makisu pull: add support for --registry-config

This is useful to authenticate with the registry when pulling images.

bin/makisu/cmd/pull.go

@@ -20,18 +20,19 @@ import (
 type pullCmd struct {
 	*cobra.Command
 
-	registry string
-	tag      string
-	cacerts  string
-	extract  string
+	registryConfig string
+	registry       string
+	tag            string
+	cacerts        string
+	extract        string
 }
 
 func getPullCmd() *pullCmd {
 	pullCmd := &pullCmd{
 		Command: &cobra.Command{
-			Use: "pull --dest <destination of rootfs> <image repository>",
+			Use:                   "pull --dest <destination of rootfs> <image repository>",
 			DisableFlagsInUseLine: true,
-			Short: "Pull docker image from registry into the storage directory of makisu.",
+			Short:                 "Pull docker image from registry into the storage directory of makisu.",
 		},
 	}
 	pullCmd.Args = func(cmd *cobra.Command, args []string) error {
@@ -44,6 +45,7 @@ func getPullCmd() *pullCmd {
 		pullCmd.Pull(args[0])
 	}
 
+	pullCmd.PersistentFlags().StringVar(&pullCmd.registryConfig, "registry-config", "", "Set build-time variables")
 	pullCmd.PersistentFlags().StringVar(&pullCmd.registry, "registry", "index.docker.io", "The registry to pull the image from.")
 	pullCmd.PersistentFlags().StringVar(&pullCmd.tag, "tag", "latest", "The tag of the image to pull.")
 	pullCmd.PersistentFlags().StringVar(&pullCmd.cacerts, "cacerts", "/etc/ssl/certs", "The location of the CA certs to use for TLS authentication with the registry.")
@@ -53,6 +55,10 @@ func getPullCmd() *pullCmd {
 }
 
 func (cmd *pullCmd) Pull(repository string) {
+	if err := initRegistryConfig(cmd.registryConfig); err != nil {
+		panic(fmt.Errorf("failed to initialize registry configuration: %s", err))
+	}
+
 	store, err := storage.NewImageStore("/tmp/makisu-storage")
 	if err != nil {
 		panic(err)