ctr: move namespaces command

Signed-off-by: Jess Valarezo <valarezo.jessica@gmail.com>

cmd/ctr/commands/namespaces/namespaces.go

@@ -0,0 +1,156 @@
+package namespaces
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+	"text/tabwriter"
+
+	"github.com/containerd/containerd/cmd/ctr/commands"
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/log"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+)
+
+// Command is the cli command for managing namespaces
+var Command = cli.Command{
+	Name:  "namespaces",
+	Usage: "manage namespaces",
+	Subcommands: cli.Commands{
+		createCommand,
+		setLabelsCommand,
+		listCommand,
+		removeCommand,
+	},
+}
+
+var createCommand = cli.Command{
+	Name:        "create",
+	Usage:       "create a new namespace",
+	ArgsUsage:   "<name> [<key>=<value]",
+	Description: "create a new namespace. it must be unique",
+	Action: func(context *cli.Context) error {
+		namespace, labels := commands.ObjectWithLabelArgs(context)
+		if namespace == "" {
+			return errors.New("please specify a namespace")
+		}
+		client, ctx, cancel, err := commands.NewClient(context)
+		if err != nil {
+			return err
+		}
+		defer cancel()
+		namespaces := client.NamespaceService()
+		return namespaces.Create(ctx, namespace, labels)
+	},
+}
+
+var setLabelsCommand = cli.Command{
+	Name:        "label",
+	Usage:       "set and clear labels for a namespace",
+	ArgsUsage:   "<name> [<key>=<value>, ...]",
+	Description: "set and clear labels for a namespace",
+	Action: func(context *cli.Context) error {
+		namespace, labels := commands.ObjectWithLabelArgs(context)
+		if namespace == "" {
+			return errors.New("please specify a namespace")
+		}
+		client, ctx, cancel, err := commands.NewClient(context)
+		if err != nil {
+			return err
+		}
+		defer cancel()
+		namespaces := client.NamespaceService()
+		for k, v := range labels {
+			if err := namespaces.SetLabel(ctx, namespace, k, v); err != nil {
+				return err
+			}
+		}
+		return nil
+	},
+}
+
+var listCommand = cli.Command{
+	Name:        "list",
+	Aliases:     []string{"ls"},
+	Usage:       "list namespaces",
+	ArgsUsage:   "[flags]",
+	Description: "list namespaces",
+	Flags: []cli.Flag{
+		cli.BoolFlag{
+			Name:  "quiet, q",
+			Usage: "print only the namespace name",
+		},
+	},
+	Action: func(context *cli.Context) error {
+		quiet := context.Bool("quiet")
+		client, ctx, cancel, err := commands.NewClient(context)
+		if err != nil {
+			return err
+		}
+		defer cancel()
+		namespaces := client.NamespaceService()
+		nss, err := namespaces.List(ctx)
+		if err != nil {
+			return err
+		}
+
+		if quiet {
+			for _, ns := range nss {
+				fmt.Println(ns)
+			}
+			return nil
+		}
+
+		tw := tabwriter.NewWriter(os.Stdout, 1, 8, 1, ' ', 0)
+		fmt.Fprintln(tw, "NAME\tLABELS\t")
+		for _, ns := range nss {
+			labels, err := namespaces.Labels(ctx, ns)
+			if err != nil {
+				return err
+			}
+
+			var labelStrings []string
+			for k, v := range labels {
+				labelStrings = append(labelStrings, strings.Join([]string{k, v}, "="))
+			}
+			sort.Strings(labelStrings)
+
+			fmt.Fprintf(tw, "%v\t%v\t\n", ns, strings.Join(labelStrings, ","))
+		}
+		return tw.Flush()
+	},
+}
+
+var removeCommand = cli.Command{
+	Name:        "remove",
+	Aliases:     []string{"rm"},
+	Usage:       "remove one or more namespaces",
+	ArgsUsage:   "<name> [<name>, ...]",
+	Description: "remove one or more namespaces. for now, the namespace must be empty",
+	Action: func(context *cli.Context) error {
+		var exitErr error
+		client, ctx, cancel, err := commands.NewClient(context)
+		if err != nil {
+			return err
+		}
+		defer cancel()
+		namespaces := client.NamespaceService()
+		for _, target := range context.Args() {
+			if err := namespaces.Delete(ctx, target); err != nil {
+				if !errdefs.IsNotFound(err) {
+					if exitErr == nil {
+						exitErr = errors.Wrapf(err, "unable to delete %v", target)
+					}
+					log.G(ctx).WithError(err).Errorf("unable to delete %v", target)
+					continue
+				}
+
+			}
+
+			fmt.Println(target)
+		}
+		return exitErr
+	},
+}