client: Client.ImageImport: close reader on context cancellation

Use a cancelReadCloser to automatically close the reader when the context
is cancelled. Consumers are still recommended to manually close the reader,
but the cancelReadCloser makes the Close idempotent.

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

client/image_import.go

@@ -13,8 +13,10 @@ type ImageImportResult interface {
 	io.ReadCloser
 }
 
-// ImageImport creates a new image based on the source options.
+// ImageImport creates a new image based on the source options. It returns the
-// It returns the JSON content in the response body.
+// JSON content in the [ImageImportResult].
+//
+// The underlying [io.ReadCloser] is automatically closed if the context is canceled,
 func (cli *Client) ImageImport(ctx context.Context, source ImageImportSource, ref string, options ImageImportOptions) (ImageImportResult, error) {
 	if ref != "" {
 		// Check if the given image name can be resolved
@@ -48,30 +50,17 @@ func (cli *Client) ImageImport(ctx context.Context, source ImageImportSource, re
 	if err != nil {
 		return nil, err
 	}
-	return &imageImportResult{body: resp.Body}, nil
+	return &imageImportResult{
+		ReadCloser: newCancelReadCloser(ctx, resp.Body),
+	}, nil
 }
 
 // ImageImportResult holds the response body returned by the daemon for image import.
 type imageImportResult struct {
-	// body must be closed to avoid a resource leak
+	io.ReadCloser
-	body io.ReadCloser
 }
 
 var (
 	_ io.ReadCloser     = (*imageImportResult)(nil)
 	_ ImageImportResult = (*imageImportResult)(nil)
 )
-
-func (r *imageImportResult) Read(p []byte) (int, error) {
-	if r == nil || r.body == nil {
-		return 0, io.EOF
-	}
-	return r.body.Read(p)
-}
-
-func (r *imageImportResult) Close() error {
-	if r == nil || r.body == nil {
-		return nil
-	}
-	return r.body.Close()
-}

integration/container/export_test.go

@@ -34,6 +34,7 @@ func TestExportContainerAndImportImage(t *testing.T) {
 		SourceName: "-",
 	}, reference, client.ImageImportOptions{})
 	assert.NilError(t, err)
+	defer func() { _ = importRes.Close() }()
 
 	// If the import is successfully, then the message output should contain
 	// the image ID and match with the output from `docker images`.

integration/plugin/authz/authz_plugin_test.go

@@ -460,17 +460,17 @@ func imageImport(ctx context.Context, apiClient client.APIClient, path string) e
 		return err
 	}
 	defer file.Close()
-	options := client.ImageImportOptions{}
 	ref := ""
 	source := client.ImageImportSource{
 		Source:     file,
 		SourceName: "-",
 	}
-	responseReader, err := apiClient.ImageImport(ctx, source, ref, options)
+	resp, err := apiClient.ImageImport(ctx, source, ref, client.ImageImportOptions{})
 	if err != nil {
 		return err
 	}
-	defer responseReader.Close()
+	_, _ = io.Copy(io.Discard, resp)
+	_ = resp.Close()
 	return nil
 }
 

vendor/github.com/moby/moby/client/image_import.go

@@ -13,8 +13,10 @@ type ImageImportResult interface {
 	io.ReadCloser
 }
 
-// ImageImport creates a new image based on the source options.
+// ImageImport creates a new image based on the source options. It returns the
-// It returns the JSON content in the response body.
+// JSON content in the [ImageImportResult].
+//
+// The underlying [io.ReadCloser] is automatically closed if the context is canceled,
 func (cli *Client) ImageImport(ctx context.Context, source ImageImportSource, ref string, options ImageImportOptions) (ImageImportResult, error) {
 	if ref != "" {
 		// Check if the given image name can be resolved
@@ -48,30 +50,17 @@ func (cli *Client) ImageImport(ctx context.Context, source ImageImportSource, re
 	if err != nil {
 		return nil, err
 	}
-	return &imageImportResult{body: resp.Body}, nil
+	return &imageImportResult{
+		ReadCloser: newCancelReadCloser(ctx, resp.Body),
+	}, nil
 }
 
 // ImageImportResult holds the response body returned by the daemon for image import.
 type imageImportResult struct {
-	// body must be closed to avoid a resource leak
+	io.ReadCloser
-	body io.ReadCloser
 }
 
 var (
 	_ io.ReadCloser     = (*imageImportResult)(nil)
 	_ ImageImportResult = (*imageImportResult)(nil)
 )
-
-func (r *imageImportResult) Read(p []byte) (int, error) {
-	if r == nil || r.body == nil {
-		return 0, io.EOF
-	}
-	return r.body.Read(p)
-}
-
-func (r *imageImportResult) Close() error {
-	if r == nil || r.body == nil {
-		return nil
-	}
-	return r.body.Close()
-}