Don't try to pull images if there are no images to pull

cmd/dt/pull.go

@@ -2,30 +2,26 @@ package main
 
 import (
 	"context"
-	"errors"
 	"fmt"
 
 	"github.com/spf13/cobra"
 	"github.com/vmware-labs/distribution-tooling-for-helm/internal/log"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/chartutils"
-	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/imagelock"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/utils"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/wrapping"
 )
 
 var pullCmd = newPullCommand()
 
 func pullChartImages(chart wrapping.Lockable, imagesDir string, opts ...chartutils.Option) error {
-	lockFile := chart.LockFilePath()
-
-	lock, err := imagelock.FromYAMLFile(lockFile)
+	lock, err := chart.GetImagesLock()
 	if err != nil {
-		return fmt.Errorf("failed to read Images.lock file")
+		return fmt.Errorf("failed to read Images.lock file: %v", err)
 	}
 	if err := chartutils.PullImages(lock, imagesDir,
 		opts...,
 	); err != nil {
-		return fmt.Errorf("failed to pull images: %w", err)
+		return fmt.Errorf("failed to pull images: %v", err)
 	}
 	return nil
 }
@@ -64,28 +60,30 @@ func newPullCommand() *cobra.Command {
 			if imagesDir == "" {
 				imagesDir = chart.ImagesDir()
 			}
+			lock, err := chart.GetImagesLock()
+			if err != nil {
+				return l.Failf("Failed to load Images.lock: %v", err)
+			}
 
-			var imagesPulled bool
-			if err := l.Section(fmt.Sprintf("Pulling images into %q", chart.ImagesDir()), func(childLog log.SectionLogger) error {
-				if err := pullChartImages(
-					chart,
-					imagesDir,
-					chartutils.WithLog(childLog),
-					chartutils.WithContext(ctx),
-					chartutils.WithProgressBar(childLog.ProgressBar()),
-					chartutils.WithArtifactsDir(chart.ImageArtifactsDir()),
-				); err != nil {
-					if errors.Is(err, chartutils.ErrNoImagesFound) {
-						childLog.Warnf("No images found in Images.lock")
-						return nil
+			if len(lock.Images) == 0 {
+				l.Warnf("No images found in Images.lock")
+			} else {
+				if err := l.Section(fmt.Sprintf("Pulling images into %q", chart.ImagesDir()), func(childLog log.SectionLogger) error {
+					if err := pullChartImages(
+						chart,
+						imagesDir,
+						chartutils.WithLog(childLog),
+						chartutils.WithContext(ctx),
+						chartutils.WithProgressBar(childLog.ProgressBar()),
+						chartutils.WithArtifactsDir(chart.ImageArtifactsDir()),
+					); err != nil {
+						return childLog.Failf("%v", err)
 					}
-					return childLog.Failf("%v", err)
+					childLog.Infof("All images pulled successfully")
+					return nil
+				}); err != nil {
+					return l.Failf("%w", err)
 				}
-				imagesPulled = true
-				childLog.Infof("All images pulled successfully")
-				return nil
-			}); err != nil {
-				return l.Failf("%w", err)
 			}
 
 			if outputFile != "" {
@@ -108,20 +106,8 @@ func newPullCommand() *cobra.Command {
 				successMessage = fmt.Sprintf("All images pulled successfully into %q", chart.ImagesDir())
 			}
 
-			var warningMessage string
-			if outputFile != "" {
-				warningMessage = fmt.Sprintf("No images found in Images.lock. Chart compressed into %q", outputFile)
-			} else {
-				warningMessage = "No images found in Images.lock"
-			}
-
 			l.Printf(terminalSpacer)
-
-			if imagesPulled {
-				l.Successf(successMessage)
-			} else {
-				l.Warnf(warningMessage)
-			}
+			l.Successf(successMessage)
 
 			return nil
 		},

cmd/dt/pull_test.go

@@ -80,15 +80,15 @@ func (suite *CmdSuite) TestPullCommand() {
 		scenarioDir = fmt.Sprintf("../../testdata/scenarios/%s", scenarioName)
 		chartDir := createSampleChart(sb.TempFile())
 		dt("images", "pull", chartDir).AssertSuccessMatch(t, "No images found in Images.lock")
-		verifyChartDir(chartDir)
+		require.NoDirExists(filepath.Join(chartDir, "images"))
 	})
 
 	t.Run("Errors", func(t *testing.T) {
 		t.Run("Fails when Images.lock is not found", func(t *testing.T) {
 			chartDir := createSampleChart(sb.TempFile())
 			require.NoError(os.RemoveAll(filepath.Join(chartDir, "Images.lock")))
 
