ctr: add commands package with shared utility functions

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

cmd/ctr/commands/commands.go

@@ -0,0 +1,84 @@
+package commands
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/containerd/containerd"
+	"github.com/urfave/cli"
+)
+
+var (
+	// SnapshotterFlags are cli flags specifying snapshotter names
+	SnapshotterFlags = []cli.Flag{
+		cli.StringFlag{
+			Name:  "snapshotter",
+			Usage: "snapshotter name. Empty value stands for the daemon default value.",
+			Value: containerd.DefaultSnapshotter,
+		},
+	}
+
+	// LabelFlag is a cli flag specifying labels
+	LabelFlag = cli.StringSliceFlag{
+		Name:  "label",
+		Usage: "labels to attach to the image",
+	}
+
+	// RegistryFlags are cli flags specifying registry options
+	RegistryFlags = []cli.Flag{
+		cli.BoolFlag{
+			Name:  "skip-verify,k",
+			Usage: "skip SSL certificate validation",
+		},
+		cli.BoolFlag{
+			Name:  "plain-http",
+			Usage: "allow connections using plain HTTP",
+		},
+		cli.StringFlag{
+			Name:  "user,u",
+			Usage: "user[:password] Registry user and password",
+		},
+		cli.StringFlag{
+			Name:  "refresh",
+			Usage: "refresh token for authorization server",
+		},
+	}
+)
+
+// ObjectWithLabelArgs returns the first arg and a LabelArgs object
+func ObjectWithLabelArgs(clicontext *cli.Context) (string, map[string]string) {
+	var (
+		first        = clicontext.Args().First()
+		labelStrings = clicontext.Args().Tail()
+	)
+
+	return first, LabelArgs(labelStrings)
+}
+
+// LabelArgs returns a map of label key,value pairs
+func LabelArgs(labelStrings []string) map[string]string {
+	labels := make(map[string]string, len(labelStrings))
+	for _, label := range labelStrings {
+		parts := strings.SplitN(label, "=", 2)
+		key := parts[0]
+		value := "true"
+		if len(parts) > 1 {
+			value = parts[1]
+		}
+
+		labels[key] = value
+	}
+
+	return labels
+}
+
+// PrintAsJSON prints input in JSON format
+func PrintAsJSON(x interface{}) {
+	b, err := json.MarshalIndent(x, "", "    ")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "can't marshal %+v as a JSON string: %v\n", x, err)
+	}
+	fmt.Println(string(b))
+}

cmd/ctr/content.go

@@ -10,6 +10,7 @@ import (
 	"text/tabwriter"
 	"time"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
@@ -212,7 +213,7 @@ var (
 		Description: `Labels blobs in the content store`,
 		Flags:       []cli.Flag{},
 		Action: func(context *cli.Context) error {
-			object, labels := objectWithLabelArgs(context)
+			object, labels := commands.ObjectWithLabelArgs(context)
 			client, ctx, cancel, err := newClient(context)
 			if err != nil {
 				return err

cmd/ctr/fetch.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
@@ -39,7 +40,7 @@ not use this implementation as a guide. The end goal should be having metadata,
 content and snapshots ready for a direct use via the 'ctr run'.
 
 Most of this is experimental and there are few leaps to make this work.`,
-	Flags: append(registryFlags, labelFlag),
+	Flags: append(commands.RegistryFlags, commands.LabelFlag),
 	Action: func(clicontext *cli.Context) error {
 		var (
 			ref = clicontext.Args().First()
@@ -82,7 +83,7 @@ func fetch(ref string, cliContext *cli.Context) (containerd.Image, error) {
 	})
 
 	log.G(pctx).WithField("image", ref).Debug("fetching")
-	labels := labelArgs(cliContext.StringSlice("label"))
+	labels := commands.LabelArgs(cliContext.StringSlice("label"))
 	img, err := client.Pull(pctx, ref,
 		containerd.WithPullLabels(labels),
 		containerd.WithResolver(resolver),

cmd/ctr/fetchobject.go

@@ -4,6 +4,7 @@ import (
 	"io"
 	"os"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/log"
 	"github.com/urfave/cli"
 )
@@ -17,7 +18,7 @@ var fetchObjectCommand = cli.Command{
 	Usage:       "retrieve objects from a remote",
 	ArgsUsage:   "[flags] <remote> <object> [<hint>, ...]",
 	Description: `Fetch objects by identifier from a remote.`,
-	Flags:       registryFlags,
+	Flags:       commands.RegistryFlags,
 	Action: func(context *cli.Context) error {
 		var (
 			ref = context.Args().First()

