Add compose images command

The command prints images used by created containers in services.

Signed-off-by: Jin Dong <jindon@amazon.com>

README.md

@@ -332,6 +332,7 @@ It does not necessarily mean that the corresponding features are missing in cont
     - [:whale: nerdctl compose logs](#whale-nerdctl-compose-logs)
     - [:whale: nerdctl compose build](#whale-nerdctl-compose-build)
     - [:whale: nerdctl compose down](#whale-nerdctl-compose-down)
+    - [:whale: nerdctl compose images](#whale-nerdctl-compose-images)
     - [:whale: nerdctl compose stop](#whale-nerdctl-compose-stop)
     - [:whale: nerdctl compose ps](#whale-nerdctl-compose-ps)
     - [:whale: nerdctl compose pull](#whale-nerdctl-compose-pull)
@@ -1445,6 +1446,16 @@ Flags:
 
 Unimplemented `docker-compose down` (V1) flags: `--rmi`, `--remove-orphans`, `--timeout`
 
+### :whale: nerdctl compose images
+
+List images used by created containers in services
+
+Usage: `nerdctl compose images [OPTIONS] [SERVICE...]`
+
+Flags:
+
+- :whale: `-q, --quiet`: Only show numeric image IDs
+
 ### :whale: nerdctl compose stop
 
 Stop containers in services without removing them.
@@ -1601,7 +1612,7 @@ Registry:
 - `docker search`
 
 Compose:
-- `docker-compose create|events|exec|images|pause|port|rm|scale|start|top|unpause`
+- `docker-compose create|events|exec|pause|port|rm|scale|start|top|unpause`
 
 Others:
 - `docker system df`

cmd/nerdctl/compose.go

@@ -58,6 +58,7 @@ func newComposeCommand() *cobra.Command {
 		newComposeLogsCommand(),
 		newComposeConfigCommand(),
 		newComposeBuildCommand(),
+		newComposeImagesCommand(),
 		newComposePushCommand(),
 		newComposePullCommand(),
 		newComposeDownCommand(),

cmd/nerdctl/compose_images.go

@@ -0,0 +1,190 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"sync"
+	"text/tabwriter"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/pkg/progress"
+	"github.com/containerd/containerd/snapshots"
+	"github.com/containerd/nerdctl/pkg/imgutil"
+	"github.com/containerd/nerdctl/pkg/labels"
+	"github.com/containerd/nerdctl/pkg/strutil"
+	"github.com/spf13/cobra"
+	"golang.org/x/sync/errgroup"
+)
+
+func newComposeImagesCommand() *cobra.Command {
+	var composeImagesCommand = &cobra.Command{
+		Use:           "images [flags] [SERVICE...]",
+		Short:         "List images used by created containers in services",
+		RunE:          composeImagesAction,
+		SilenceUsage:  true,
+		SilenceErrors: true,
+	}
+	composeImagesCommand.Flags().BoolP("quiet", "q", false, "Only show numeric image IDs")
+
+	return composeImagesCommand
+}
+
+func composeImagesAction(cmd *cobra.Command, args []string) error {
+	quiet, err := cmd.Flags().GetBool("quiet")
+	if err != nil {
+		return err
+	}
+
+	client, ctx, cancel, err := newClient(cmd)
+	if err != nil {
+		return err
+	}
+	defer cancel()
+
+	c, err := getComposer(cmd, client)
+	if err != nil {
+		return err
+	}
+
+	serviceNames, err := c.ServiceNames(args...)
+	if err != nil {
+		return err
+	}
+
+	containers, err := c.Containers(ctx, serviceNames...)
+	if err != nil {
+		return err
+	}
+
+	if quiet {
+		return printComposeImageIDs(ctx, containers)
+	}
+
+	snapshotter, err := cmd.Flags().GetString("snapshotter")
+	if err != nil {
+		return err
+	}
+	sn := client.SnapshotService(snapshotter)
+
+	return printComposeImages(ctx, cmd, containers, sn)
+}
+
+func printComposeImageIDs(ctx context.Context, containers []containerd.Container) error {
+	ids := []string{}
+	for _, c := range containers {
+		image, err := c.Image(ctx)
+		if err != nil {
+			return err
+		}
+		metaImage := image.Metadata()
+		id := metaImage.Target.Digest.String()
+		if !strutil.InStringSlice(ids, id) {
+			ids = append(ids, id)
+		}
+	}
+
+	for _, id := range ids {
+		// always truncate image ids.
+		fmt.Println(strings.Split(id, ":")[1][:12])
+	}
+	return nil
+}
+
+func printComposeImages(ctx context.Context, cmd *cobra.Command, containers []containerd.Container, sn snapshots.Snapshotter) error {
+	type composeImagePrintable struct {
+		ContainerName string
+		Repository    string
+		Tag           string
+		ImageID       string
+		Size          string
+	}
+
+	var (
+		imagePrintables = []composeImagePrintable{}
+		mu              sync.Mutex
+	)
+
+	eg, ctx := errgroup.WithContext(ctx)
+	for _, c := range containers {
+		c := c
+		eg.Go(func() error {
+			info, err := c.Info(ctx, containerd.WithoutRefreshedMetadata)
+			if err != nil {
+				return err
+			}
+			containerName := info.Labels[labels.Name]
+
+			image, err := c.Image(ctx)
+			if err != nil {
+				return err
+			}
+
+			size, err := unpackedImageSize(ctx, sn, image)
+			if err != nil {
+				return err
+			}
+
+			metaImage := image.Metadata()
+			repository, tag := imgutil.ParseRepoTag(metaImage.Name)
+			imageID := metaImage.Target.Digest.String()
+			if repository == "" {
+				repository = "<none>"
+			}
+			if tag == "" {
+				tag = "<none>"
+			}
+			imageID = strings.Split(imageID, ":")[1][:12]
+
+			printable := composeImagePrintable{
+				ContainerName: containerName,
+				Repository:    repository,
+				Tag:           tag,
+				ImageID:       imageID,
+				Size:          progress.Bytes(size).String(),
+			}
+
+			mu.Lock()
+			defer mu.Unlock()
+			imagePrintables = append(imagePrintables, printable)
+
+			return nil
+		})
+	}
+
+	if err := eg.Wait(); err != nil {
+		return err
+	}
+
+	w := tabwriter.NewWriter(cmd.OutOrStdout(), 4, 8, 4, ' ', 0)
+	fmt.Fprintln(w, "Container\tRepository\tTag\tImage Id\tSize")
+	for _, p := range imagePrintables {
+		if _, err := fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n",
+			p.ContainerName,
+			p.Repository,
+			p.Tag,
+			p.ImageID,
+			p.Size,
+		); err != nil {
+			return err
+		}
+	}
+
+	return w.Flush()
+}