-			dt("images", "pull", chartDir).AssertErrorMatch(t, `(?s).*failed to read Images\.lock file.*`)
+			dt("images", "pull", chartDir).AssertErrorMatch(t, `Failed to load Images\.lock.*`)
 		})
 	})
 }

cmd/dt/push.go

@@ -3,27 +3,17 @@ package main
 import (
 	"context"
 	"fmt"
-	"os"
 
 	"github.com/spf13/cobra"
 	"github.com/vmware-labs/distribution-tooling-for-helm/internal/log"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/chartutils"
-	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/imagelock"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/wrapping"
 )
 
 var pushCmd = newPushCmd()
 
 func pushChartImages(wrap wrapping.Wrap, imagesDir string, opts ...chartutils.Option) error {
-	lockFile := wrap.LockFilePath()
-
-	fh, err := os.Open(lockFile)
-	if err != nil {
-		return fmt.Errorf("failed to open Images.lock file: %v", err)
-	}
-	defer fh.Close()
-
-	lock, err := imagelock.FromYAML(fh)
+	lock, err := wrap.GetImagesLock()
 	if err != nil {
 		return fmt.Errorf("failed to load Images.lock: %v", err)
 	}

cmd/dt/unwrap.go

@@ -12,7 +12,6 @@ import (
 	"github.com/vmware-labs/distribution-tooling-for-helm/internal/widgets"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/artifacts"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/chartutils"
-	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/imagelock"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/relocator"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/utils"
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/wrapping"
@@ -155,7 +154,7 @@ func pushChartImagesAndVerify(ctx context.Context, wrap wrapping.Wrap, l log.Sec
 }
 
 func showImagesSummary(wrap wrapping.Lockable, l log.SectionLogger) int {
-	lock, err := imagelock.FromYAMLFile(wrap.LockFilePath())
+	lock, err := wrap.GetImagesLock()
 	if err != nil {
 		l.Debugf("failed to load list of images: failed to load lock file: %v", err)
 		return 0

cmd/dt/wrap.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	glog "log"
 	"path/filepath"
@@ -112,27 +111,32 @@ func wrapChart(ctx context.Context, inputPath string, outputFile string, platfor
 		}
 	}
 
-	if err := l.Section(fmt.Sprintf("Pulling images into %q", chart.ImagesDir()), func(childLog log.SectionLogger) error {
-		fetchArtifacts, _ := flags.GetBool("fetch-artifacts")
-		if err := pullChartImages(
-			wrap,
-			wrap.ImagesDir(),
-			chartutils.WithLog(childLog),
-			chartutils.WithContext(ctx),
-			chartutils.WithFetchArtifacts(fetchArtifacts),
-			chartutils.WithArtifactsDir(wrap.ImageArtifactsDir()),
-			chartutils.WithProgressBar(childLog.ProgressBar()),
-		); err != nil {
-			if errors.Is(err, chartutils.ErrNoImagesFound) {
-				childLog.Warnf("No images found in Images.lock")
-				return nil
+	lock, err := chart.GetImagesLock()
+	if err != nil {
+		return l.Failf("Failed to load Images.lock: %v", err)
+	}
+
+	if len(lock.Images) == 0 {
+		l.Warnf("No images found in Images.lock")
+	} else {
+		if err := l.Section(fmt.Sprintf("Pulling images into %q", chart.ImagesDir()), func(childLog log.SectionLogger) error {
+			fetchArtifacts, _ := flags.GetBool("fetch-artifacts")
+			if err := pullChartImages(
+				wrap,
+				wrap.ImagesDir(),
+				chartutils.WithLog(childLog),
+				chartutils.WithContext(ctx),
+				chartutils.WithFetchArtifacts(fetchArtifacts),
+				chartutils.WithArtifactsDir(wrap.ImageArtifactsDir()),
+				chartutils.WithProgressBar(childLog.ProgressBar()),
+			); err != nil {
+				return childLog.Failf("%v", err)
 			}
-			return childLog.Failf("%v", err)
+			childLog.Infof("All images pulled successfully")
+			return nil
+		}); err != nil {
+			return err
 		}
-		childLog.Infof("All images pulled successfully")
-		return nil
-	}); err != nil {
-		return err
 	}
 