cmd/ctr/images.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"text/tabwriter"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/log"
@@ -127,7 +128,7 @@ var imagesSetLabelsCommand = cli.Command{
 	Action: func(context *cli.Context) error {
 		var (
 			replaceAll   = context.Bool("replace-all")
-			name, labels = objectWithLabelArgs(context)
+			name, labels = commands.ObjectWithLabelArgs(context)
 		)
 		client, ctx, cancel, err := newClient(context)
 		if err != nil {

cmd/ctr/import.go

@@ -6,6 +6,7 @@ import (
 	"os"
 
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/log"
 	"github.com/urfave/cli"
 )
@@ -21,14 +22,14 @@ var imagesImportCommand = cli.Command{
 			Value: "",
 			Usage: "reference object e.g. tag@digest (default: use the object specified in ref)",
 		},
-		labelFlag,
+		commands.LabelFlag,
 	},
 	Action: func(context *cli.Context) error {
 		var (
 			ref       = context.Args().First()
 			in        = context.Args().Get(1)
 			refObject = context.String("ref-object")
-			labels    = labelArgs(context.StringSlice("label"))
+			labels    = commands.LabelArgs(context.StringSlice("label"))
 		)
 		client, ctx, cancel, err := newClient(context)
 		if err != nil {

cmd/ctr/info.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
 )
@@ -27,7 +28,7 @@ var containerInfoCommand = cli.Command{
 		if err != nil {
 			return err
 		}
-		printAsJSON(info)
+		commands.PrintAsJSON(info)
 
 		return nil
 	},

cmd/ctr/labels.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/urfave/cli"
 )
 
@@ -15,7 +16,7 @@ var containersSetLabelsCommand = cli.Command{
 	Description: "Set and clear labels for a container.",
 	Flags:       []cli.Flag{},
 	Action: func(context *cli.Context) error {
-		containerID, labels := objectWithLabelArgs(context)
+		containerID, labels := commands.ObjectWithLabelArgs(context)
 		if containerID == "" {
 			return errors.New("please specify a container")
 		}

cmd/ctr/namespaces.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"text/tabwriter"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
 	"github.com/pkg/errors"
@@ -30,7 +31,7 @@ var namespacesCreateCommand = cli.Command{
 	ArgsUsage:   "[flags] <name> [<key>=<value]",
 	Description: "Create a new namespace. It must be unique.",
 	Action: func(context *cli.Context) error {
-		namespace, labels := objectWithLabelArgs(context)
+		namespace, labels := commands.ObjectWithLabelArgs(context)
 		if namespace == "" {
 			return errors.New("please specify a namespace")
 		}
@@ -51,7 +52,7 @@ var namespacesSetLabelsCommand = cli.Command{
 	Description: "Set and clear labels for a namespace.",
 	Flags:       []cli.Flag{},
 	Action: func(context *cli.Context) error {
-		namespace, labels := objectWithLabelArgs(context)
+		namespace, labels := commands.ObjectWithLabelArgs(context)
 		if namespace == "" {
 			return errors.New("please specify a namespace")
 		}

cmd/ctr/pull.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/log"
 	"github.com/urfave/cli"
 )
@@ -20,7 +21,7 @@ command. As part of this process, we do the following:
 2. Prepare the snapshot filesystem with the pulled resources.
 3. Register metadata for the image.
 `,
-	Flags: append(registryFlags, append(snapshotterFlags, labelFlag)...),
+	Flags: append(commands.RegistryFlags, append(commands.SnapshotterFlags, commands.LabelFlag)...),
 	Action: func(context *cli.Context) error {
 		var (
 			ref = context.Args().First()

cmd/ctr/push.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/progress"
@@ -37,7 +38,7 @@ var pushCommand = cli.Command{
 	creating the associated configuration, and creating the manifest
 	which references those resources.
 `,
-	Flags: append(registryFlags, cli.StringFlag{
+	Flags: append(commands.RegistryFlags, cli.StringFlag{
 		Name:  "manifest",
 		Usage: "digest of manifest",
 	}, cli.StringFlag{

