client: Client.ContainerLogs: 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/container_logs.go

@@ -30,6 +30,8 @@ type ContainerLogsResult interface {
 // ContainerLogs returns the logs generated by a container in an [io.ReadCloser].
 // It's up to the caller to close the stream.
 //
+// The underlying [io.ReadCloser] is automatically closed if the context is canceled,
+//
 // The stream format on the response uses one of two formats:
 //
 //   - If the container is using a TTY, there is only a single stream (stdout)
@@ -102,30 +104,15 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 		return nil, err
 	}
 	return &containerLogsResult{
-		body: resp.Body,
+		ReadCloser: newCancelReadCloser(ctx, resp.Body),
 	}, nil
 }
 
 type containerLogsResult struct {
-	// body must be closed to avoid a resource leak
+	io.ReadCloser
-	body io.ReadCloser
 }
 
 var (
 	_ io.ReadCloser       = (*containerLogsResult)(nil)
 	_ ContainerLogsResult = (*containerLogsResult)(nil)
 )
-
-func (r *containerLogsResult) Read(p []byte) (int, error) {
-	if r == nil || r.body == nil {
-		return 0, io.EOF
-	}
-	return r.body.Read(p)
-}
-
-func (r *containerLogsResult) Close() error {
-	if r == nil || r.body == nil {
-		return nil
-	}
-	return r.body.Close()
-}

integration/container/nat_test.go

@@ -100,14 +100,14 @@ func TestNetworkLoopbackNat(t *testing.T) {
 
 	poll.WaitOn(t, container.IsStopped(ctx, apiClient, cID))
 
-	body, err := apiClient.ContainerLogs(ctx, cID, client.ContainerLogsOptions{
+	logs, err := apiClient.ContainerLogs(ctx, cID, client.ContainerLogsOptions{
 		ShowStdout: true,
 	})
 	assert.NilError(t, err)
-	defer body.Close()
+	defer logs.Close()
 
 	var b bytes.Buffer
-	_, err = io.Copy(&b, body)
+	_, err = io.Copy(&b, logs)
 	assert.NilError(t, err)
 
 	assert.Check(t, is.Equal(msg, strings.TrimSpace(b.String())))

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

@@ -30,6 +30,8 @@ type ContainerLogsResult interface {
 // ContainerLogs returns the logs generated by a container in an [io.ReadCloser].
 // It's up to the caller to close the stream.
 //
+// The underlying [io.ReadCloser] is automatically closed if the context is canceled,
+//
 // The stream format on the response uses one of two formats:
 //
 //   - If the container is using a TTY, there is only a single stream (stdout)
@@ -102,30 +104,15 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 		return nil, err
 	}
 	return &containerLogsResult{
-		body: resp.Body,
+		ReadCloser: newCancelReadCloser(ctx, resp.Body),
 	}, nil
 }
 
 type containerLogsResult struct {
-	// body must be closed to avoid a resource leak
+	io.ReadCloser
-	body io.ReadCloser
 }
 
 var (
 	_ io.ReadCloser       = (*containerLogsResult)(nil)
 	_ ContainerLogsResult = (*containerLogsResult)(nil)
 )
-
-func (r *containerLogsResult) Read(p []byte) (int, error) {
-	if r == nil || r.body == nil {
-		return 0, io.EOF
-	}
-	return r.body.Read(p)
-}
-
-func (r *containerLogsResult) Close() error {
-	if r == nil || r.body == nil {
-		return nil
-	}
-	return r.body.Close()
-}