cli/command/container: createContainer(): return container-ID

This function returned the whole response, but we already handled the
warnings included in the response as part of the function. All consumers
of this function only used the container-ID, so let's simplify and return
just that (it's a non-exported func, so we can change the signature again
if we really need it).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/container/create.go

@@ -104,11 +104,11 @@ func runCreate(dockerCli command.Cli, flags *pflag.FlagSet, options *createOptio
 		reportError(dockerCli.Err(), "create", err.Error(), true)
 		return cli.StatusError{StatusCode: 125}
 	}
-	response, err := createContainer(context.Background(), dockerCli, containerCfg, options)
+	id, err := createContainer(context.Background(), dockerCli, containerCfg, options)
 	if err != nil {
 		return err
 	}
-	fmt.Fprintln(dockerCli.Out(), response.ID)
+	_, _ = fmt.Fprintln(dockerCli.Out(), id)
 	return nil
 }
 
@@ -185,7 +185,7 @@ func newCIDFile(path string) (*cidFile, error) {
 }
 
 //nolint:gocyclo
-func createContainer(ctx context.Context, dockerCli command.Cli, containerCfg *containerConfig, opts *createOptions) (*container.CreateResponse, error) {
+func createContainer(ctx context.Context, dockerCli command.Cli, containerCfg *containerConfig, opts *createOptions) (containerID string, err error) {
 	config := containerCfg.Config
 	hostConfig := containerCfg.HostConfig
 	networkingConfig := containerCfg.NetworkingConfig
@@ -200,13 +200,13 @@ func createContainer(ctx context.Context, dockerCli command.Cli, containerCfg *c
 
 	containerIDFile, err := newCIDFile(hostConfig.ContainerIDFile)
 	if err != nil {
-		return nil, err
+		return "", err
 	}
 	defer containerIDFile.Close()
 
 	ref, err := reference.ParseAnyReference(config.Image)
 	if err != nil {
-		return nil, err
+		return "", err
 	}
 	if named, ok := ref.(reference.Named); ok {
 		namedRef = reference.TagNameOnly(named)
@@ -215,7 +215,7 @@ func createContainer(ctx context.Context, dockerCli command.Cli, containerCfg *c
 			var err error
 			trustedRef, err = image.TrustedReference(ctx, dockerCli, taggedRef)
 			if err != nil {
-				return nil, err
+				return "", err
 			}
 			config.Image = reference.FamiliarString(trustedRef)
 		}
@@ -239,14 +239,14 @@ func createContainer(ctx context.Context, dockerCli command.Cli, containerCfg *c
 	if opts.platform != "" && versions.GreaterThanOrEqualTo(dockerCli.Client().ClientVersion(), "1.41") {
 		p, err := platforms.Parse(opts.platform)
 		if err != nil {
-			return nil, errors.Wrap(err, "error parsing specified platform")
+			return "", errors.Wrap(err, "error parsing specified platform")
 		}
 		platform = &p
 	}
 
 	if opts.pull == PullImageAlways {
 		if err := pullAndTagImage(); err != nil {
-			return nil, err
+			return "", err
 		}
 	}
 
@@ -262,24 +262,24 @@ func createContainer(ctx context.Context, dockerCli command.Cli, containerCfg *c
 			}
 
 			if err := pullAndTagImage(); err != nil {
-				return nil, err
+				return "", err
 			}
 
 			var retryErr error
 			response, retryErr = dockerCli.Client().ContainerCreate(ctx, config, hostConfig, networkingConfig, platform, opts.name)
 			if retryErr != nil {
-				return nil, retryErr
+				return "", retryErr
 			}
 		} else {
-			return nil, err
+			return "", err
 		}
 	}
 
 	for _, w := range response.Warnings {
-		fmt.Fprintf(dockerCli.Err(), "WARNING: %s\n", w)
+		_, _ = fmt.Fprintf(dockerCli.Err(), "WARNING: %s\n", w)
 	}
 	err = containerIDFile.Write(response.ID)
-	return &response, err
+	return response.ID, err
 }
 
