chore(images): simplifies ListImages service, server, and client to only list Docker images and not directly access containerd

pkg/api/image.go

@@ -16,11 +16,11 @@ type MachineImage struct {
 // MachineImages represents images present on a particular machine.
 type MachineImages struct {
 	Metadata *pb.Metadata
-	// DockerImages is a list of images present in the Docker internal image store.
-	// It may be empty if Docker uses the containerd image store directly (containerd-snapshotter feature).
-	DockerImages []image.Summary
-	// ContainerdImages is a list of images present in the containerd image store.
-	ContainerdImages []image.Summary
+	// Images is a list of images present on the machine.
+	Images []image.Summary
+	// ContainerdStore indicates whether Docker on the machine uses the containerd image store
+	// (containerd-snapshotter feature).
+	ContainerdStore bool
 }
 
 // ImageFilter defines criteria to filter images in ListImages.

pkg/client/image.go

@@ -42,7 +42,8 @@ func (cli *Client) InspectRemoteImage(ctx context.Context, id string) ([]api.Mac
 	return cli.Docker.InspectRemoteImage(ctx, id)
 }
 
-// ListImages returns a list of images in Docker and containerd on specified machines in the cluster.
+// ListImages returns a list of images on specified machines in the cluster. If no machines are specified in the filter,
+// it lists images on all machines.
 func (cli *Client) ListImages(ctx context.Context, filter api.ImageFilter) ([]api.MachineImages, error) {
 	// Broadcast the image list request to the specified machines or all machines if none specified.
 	listCtx, machines, err := api.ProxyMachinesContext(ctx, cli, filter.Machines)
@@ -75,15 +76,9 @@ func (cli *Client) ListImages(ctx context.Context, filter api.ImageFilter) ([]ap
 			}
 		}
 
-		if len(msg.DockerImages) > 0 {
-			if err = json.Unmarshal(msg.DockerImages, &machineImages[i].DockerImages); err != nil {
-				return nil, fmt.Errorf("unmarshal Docker images: %w", err)
-			}
-		}
-
-		if len(msg.ContainerdImages) > 0 {
-			if err = json.Unmarshal(msg.ContainerdImages, &machineImages[i].ContainerdImages); err != nil {
-				return nil, fmt.Errorf("unmarshal containerd images: %w", err)
+		if len(msg.Images) > 0 {
+			if err = json.Unmarshal(msg.Images, &machineImages[i].Images); err != nil {
+				return nil, fmt.Errorf("unmarshal images: %w", err)
 			}
 		}
 	}