Merge pull request #1498 from Zanadar/34394-run-pull-flag

Adds flag modifying pull behavior for running and creating containers

cli/command/container/create.go

@@ -22,10 +22,18 @@ import (
 	"github.com/spf13/pflag"
 )
 
+// Pull constants
+const (
+	PullImageAlways  = "always"
+	PullImageMissing = "missing" // Default (matches previous behavior)
+	PullImageNever   = "never"
+)
+
 type createOptions struct {
 	name      string
 	platform  string
 	untrusted bool
+	pull      string // alway, missing, never
 }
 
 // NewCreateCommand creates a new cobra.Command for `docker create`
@@ -50,6 +58,8 @@ func NewCreateCommand(dockerCli command.Cli) *cobra.Command {
 	flags.SetInterspersed(false)
 
 	flags.StringVar(&opts.name, "name", "", "Assign a name to the container")
+	flags.StringVar(&opts.pull, "pull", PullImageMissing,
+		`Pull image before creating ("`+PullImageAlways+`"|"`+PullImageMissing+`"|"`+PullImageNever+`")`)
 
 	// Add an explicit help that doesn't have a `-h` to prevent the conflict
 	// with hostname
@@ -175,6 +185,7 @@ func newCIDFile(path string) (*cidFile, error) {
 	return &cidFile{path: path, file: f}, nil
 }
 
+// nolint: gocyclo
 func createContainer(ctx context.Context, dockerCli command.Cli, containerConfig *containerConfig, opts *createOptions) (*container.ContainerCreateCreatedBody, error) {
 	config := containerConfig.Config
 	hostConfig := containerConfig.HostConfig
@@ -212,24 +223,32 @@ func createContainer(ctx context.Context, dockerCli command.Cli, containerConfig
 		}
 	}
 
-	//create the container
-	response, err := dockerCli.Client().ContainerCreate(ctx, config, hostConfig, networkingConfig, opts.name)
-
-	//if image not found try to pull it
-	if err != nil {
-		if apiclient.IsErrNotFound(err) && namedRef != nil {
-			fmt.Fprintf(stderr, "Unable to find image '%s' locally\n", reference.FamiliarString(namedRef))
-
-			// we don't want to write to stdout anything apart from container.ID
+	pullAndTagImage := func() error {
 		if err := pullImage(ctx, dockerCli, config.Image, opts.platform, stderr); err != nil {
-				return nil, err
+			return err
 		}
 		if taggedRef, ok := namedRef.(reference.NamedTagged); ok && trustedRef != nil {
-				if err := image.TagTrusted(ctx, dockerCli, trustedRef, taggedRef); err != nil {
+			return image.TagTrusted(ctx, dockerCli, trustedRef, taggedRef)
+		}
+		return nil
+	}
+
+	if opts.pull == PullImageAlways {
+		if err := pullAndTagImage(); err != nil {
 			return nil, err
 		}
 	}
-			// Retry
+
+	response, err := dockerCli.Client().ContainerCreate(ctx, config, hostConfig, networkingConfig, opts.name)
+	if err != nil {
+		// Pull image if it does not exist locally and we have the PullImageMissing option. Default behavior.
+		if apiclient.IsErrNotFound(err) && namedRef != nil && opts.pull == PullImageMissing {
+			// we don't want to write to stdout anything apart from container.ID
+			fmt.Fprintf(stderr, "Unable to find image '%s' locally\n", reference.FamiliarString(namedRef))
+			if err := pullAndTagImage(); err != nil {
+				return nil, err
+			}
+
 			var retryErr error
 			response, retryErr = dockerCli.Client().ContainerCreate(ctx, config, hostConfig, networkingConfig, opts.name)
 			if retryErr != nil {

cli/command/container/create_test.go

@@ -18,7 +18,6 @@ import (
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/network"
 	"github.com/google/go-cmp/cmp"
-	"github.com/pkg/errors"
 	"gotest.tools/assert"
 	is "gotest.tools/assert/cmp"
 	"gotest.tools/fs"
@@ -76,10 +75,40 @@ func TestCIDFileCloseWithWrite(t *testing.T) {
 	assert.NilError(t, err)
 }
 