cmd/ctr/pushobject.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/log"
 	digest "github.com/opencontainers/go-digest"
@@ -15,7 +16,7 @@ var pushObjectCommand = cli.Command{
 	Usage:       "push an object to a remote",
 	ArgsUsage:   "[flags] <remote> <object> <type>",
 	Description: `Push objects by identifier to a remote.`,
-	Flags:       registryFlags,
+	Flags:       commands.RegistryFlags,
 	Action: func(context *cli.Context) error {
 		var (
 			ref    = context.Args().Get(0)

cmd/ctr/rootfs.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/log"
 	digest "github.com/opencontainers/go-digest"
 	"github.com/urfave/cli"
@@ -21,7 +22,7 @@ var rootfsUnpackCommand = cli.Command{
 	Name:      "unpack",
 	Usage:     "unpack applies layers from a manifest to a snapshot",
 	ArgsUsage: "[flags] <digest>",
-	Flags:     snapshotterFlags,
+	Flags:     commands.SnapshotterFlags,
 	Action: func(context *cli.Context) error {
 		dgst, err := digest.Parse(context.Args().First())
 		if err != nil {

cmd/ctr/run.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/containerd/console"
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/containers"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
@@ -100,7 +101,7 @@ var runCommand = cli.Command{
 			Name:  "detach,d",
 			Usage: "detach from the task after it has started execution",
 		},
-	}, snapshotterFlags...),
+	}, commands.SnapshotterFlags...),
 	Action: func(context *cli.Context) error {
 		var (
 			err error

cmd/ctr/run_unix.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/containerd/console"
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
@@ -76,7 +77,7 @@ func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 		opts  []containerd.SpecOpts
 		cOpts []containerd.NewContainerOpts
 	)
-	cOpts = append(cOpts, containerd.WithContainerLabels(labelArgs(context.StringSlice("label"))))
+	cOpts = append(cOpts, containerd.WithContainerLabels(commands.LabelArgs(context.StringSlice("label"))))
 	if context.Bool("rootfs") {
 		opts = append(opts, containerd.WithRootFSPath(ref))
 	} else {

cmd/ctr/run_windows.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/containerd/console"
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/containers"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
@@ -92,7 +93,7 @@ func newContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 		labelStrings = context.StringSlice("label")
 	)
 
-	labels := labelArgs(labelStrings)
+	labels := commands.LabelArgs(labelStrings)
 
 	// TODO(mlaventure): get base image once we have a snapshotter
 

cmd/ctr/shim.go

@@ -13,6 +13,7 @@ import (
 	"google.golang.org/grpc"
 
 	"github.com/containerd/console"
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	shim "github.com/containerd/containerd/linux/shim/v1"
 	"github.com/containerd/typeurl"
 	protobuf "github.com/gogo/protobuf/types"
@@ -182,7 +183,7 @@ var shimStateCommand = cli.Command{
 		if err != nil {
 			return err
 		}
-		printAsJSON(r)
+		commands.PrintAsJSON(r)
 		return nil
 	},
 }

cmd/ctr/snapshot.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"text/tabwriter"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/mount"
 	"github.com/containerd/containerd/progress"
 	"github.com/containerd/containerd/snapshot"
@@ -17,7 +18,7 @@ import (
 var snapshotCommand = cli.Command{
 	Name:  "snapshot",
 	Usage: "snapshot management",
-	Flags: snapshotterFlags,
+	Flags: commands.SnapshotterFlags,
 	Subcommands: cli.Commands{
 		listSnapshotCommand,
 		usageSnapshotCommand,
@@ -325,7 +326,7 @@ var infoSnapshotCommand = cli.Command{
 			return err
 		}
 
-		printAsJSON(info)
+		commands.PrintAsJSON(info)
 
 		return nil
 	},
@@ -338,7 +339,7 @@ var labelSnapshotCommand = cli.Command{
 	Description: `Labels snapshots in the snapshotter`,
 	Flags:       []cli.Flag{},
 	Action: func(context *cli.Context) error {
-		key, labels := objectWithLabelArgs(context)
+		key, labels := commands.ObjectWithLabelArgs(context)
 		client, ctx, cancel, err := newClient(context)
 		if err != nil {
 			return err

cmd/ctr/utils.go

@@ -5,7 +5,6 @@ import (
 	gocontext "context"
 	"crypto/tls"
 	"encoding/csv"
-	"encoding/json"
 	"fmt"
 	"net"
 	"net/http"
@@ -18,54 +17,15 @@ import (
 