 func warnOnOomKillDisable(hostConfig container.HostConfig, stderr io.Writer) {

cli/command/container/create_test.go

@@ -93,18 +93,18 @@ func TestCreateContainerImagePullPolicy(t *testing.T) {
 	cases := []struct {
 		PullPolicy      string
 		ExpectedPulls   int
-		ExpectedBody    container.CreateResponse
+		ExpectedID      string
 		ExpectedErrMsg  string
 		ResponseCounter int
 	}{
 		{
 			PullPolicy:    PullImageMissing,
 			ExpectedPulls: 1,
-			ExpectedBody:  container.CreateResponse{ID: containerID},
+			ExpectedID:    containerID,
 		}, {
 			PullPolicy:      PullImageAlways,
 			ExpectedPulls:   1,
-			ExpectedBody:    container.CreateResponse{ID: containerID},
+			ExpectedID:      containerID,
 			ResponseCounter: 1, // This lets us return a container on the first pull
 		}, {
 			PullPolicy:     PullImageNever,
@@ -142,7 +142,7 @@ func TestCreateContainerImagePullPolicy(t *testing.T) {
 				},
 			}
 			fakeCLI := test.NewFakeCli(client)
-			body, err := createContainer(context.Background(), fakeCLI, config, &createOptions{
+			id, err := createContainer(context.Background(), fakeCLI, config, &createOptions{
 				name:      "name",
 				platform:  runtime.GOOS,
 				untrusted: true,
@@ -153,7 +153,7 @@ func TestCreateContainerImagePullPolicy(t *testing.T) {
 				assert.Check(t, is.ErrorContains(err, tc.ExpectedErrMsg))
 			} else {
 				assert.Check(t, err)
-				assert.Check(t, is.DeepEqual(tc.ExpectedBody, *body))
+				assert.Check(t, is.Equal(tc.ExpectedID, id))
 			}
 
 			assert.Check(t, is.Equal(tc.ExpectedPulls, pullCounter))

cli/command/container/run.go

@@ -144,14 +144,14 @@ func runContainer(dockerCli command.Cli, opts *runOptions, copts *containerOptio
 	ctx, cancelFun := context.WithCancel(context.Background())
 	defer cancelFun()
 
-	createResponse, err := createContainer(ctx, dockerCli, containerCfg, &opts.createOptions)
+	containerID, err := createContainer(ctx, dockerCli, containerCfg, &opts.createOptions)
 	if err != nil {
 		reportError(stderr, "run", err.Error(), true)
 		return runStartContainerErr(err)
 	}
 	if opts.sigProxy {
 		sigc := notifyAllSignals()
-		go ForwardAllSignals(ctx, dockerCli, createResponse.ID, sigc)
+		go ForwardAllSignals(ctx, dockerCli, containerID, sigc)
 		defer signal.StopCatch(sigc)
 	}
 
@@ -164,7 +164,7 @@ func runContainer(dockerCli command.Cli, opts *runOptions, copts *containerOptio
 		waitDisplayID = make(chan struct{})
 		go func() {
 			defer close(waitDisplayID)
-			fmt.Fprintln(stdout, createResponse.ID)
+			_, _ = fmt.Fprintln(stdout, containerID)
 		}()
 	}
 	attach := config.AttachStdin || config.AttachStdout || config.AttachStderr
@@ -173,17 +173,17 @@ func runContainer(dockerCli command.Cli, opts *runOptions, copts *containerOptio
 			dockerCli.ConfigFile().DetachKeys = opts.detachKeys
 		}
 
-		closeFn, err := attachContainer(ctx, dockerCli, &errCh, config, createResponse.ID)
+		closeFn, err := attachContainer(ctx, dockerCli, &errCh, config, containerID)
 		if err != nil {
 			return err
 		}
 		defer closeFn()
 	}
 
-	statusChan := waitExitOrRemoved(ctx, dockerCli, createResponse.ID, copts.autoRemove)
+	statusChan := waitExitOrRemoved(ctx, dockerCli, containerID, copts.autoRemove)
 
 	// start the container
-	if err := client.ContainerStart(ctx, createResponse.ID, types.ContainerStartOptions{}); err != nil {
+	if err := client.ContainerStart(ctx, containerID, types.ContainerStartOptions{}); err != nil {
 		// If we have hijackedIOStreamer, we should notify
 		// hijackedIOStreamer we are going to exit and wait
 		// to avoid the terminal are not restored.
@@ -201,8 +201,8 @@ func runContainer(dockerCli command.Cli, opts *runOptions, copts *containerOptio
 	}
 
 	if (config.AttachStdin || config.AttachStdout || config.AttachStderr) && config.Tty && dockerCli.Out().IsTerminal() {
-		if err := MonitorTtySize(ctx, dockerCli, createResponse.ID, false); err != nil {
+		if err := MonitorTtySize(ctx, dockerCli, containerID, false); err != nil {
-			fmt.Fprintln(stderr, "Error monitoring TTY size:", err)
+			_, _ = fmt.Fprintln(stderr, "Error monitoring TTY size:", err)
 		}
 	}