-func TestCreateContainerPullsImageIfMissing(t *testing.T) {
+func TestCreateContainerImagePullPolicy(t *testing.T) {
 	imageName := "does-not-exist-locally"
-	responseCounter := 0
 	containerID := "abcdef"
+	config := &containerConfig{
+		Config: &container.Config{
+			Image: imageName,
+		},
+		HostConfig: &container.HostConfig{},
+	}
+
+	cases := []struct {
+		PullPolicy      string
+		ExpectedPulls   int
+		ExpectedBody    container.ContainerCreateCreatedBody
+		ExpectedErrMsg  string
+		ResponseCounter int
+	}{
+		{
+			PullPolicy:    PullImageMissing,
+			ExpectedPulls: 1,
+			ExpectedBody:  container.ContainerCreateCreatedBody{ID: containerID},
+		}, {
+			PullPolicy:      PullImageAlways,
+			ExpectedPulls:   1,
+			ExpectedBody:    container.ContainerCreateCreatedBody{ID: containerID},
+			ResponseCounter: 1, // This lets us return a container on the first pull
+		}, {
+			PullPolicy:     PullImageNever,
+			ExpectedPulls:  0,
+			ExpectedErrMsg: "error fake not found",
+		},
+	}
+	for _, c := range cases {
+		pullCounter := 0
 
 		client := &fakeClient{
 			createContainerFunc: func(
@@ -88,17 +117,16 @@ func TestCreateContainerPullsImageIfMissing(t *testing.T) {
 				networkingConfig *network.NetworkingConfig,
 				containerName string,
 			) (container.ContainerCreateCreatedBody, error) {
-			defer func() { responseCounter++ }()
-			switch responseCounter {
+				defer func() { c.ResponseCounter++ }()
+				switch c.ResponseCounter {
 				case 0:
 					return container.ContainerCreateCreatedBody{}, fakeNotFound{}
-			case 1:
-				return container.ContainerCreateCreatedBody{ID: containerID}, nil
 				default:
-				return container.ContainerCreateCreatedBody{}, errors.New("unexpected")
+					return container.ContainerCreateCreatedBody{ID: containerID}, nil
 				}
 			},
 			imageCreateFunc: func(parentReference string, options types.ImageCreateOptions) (io.ReadCloser, error) {
+				defer func() { pullCounter++ }()
 				return ioutil.NopCloser(strings.NewReader("")), nil
 			},
 			infoFunc: func() (types.Info, error) {
@@ -106,24 +134,23 @@ func TestCreateContainerPullsImageIfMissing(t *testing.T) {
 			},
 		}
 		cli := test.NewFakeCli(client)
-	config := &containerConfig{
-		Config: &container.Config{
-			Image: imageName,
-		},
-		HostConfig: &container.HostConfig{},
-	}
 		body, err := createContainer(context.Background(), cli, config, &createOptions{
 			name:      "name",
 			platform:  runtime.GOOS,
 			untrusted: true,
+			pull:      c.PullPolicy,
 		})
-	assert.NilError(t, err)
-	expected := container.ContainerCreateCreatedBody{ID: containerID}
-	assert.Check(t, is.DeepEqual(expected, *body))
-	stderr := cli.ErrBuffer().String()
-	assert.Check(t, is.Contains(stderr, "Unable to find image 'does-not-exist-locally:latest' locally"))
-}
 
+		if c.ExpectedErrMsg != "" {
+			assert.ErrorContains(t, err, c.ExpectedErrMsg)
+		} else {
+			assert.NilError(t, err)
+			assert.Check(t, is.DeepEqual(c.ExpectedBody, *body))
+		}
+
+		assert.Check(t, is.Equal(c.ExpectedPulls, pullCounter))
+	}
+}
 func TestNewCreateCommandWithContentTrustErrors(t *testing.T) {
 	testCases := []struct {
 		name          string

cli/command/container/run.go

@@ -56,6 +56,8 @@ func NewRunCommand(dockerCli command.Cli) *cobra.Command {
 	flags.BoolVar(&opts.sigProxy, "sig-proxy", true, "Proxy received signals to the process")
 	flags.StringVar(&opts.name, "name", "", "Assign a name to the container")
 	flags.StringVar(&opts.detachKeys, "detach-keys", "", "Override the key sequence for detaching a container")
+	flags.StringVar(&opts.createOptions.pull, "pull", PullImageMissing,
+		`Pull image before running ("`+PullImageAlways+`"|"`+PullImageMissing+`"|"`+PullImageNever+`")`)
 
 	// Add an explicit help that doesn't have a `-h` to prevent the conflict
 	// with hostname