fix(helm): add --devel flag to allow dev releases again

2.4.0 stopped installing development versions by default. This allows
the user to re-enable that support by setting --devel.

Closes helm#2407

cmd/helm/fetch.go

@@ -61,6 +61,8 @@ type fetchCmd struct {
 	keyFile  string
 	caFile   string
 
+	devel bool
+
 	out io.Writer
 }
 
@@ -75,6 +77,12 @@ func newFetchCmd(out io.Writer) *cobra.Command {
 			if len(args) == 0 {
 				return fmt.Errorf("This command needs at least one argument, url or repo/name of the chart.")
 			}
+
+			if fch.version == "" && fch.devel {
+				debug("setting version to >0.0.0-a")
+				fch.version = ">0.0.0-a"
+			}
+
 			for i := 0; i < len(args); i++ {
 				fch.chartRef = args[i]
 				if err := fch.run(); err != nil {
@@ -97,6 +105,7 @@ func newFetchCmd(out io.Writer) *cobra.Command {
 	f.StringVar(&fch.certFile, "cert-file", "", "identify HTTPS client using this SSL certificate file")
 	f.StringVar(&fch.keyFile, "key-file", "", "identify HTTPS client using this SSL key file")
 	f.StringVar(&fch.caFile, "ca-file", "", "verify certificates of HTTPS-enabled servers using this CA bundle")
+	f.BoolVar(&fch.devel, "devel", false, "use development versions, too. Equivalent to version '>0.0.0-a'. If --version is set, this is ignored.")
 
 	return cmd
 }

cmd/helm/install.go

@@ -117,6 +117,7 @@ type installCmd struct {
 	timeout      int64
 	wait         bool
 	repoURL      string
+	devel        bool
 
 	certFile string
 	keyFile  string
@@ -155,6 +156,13 @@ func newInstallCmd(c helm.Interface, out io.Writer) *cobra.Command {
 			if err := checkArgsLength(len(args), "chart name"); err != nil {
 				return err
 			}
+
+			debug("Original chart version: %q", inst.version)
+			if inst.version == "" && inst.devel {
+				debug("setting version to >0.0.0-a")
+				inst.version = ">0.0.0-a"
+			}
+
 			cp, err := locateChartPath(inst.repoURL, args[0], inst.version, inst.verify, inst.keyring,
 				inst.certFile, inst.keyFile, inst.caFile)
 			if err != nil {
@@ -184,6 +192,7 @@ func newInstallCmd(c helm.Interface, out io.Writer) *cobra.Command {
 	f.StringVar(&inst.certFile, "cert-file", "", "identify HTTPS client using this SSL certificate file")
 	f.StringVar(&inst.keyFile, "key-file", "", "identify HTTPS client using this SSL key file")
 	f.StringVar(&inst.caFile, "ca-file", "", "verify certificates of HTTPS-enabled servers using this CA bundle")
+	f.BoolVar(&inst.devel, "devel", false, "use development versions, too. Equivalent to version '>0.0.0-a'. If --version is set, this is ignored.")
 
 	return cmd
 }

cmd/helm/upgrade.go

@@ -75,6 +75,7 @@ type upgradeCmd struct {
 	reuseValues  bool
 	wait         bool
 	repoURL      string
+	devel        bool
 
 	certFile string
 	keyFile  string
@@ -98,6 +99,11 @@ func newUpgradeCmd(client helm.Interface, out io.Writer) *cobra.Command {
 				return err
 			}
 
+			if upgrade.version == "" && upgrade.devel {
+				debug("setting version to >0.0.0-a")
+				upgrade.version = ">0.0.0-a"
+			}
+
 			upgrade.release = args[0]
 			upgrade.chart = args[1]
 			upgrade.client = ensureHelmClient(upgrade.client)
@@ -126,6 +132,7 @@ func newUpgradeCmd(client helm.Interface, out io.Writer) *cobra.Command {
 	f.StringVar(&upgrade.certFile, "cert-file", "", "identify HTTPS client using this SSL certificate file")
 	f.StringVar(&upgrade.keyFile, "key-file", "", "identify HTTPS client using this SSL key file")
 	f.StringVar(&upgrade.caFile, "ca-file", "", "verify certificates of HTTPS-enabled servers using this CA bundle")
+	f.BoolVar(&upgrade.devel, "devel", false, "use development versions, too. Equivalent to version '>0.0.0-a'. If --version is set, this is ignored.")
 
 	f.MarkDeprecated("disable-hooks", "use --no-hooks instead")
 

pkg/downloader/chart_downloader.go

@@ -202,7 +202,7 @@ func (c *ChartDownloader) ResolveChartVersion(ref, version string) (*url.URL, ge
 
 	cv, err := i.Get(chartName, version)
 	if err != nil {
-		return u, r.Client, fmt.Errorf("chart %q not found in %s index. (try 'helm repo update'). %s", chartName, r.Config.Name, err)
+		return u, r.Client, fmt.Errorf("chart %q matching %s not found in %s index. (try 'helm repo update'). %s", chartName, version, r.Config.Name, err)
 	}
 
 	if len(cv.URLs) == 0 {