Merge pull request #779 from sttts/sttts-kcp-logicalcluster-kubectl-k…

…cp-create-context

6. kubectl-kcp: add create-context command

pkg/cliplugins/workspace/cmd/cmd.go

@@ -49,6 +49,12 @@ var (
 
 	# create a workspace and immediately enter it
 	%[1]s workspace create my-workspace --use
+
+	# create a context with the current workspace, e.g. root:default:my-workspace
+	%[1]s workspace create-context
+
+	# create a context with the current workspace, named context-name
+	%[1]s workspace create-context context-name
 `
 )
 
@@ -78,7 +84,7 @@ func NewCmdWorkspace(streams genericclioptions.IOStreams) (*cobra.Command, error
 
 	cmd := &cobra.Command{
 		Aliases:          []string{"ws", "workspaces"},
-		Use:              "workspace [list|create|<workspace>|..|-|<root:absolute:workspace>]",
+		Use:              "workspace [list|create|create-context|<workspace>|..|-|<root:absolute:workspace>]",
 		Short:            "Manages KCP workspaces",
 		Example:          fmt.Sprintf(workspaceExample, "kubectl kcp"),
 		SilenceUsage:     true,
@@ -143,15 +149,11 @@ func NewCmdWorkspace(streams genericclioptions.IOStreams) (*cobra.Command, error
 			if err := opts.Validate(); err != nil {
 				return err
 			}
-
 			kubeconfig, err := plugin.NewKubeConfig(opts)
 			if err != nil {
 				return err
 			}
-			if err := kubeconfig.CreateWorkspace(cmd.Context(), args[0], workspaceType, ignoreExisting, enterAfterCreation, time.Minute); err != nil {
-				return err
-			}
-			return nil
+			return kubeconfig.CreateWorkspace(cmd.Context(), args[0], workspaceType, ignoreExisting, enterAfterCreation, time.Minute)
 		},
 	}
 	createCmd.Flags().StringVar(&workspaceType, "type", "", "A workspace type (default: Universal)")
@@ -162,6 +164,35 @@ func NewCmdWorkspace(streams genericclioptions.IOStreams) (*cobra.Command, error
 		return nil, err
 	}
 
+	var overwriteContext bool
+	createContextCmd := &cobra.Command{
+		Use:          "create-context [<context-name>] [--overwrite]",
+		Short:        "Create a kubeconfig context for the current workspace",
+		Example:      "kcp workspace create-context",
+		SilenceUsage: true,
+		RunE: func(c *cobra.Command, args []string) error {
+			if err := opts.Validate(); err != nil {
+				return err
+			}
+			kubeconfig, err := plugin.NewKubeConfig(opts)
+			if err != nil {
+				return err
+			}
+
+			if len(args) > 1 {
+				return cmd.Help()
+			}
+
+			arg := ""
+			if len(args) == 1 {
+				arg = args[0]
+			}
+
+			return kubeconfig.CreateContext(cmd.Context(), arg, overwriteContext)
+		},
+	}
+	createContextCmd.Flags().BoolVar(&overwriteContext, "overwrite", overwriteContext, "Overwrite the context if it already exists")
+
 	deleteCmd := &cobra.Command{
 		Use:          "delete",
 		Short:        "Replaced with \"kubectl delete workspace <workspace-name>\"",
@@ -177,6 +208,7 @@ func NewCmdWorkspace(streams genericclioptions.IOStreams) (*cobra.Command, error
 	cmd.AddCommand(currentCmd)
 	cmd.AddCommand(listCmd)
 	cmd.AddCommand(createCmd)
+	cmd.AddCommand(createContextCmd)
 	cmd.AddCommand(deleteCmd)
 	return cmd, nil
 }

pkg/cliplugins/workspace/plugin/kubeconfig.go

@@ -118,7 +118,7 @@ func (kc *KubeConfig) UseWorkspace(ctx context.Context, name string) error {
 	// Store the currentContext content for later to set as previous context
 	currentContext, found := kc.startingConfig.Contexts[kc.currentContext]
 	if !found {
-		return fmt.Errorf("current %q context not found", currentContext)
+		return fmt.Errorf("current %q context not found", kc.currentContext)
 	}
 
 	var newServerHost, workspaceType string
@@ -253,7 +253,7 @@ func (kc *KubeConfig) CurrentWorkspace(ctx context.Context) error {
 func (kc *KubeConfig) currentWorkspace(ctx context.Context, host, workspaceType string) error {
 	_, clusterName, err := parseClusterURL(host)
 	if err != nil {
-		_, err = fmt.Fprintf(kc.Out, "Current workspace is the URL %q\n", host)
+		_, err = fmt.Fprintf(kc.Out, "Current workspace is the URL %q.\n", host)
 		return err
 	}
 
@@ -274,7 +274,7 @@ func (kc *KubeConfig) currentWorkspace(ctx context.Context, host, workspaceType
 	if workspaceName != workspacePrettyName {
 		message += fmt.Sprintf(" aliased as %q", workspacePrettyName)
 	}
-	_, err = fmt.Fprintln(kc.Out, message)
+	_, err = fmt.Fprintln(kc.Out, message+".")
 	return err
 }
 
@@ -406,3 +406,55 @@ func (kc *KubeConfig) ListWorkspaces(ctx context.Context, opts *Options) error {
 
 	return printer.PrintObj(table, opts.Out)
 }
+
+func (kc *KubeConfig) CreateContext(ctx context.Context, name string, overwrite bool) error {
+	config, err := clientcmd.NewDefaultClientConfig(*kc.startingConfig, nil).RawConfig()
+	if err != nil {
+		return err
+	}
+	currentContext, ok := config.Contexts[config.CurrentContext]
+	if !ok {
+		return fmt.Errorf("current context %q is not found in kubeconfig", config.CurrentContext)
+	}
+	currentCluster, ok := config.Clusters[currentContext.Cluster]
+	if !ok {
+		return fmt.Errorf("current cluster %q is not found in kubeconfig", currentContext.Cluster)
+	}
+	_, currentClusterName, err := parseClusterURL(currentCluster.Server)
+	if err != nil {
+		return fmt.Errorf("current URL %q does not point to cluster workspace", currentCluster.Server)
+	}
+
+	if name == "" {
+		name = currentClusterName.String()
+	}
+
+	_, existedBefore := kc.startingConfig.Contexts[name]
+	if existedBefore && !overwrite {
+		return fmt.Errorf("context %q already exists in kubeconfig, use --overwrite to update it", name)
+	}
+
+	newKubeConfig := kc.startingConfig.DeepCopy()
+	newCluster := *currentCluster
+	newKubeConfig.Clusters[name] = &newCluster
+	newContext := *currentContext
+	newContext.Cluster = name
+	newKubeConfig.Contexts[name] = &newContext
+	newKubeConfig.CurrentContext = name
+
+	if err := kc.modifyConfig(newKubeConfig); err != nil {
+		return err
+	}
+
+	if existedBefore {
+		if kc.startingConfig.CurrentContext == name {
+			fmt.Fprintf(kc.Out, "Updated context %q.\n", name) // nolint: errcheck
+		} else {
+			fmt.Fprintf(kc.Out, "Updated context %q and switched to it.\n", name) // nolint:	errcheck
+		}
+	} else {
+		fmt.Fprintf(kc.Out, "Created context %q and switched to it.\n", name) // nolint: errcheck
+	}
+
+	return nil
+}