cmd/nerdctl/compose_images_linux_test.go

@@ -0,0 +1,86 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package main
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/containerd/nerdctl/pkg/testutil"
+)
+
+func TestComposeImages(t *testing.T) {
+	base := testutil.NewBase(t)
+	var dockerComposeYAML = fmt.Sprintf(`
+version: '3.1'
+
+services:
+  wordpress:
+    image: %s
+    ports:
+      - 8080:80
+    environment:
+      WORDPRESS_DB_HOST: db
+      WORDPRESS_DB_USER: exampleuser
+      WORDPRESS_DB_PASSWORD: examplepass
+      WORDPRESS_DB_NAME: exampledb
+    volumes:
+      - wordpress:/var/www/html
+  db:
+    image: %s
+    environment:
+      MYSQL_DATABASE: exampledb
+      MYSQL_USER: exampleuser
+      MYSQL_PASSWORD: examplepass
+      MYSQL_RANDOM_ROOT_PASSWORD: '1'
+    volumes:
+      - db:/var/lib/mysql
+
+volumes:
+  wordpress:
+  db:
+`, testutil.WordpressImage, testutil.MariaDBImage)
+
+	comp := testutil.NewComposeDir(t, dockerComposeYAML)
+	defer comp.CleanUp()
+	projectName := comp.ProjectName()
+	t.Logf("projectName=%q", projectName)
+
+	base.ComposeCmd("-f", comp.YAMLFullPath(), "up", "-d").AssertOK()
+	defer base.ComposeCmd("-f", comp.YAMLFullPath(), "down", "-v").Run()
+
+	ImageAssertHandler := func(svc string, image string, exist bool) func(stdout string) error {
+		return func(stdout string) error {
+			if strings.Contains(stdout, image) != exist {
+				return fmt.Errorf("image %s from service %s: expect in output (%t), actual (%t)", image, svc, exist, !exist)
+			}
+			return nil
+		}
+	}
+
+	wordpressImageName := strings.Split(testutil.WordpressImage, ":")[0]
+	dbImageName := strings.Split(testutil.MariaDBImage, ":")[0]
+
+	// check one service image
+	base.ComposeCmd("-f", comp.YAMLFullPath(), "images", "db").AssertOutWithFunc(ImageAssertHandler("db", dbImageName, true))
+	base.ComposeCmd("-f", comp.YAMLFullPath(), "images", "db").AssertOutWithFunc(ImageAssertHandler("wordpress", wordpressImageName, false))
+
+	// check all service images
+	base.ComposeCmd("-f", comp.YAMLFullPath(), "images").AssertOutWithFunc(ImageAssertHandler("db", dbImageName, true))
+	base.ComposeCmd("-f", comp.YAMLFullPath(), "images").AssertOutWithFunc(ImageAssertHandler("wordpress", wordpressImageName, true))
+}