rel.Manifest = manifestDoc.String()

pkg/action/uninstall.go

@@ -196,7 +196,7 @@ func joinErrors(errs []error) string {
 // deleteRelease deletes the release and returns list of delete resources and manifests that were kept in the deletion process
 func (u *Uninstall) deleteRelease(rel *release.Release) (kube.ResourceList, string, []error) {
 	var errs []error
-	caps, err := u.cfg.getCapabilities()
+	caps, err := u.cfg.getCapabilities(true)
 	if err != nil {
 		return nil, rel.Manifest, []error{errors.Wrap(err, "could not get apiVersions from Kubernetes")}
 	}

pkg/action/upgrade.go

@@ -115,6 +115,8 @@ type Upgrade struct {
 	Lock sync.Mutex
 	// Enable DNS lookups when rendering templates
 	EnableDNS bool
+	// DisableFetchingAPIVersions controls whether Capabilities.APIVersions is fetched from the API server
+	DisableFetchingAPIVersions bool
 }
 
 type resultMessage struct {
@@ -254,7 +256,7 @@ func (u *Upgrade) prepareUpgrade(name string, chart *chart.Chart, vals map[strin
 		IsUpgrade: true,
 	}
 
-	caps, err := u.cfg.getCapabilities()
+	caps, err := u.cfg.getCapabilities(!u.DisableFetchingAPIVersions)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -269,7 +271,7 @@ func (u *Upgrade) prepareUpgrade(name string, chart *chart.Chart, vals map[strin
 		interactWithRemote = true
 	}
 
-	hooks, manifestDoc, notesTxt, err := u.cfg.renderResources(chart, valuesToRender, "", "", u.SubNotes, false, false, u.PostRenderer, interactWithRemote, u.EnableDNS, u.HideSecret)
+	hooks, manifestDoc, notesTxt, err := u.cfg.renderResources(chart, valuesToRender, "", "", u.SubNotes, false, false, u.PostRenderer, interactWithRemote, u.EnableDNS, u.HideSecret, !u.DisableFetchingAPIVersions)
 	if err != nil {
 		return nil, nil, err
 	}