Fix: Update Docker client to negotiate API version and read OCI spec

main.go

@@ -34,7 +34,6 @@ var verbose = flag.Bool("v", false, "Print all details about the image")
 var filter = flag.Bool("filter", true, "Filters filenames that create noise such as"+
 	" node_modules. Check ignore.go file for more details")
 var extractLayers = flag.Bool("x", false, "Save layers to current directory")
-var specificVersion = flag.String("sV", "", "Set the docker client ID to a specific version -sV=1.47")
 var re *regexp.Regexp
 
 type Manifest struct {
@@ -66,6 +65,7 @@ type dockerHist struct {
 type DockerClient interface {
 	ImageInspectWithRaw(ctx context.Context, imageID string) (image.InspectResponse, []byte, error)
 	ImageSave(ctx context.Context, imageIDs []string, options ...client.ImageSaveOption) (io.ReadCloser, error)
+	ImagePull(ctx context.Context, refStr string, options image.PullOptions) (io.ReadCloser, error)
 	Close() error
 }
 
@@ -172,13 +172,9 @@ func printConfigInfo(config *ImageConfig) {
 func analyze(cli DockerClient, imageID string) {
 	info, _, err := cli.ImageInspectWithRaw(context.Background(), imageID)
 	if err != nil {
-		out, err := cli.ImageSave(context.Background(), []string{imageID})
+		out, err := cli.ImagePull(context.Background(), imageID, image.PullOptions{})
 		if err != nil {
 			color.Red(err.Error())
-			if strings.Contains(err.Error(), "Maximum supported API version is") {
-				version := strings.Split(err.Error(), "Maximum supported API version is ")[1]
-				color.Yellow("Use the -sV flag to change your client version:\n./whaler -sV=%s %s", version, imageID)
-			}
 			return
 		}
 		defer out.Close()
@@ -824,11 +820,7 @@ func main() {
 	}
 
 	// Existing Docker client logic
-	if len(*specificVersion) > 0 {
-		cli, err = client.NewClientWithOpts(client.WithVersion(*specificVersion))
-	} else {
-		cli, err = client.NewClientWithOpts()
-	}
+	cli, err = client.NewClientWithOpts(client.WithAPIVersionNegotiation())
 	if err != nil {
 		color.Red(err.Error())
 		return

main_test.go

@@ -18,7 +18,8 @@ import (
 type MockDockerClient struct {
 	*client.Client
 	imageInspectFunc func(ctx context.Context, imageID string) (image.InspectResponse, []byte, error)
-	imageSaveFunc    func(ctx context.Context, imageIDs []string) (io.ReadCloser, error)
+	imageSaveFunc    func(ctx context.Context, imageIDs []string, options ...client.ImageSaveOption) (io.ReadCloser, error)
+	imagePullFunc    func(ctx context.Context, refStr string, options image.PullOptions) (io.ReadCloser, error)
 }
 
 func (m *MockDockerClient) ImageInspectWithRaw(ctx context.Context, imageID string) (image.InspectResponse, []byte, error) {
@@ -28,9 +29,17 @@ func (m *MockDockerClient) ImageInspectWithRaw(ctx context.Context, imageID stri
 	return image.InspectResponse{}, nil, nil
 }
 
+func (m *MockDockerClient) ImagePull(ctx context.Context, refStr string, options image.PullOptions) (io.ReadCloser, error) {
+	if m.imagePullFunc != nil {
+		return m.imagePullFunc(ctx, refStr, options)
+	}
+	return nil, nil
+}
+
+
 func (m *MockDockerClient) ImageSave(ctx context.Context, imageIDs []string, options ...client.ImageSaveOption) (io.ReadCloser, error) {
 	if m.imageSaveFunc != nil {
-		return m.imageSaveFunc(ctx, imageIDs)
+		return m.imageSaveFunc(ctx, imageIDs, options...)
 	}
 	return nil, nil
 }
@@ -81,11 +90,13 @@ func TestExtractImageLayers(t *testing.T) {
 	// Create a mock Docker client
 	mockClient := &MockDockerClient{
 		Client: &client.Client{},
-		imageSaveFunc: func(ctx context.Context, imageIDs []string) (io.ReadCloser, error) {
+		imageSaveFunc: func(ctx context.Context, imageIDs []string, options ...client.ImageSaveOption) (io.ReadCloser, error) {
 			// Create a tar file in memory with our test data
 			pr, pw := io.Pipe()
 			go func() {
+				defer pw.Close()
 				tw := tar.NewWriter(pw)
+				defer tw.Close()
 
 				// Write a layer file
 				layerContent := "test layer content"
@@ -94,18 +105,25 @@ func TestExtractImageLayers(t *testing.T) {
 					Size: int64(len(layerContent)),
 					Mode: 0600,
 				}
-				tw.WriteHeader(header)
-				tw.Write([]byte(layerContent))
+				if err := tw.WriteHeader(header); err != nil {
+					return
+				}
+				if _, err := tw.Write([]byte(layerContent)); err != nil {
+					return
+				}
 
-				tw.Close()
-				pw.Close()
 			}()
 			return pr, nil
 		},
 	}
 
+	imageStream, err := mockClient.ImageSave(context.Background(), []string{"test-image"})
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	// Test the extractImageLayers function
-	err = extractImageLayers(mockClient, "test-image", []dockerHist{
+	err = extractImageLayers(imageStream, "test-image", []dockerHist{
 		{
 			CreatedBy:  "ADD file:123 /app",
 			LayerID:    "layer1",
@@ -138,7 +156,7 @@ func TestAnalyzeImageFilesystem(t *testing.T) {
 
 	mockClient := &MockDockerClient{
 		Client: &client.Client{},
-		imageSaveFunc: func(ctx context.Context, imageIDs []string) (io.ReadCloser, error) {
+		imageSaveFunc: func(ctx context.Context, imageIDs []string, options ...client.ImageSaveOption) (io.ReadCloser, error) {
 			// Create a tar file in memory with our test data
 			pr, pw := io.Pipe()
 			go func() {
@@ -180,7 +198,7 @@ func TestAnalyzeImageFilesystem(t *testing.T) {
 		},
 	}
 
-	err := analyzeImageFilesystem(mockClient, "test-image")
+	_, err := analyzeImageFilesystem(mockClient, "test-image")
 	if err != nil {
 		t.Errorf("analyzeImageFilesystem failed: %v", err)
 	}