Add kubectl-accurate template list sub command.

cmd/kubectl-accurate/sub/sub.go

@@ -16,5 +16,6 @@ func newSubCmd(streams genericclioptions.IOStreams, config *genericclioptions.Co
 	cmd.AddCommand(newSubMoveCmd(streams, config))
 	cmd.AddCommand(newSubGraftCmd(streams, config))
 	cmd.AddCommand(newSubCutCmd(streams, config))
+	cmd.AddCommand(newSubListCmd(streams, config))
 	return cmd
 }

cmd/kubectl-accurate/sub/sub_list.go

@@ -0,0 +1,11 @@
+package sub
+
+import (
+	"github.com/spf13/cobra"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+)
+
+// newSubListCmd is an alias for the "kubectl-accurate list" command.
+func newSubListCmd(streams genericclioptions.IOStreams, config *genericclioptions.ConfigFlags) *cobra.Command {
+	return newListCmd(streams, config)
+}

cmd/kubectl-accurate/sub/template.go

@@ -11,6 +11,7 @@ func newTemplateCmd(streams genericclioptions.IOStreams, config *genericclioptio
 		Short: "template subcommand",
 	}
 
+	cmd.AddCommand(newTemplateListCmd(streams, config))
 	cmd.AddCommand(newTemplateSetCmd(streams, config))
 	cmd.AddCommand(newTemplateUnsetCmd(streams, config))
 	return cmd

cmd/kubectl-accurate/sub/template_list.go

@@ -0,0 +1,102 @@
+package sub
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/cybozu-go/accurate/pkg/constants"
+	"github.com/spf13/cobra"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+type templateListOpts struct {
+	streams  genericclioptions.IOStreams
+	client   client.Client
+	template string
+}
+
+func newTemplateListCmd(streams genericclioptions.IOStreams, config *genericclioptions.ConfigFlags) *cobra.Command {
+	opts := &templateListOpts{}
+
+	cmd := &cobra.Command{
+		Use:     "list [TEMPLATE]",
+		Aliases: []string{"ls"},
+		Short:   "List template namespace trees hierarchically",
+		Long: `List template namespace trees hierarchically.
+If TEMPLATE is not given, all template namespaces are shown hierarchically.
+If TEMPLATE is given, only the tree under the TEMPLATE namespace will be shown.`,
+		Args: cobra.MaximumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := opts.Fill(streams, config, args); err != nil {
+				return err
+			}
+			return opts.Run(cmd.Context())
+		},
+	}
+	return cmd
+}
+
+func (o *templateListOpts) Fill(streams genericclioptions.IOStreams, config *genericclioptions.ConfigFlags, args []string) error {
+	o.streams = streams
+	cl, err := makeClient(config)
+	if err != nil {
+		return err
+	}
+	o.client = cl
+
+	if len(args) > 0 {
+		o.template = args[0]
+	}
+
+	return nil
+}
+
+func (o *templateListOpts) Run(ctx context.Context) error {
+	if o.template != "" {
+		return o.showNS(ctx, o.template, 0)
+	}
+
+	templates := &corev1.NamespaceList{}
+	if err := o.client.List(ctx, templates, client.MatchingLabels{constants.LabelType: constants.NSTypeTemplate}); err != nil {
+		return fmt.Errorf("failed to list the template namespaces: %w", err)
+	}
+
+	for _, ns := range templates.Items {
+		if _, ok := ns.Labels[constants.LabelTemplate]; ok {
+			continue
+		}
+
+		if err := o.showNS(ctx, ns.Name, 0); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (o *templateListOpts) showNS(ctx context.Context, name string, level int) error {
+	ns := &corev1.Namespace{}
+	if err := o.client.Get(ctx, client.ObjectKey{Name: name}, ns); err != nil {
+		return fmt.Errorf("failed to get namespace %s: %w", name, err)
+	}
+
+	subMark := " "
+	if _, ok := ns.Labels[constants.LabelTemplate]; ok {
+		subMark = "⮡"
+	}
+	fmt.Fprintf(o.streams.Out, "%*s%s%s\n", level, "", subMark, name)
+
+	children := &corev1.NamespaceList{}
+	if err := o.client.List(ctx, children, client.MatchingLabels{constants.LabelTemplate: name}); err != nil {
+		return fmt.Errorf("failed to list the instances of %s: %w", name, err)
+	}
+
+	level += indent
+	for _, child := range children.Items {
+		if err := o.showNS(ctx, child.Name, level); err != nil {
+			return err
+		}
+	}
+	return nil
+}

docs/info.md

@@ -17,14 +17,15 @@ $ kubectl accurate list
 
 ## Show all template Namespaces
 
-Use `kubectl get ns -l accurate.cybozu.com/type=template`:
+Use `kubectl accurate template list`:
 
 ```console
-$ kubectl get ns -l accurate.cybozu.com/type=template
-NAME    STATUS   AGE
-tmpl1   Active   3m45s
-tmpl2   Active   3m43s
-tmpl3   Active   3m43s
+$ kubectl accurate template list
+ template1
+ template2
+    ⮡reference1
+    ⮡reference2
+ template3
 ```
 
 ## Show the properties of a Namespace

docs/kubectl-accurate.md

@@ -70,6 +70,12 @@ Valid types are `root` or `template`.
 
 To unset the type, specify `none` as the type.
 
+### `template list [TEMPLATE]`
+
+List template namespace trees hierarchically.
+If TEMPLATE is not given, all template namespaces are shown hierarchically.
+If TEMPLATE is given, only the tree under the TEMPLATE namespace will be shown.
+
 ### `template set NS TEMPLATE`
 
 Set `TEMPLATE` namespace as the template of `NS` namespace.
@@ -109,4 +115,8 @@ The child sub-namespaces under `NS` will be moved along with it.
 
 Propagated resources with mode `update` in `NS` will be deleted.
 
+### `sub list [ROOT]`
+
+Alias for `kubectl-accurate list` command.
+
 [SubNamespace]: ./crd_subnamespace.md

e2e/e2e_test.go

@@ -244,6 +244,8 @@ var _ = Describe("kubectl accurate", func() {
 
 	It("should run other commands", func() {
 		kubectlSafe(nil, "accurate", "list")
+		kubectlSafe(nil, "accurate", "sub", "list")
+		kubectlSafe(nil, "accurate", "template", "list")
 		kubectlSafe(nil, "accurate", "ns", "describe", "tmpl1")
 	})
 })