 	"github.com/containerd/console"
 	"github.com/containerd/containerd"
-	"github.com/containerd/containerd/content"
-	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/namespaces"
-	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/remotes"
 	"github.com/containerd/containerd/remotes/docker"
-	"github.com/containerd/containerd/rootfs"
-	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 )
 
-var (
-	snapshotterFlags = []cli.Flag{
-		cli.StringFlag{
-			Name:  "snapshotter",
-			Usage: "snapshotter name. Empty value stands for the daemon default value.",
-			Value: containerd.DefaultSnapshotter,
-		},
-	}
-
-	labelFlag = cli.StringSliceFlag{
-		Name:  "label",
-		Usage: "labels to attach to the pulled image",
-	}
-
-	registryFlags = []cli.Flag{
-		cli.BoolFlag{
-			Name:  "skip-verify,k",
-			Usage: "skip SSL certificate validation",
-		},
-		cli.BoolFlag{
-			Name:  "plain-http",
-			Usage: "allow connections using plain HTTP",
-		},
-		cli.StringFlag{
-			Name:  "user,u",
-			Usage: "user[:password] Registry user and password",
-		},
-		cli.StringFlag{
-			Name:  "refresh",
-			Usage: "refresh token for authorization server",
-		},
-	}
-)
-
 // appContext returns the context for a command. Should only be called once per
 // command, near the start.
 //
@@ -114,39 +74,6 @@ func passwordPrompt() (string, error) {
 	return string(line), nil
 }
 
-func getImageLayers(ctx gocontext.Context, image images.Image, cs content.Store) ([]rootfs.Layer, error) {
-	p, err := content.ReadBlob(ctx, cs, image.Target.Digest)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to read manifest blob")
-	}
-
-	var manifest ocispec.Manifest
-	if err := json.Unmarshal(p, &manifest); err != nil {
-		return nil, errors.Wrap(err, "failed to unmarshal manifest")
-	}
-
-	diffIDs, err := image.RootFS(ctx, cs, platforms.Default())
-	if err != nil {
-		return nil, errors.Wrap(err, "failed to resolve rootfs")
-	}
-
-	if len(diffIDs) != len(manifest.Layers) {
-		return nil, errors.Errorf("mismatched image rootfs and manifest layers")
-	}
-
-	layers := make([]rootfs.Layer, len(diffIDs))
-	for i := range diffIDs {
-		layers[i].Diff = ocispec.Descriptor{
-			// TODO: derive media type from compressed type
-			MediaType: ocispec.MediaTypeImageLayer,
-			Digest:    diffIDs[i],
-		}
-		layers[i].Blob = manifest.Layers[i]
-	}
-
-	return layers, nil
-}
-
 // getResolver prepares the resolver from the environment and options.
 func getResolver(ctx gocontext.Context, clicontext *cli.Context) (remotes.Resolver, error) {
 	username := clicontext.String("user")
@@ -312,36 +239,3 @@ func replaceOrAppendEnvValues(defaults, overrides []string) []string {
 
 	return defaults
 }
-
-func objectWithLabelArgs(clicontext *cli.Context) (string, map[string]string) {
-	var (
-		namespace    = clicontext.Args().First()
-		labelStrings = clicontext.Args().Tail()
-	)
-
-	return namespace, labelArgs(labelStrings)
-}
-
-func labelArgs(labelStrings []string) map[string]string {
-	labels := make(map[string]string, len(labelStrings))
-	for _, label := range labelStrings {
-		parts := strings.SplitN(label, "=", 2)
-		key := parts[0]
-		value := "true"
-		if len(parts) > 1 {
-			value = parts[1]
-		}
-
-		labels[key] = value
-	}
-
-	return labels
-}
-
-func printAsJSON(x interface{}) {
-	b, err := json.MarshalIndent(x, "", "    ")
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "can't marshal %+v as a JSON string: %v\n", x, err)
-	}
-	fmt.Println(string(b))
-}