 	if shouldCarvelize(flags) {

cmd/dt/wrap_test.go

@@ -123,11 +123,15 @@ func testChartWrap(t *testing.T, sb *tu.Sandbox, inputChart string, expectedLock
 	require.NoError(t, utils.Untar(expectedWrapFile, tmpDir, utils.TarConfig{StripComponents: 1}))
 
 	imagesDir := filepath.Join(tmpDir, "images")
-	require.DirExists(t, imagesDir)
-	for _, imgData := range cfg.Images {
-		for _, digestData := range imgData.Digests {
-			imgDir := filepath.Join(imagesDir, fmt.Sprintf("%s.layout", digestData.Digest.Encoded()))
-			assert.DirExists(t, imgDir)
+	if len(cfg.Images) == 0 {
+		require.NoDirExists(t, imagesDir)
+	} else {
+		require.DirExists(t, imagesDir)
+		for _, imgData := range cfg.Images {
+			for _, digestData := range imgData.Digests {
+				imgDir := filepath.Join(imagesDir, fmt.Sprintf("%s.layout", digestData.Digest.Encoded()))
+				assert.DirExists(t, imgDir)
+			}
 		}
 	}
 	wrappedChartDir := filepath.Join(tmpDir, "chart")

pkg/chartutils/chart.go

@@ -59,6 +59,18 @@ func (c *Chart) LockFilePath() string {
 	return c.AbsFilePath(imagelock.DefaultImagesLockFileName)
 }
 
+// GetImagesLock returns the chart's ImagesLock object
+func (c *Chart) GetImagesLock() (*imagelock.ImagesLock, error) {
+	lockFile := c.LockFilePath()
+
+	lock, err := imagelock.FromYAMLFile(lockFile)
+	if err != nil {
+		return nil, err
+	}
+
+	return lock, nil
+}
+
 // ImageArtifactsDir returns the imags artifacts directory
 func (c *Chart) ImageArtifactsDir() string {
 	return filepath.Join(c.RootDir(), artifacts.HelmArtifactsFolder, "images")

pkg/chartutils/images.go

@@ -2,7 +2,6 @@ package chartutils
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -21,9 +20,6 @@ import (
 	"github.com/vmware-labs/distribution-tooling-for-helm/pkg/utils"
 )
 
-// ErrNoImagesFound is returned when no images are found in the Images.lock file
-var ErrNoImagesFound = errors.New("no images found in Images.lock")
-
 func getNumberOfArtifacts(images imagelock.ImageList) int {
 	n := 0
 	for _, imgDesc := range images {
@@ -54,8 +50,8 @@ func PullImages(lock *imagelock.ImagesLock, imagesDir string, opts ...Option) er
 	}
 	l := cfg.Log
 
-	if getNumberOfArtifacts(lock.Images) == 0 {
-		return ErrNoImagesFound
+	if len(lock.Images) == 0 {
+		return fmt.Errorf("no images found in Images.lock")
 	}
 
 	p, _ := cfg.ProgressBar.WithTotal(getNumberOfArtifacts(lock.Images)).UpdateTitle("Pulling Images").Start()

pkg/chartutils/images_test.go

@@ -67,7 +67,7 @@ func (suite *ChartUtilsTestSuite) TestPullImages() {
 		}
 	})
 
-	t.Run("Warning when no images in Images.lock", func(t *testing.T) {
+	t.Run("Error when no images in Images.lock", func(t *testing.T) {
 		chartDir := sb.TempFile()
 
 		images := []tu.ImageData{}
@@ -82,7 +82,7 @@ func (suite *ChartUtilsTestSuite) TestPullImages() {
 
 		lock, err := imagelock.FromYAMLFile(filepath.Join(chartDir, "Images.lock"))
 		require.NoError(err)
-		require.ErrorIs(PullImages(lock, imagesDir), ErrNoImagesFound)
+		require.Error(PullImages(lock, imagesDir))
 
 		require.DirExists(imagesDir)
 

pkg/imagelock/lock.go

@@ -112,7 +112,7 @@ func FromYAML(r io.Reader) (*ImagesLock, error) {
 func FromYAMLFile(file string) (*ImagesLock, error) {
 	fh, err := os.Open(file)
 	if err != nil {
-		return nil, fmt.Errorf("failed to open Images.lock file: %v", err)
+		return nil, fmt.Errorf("failed to open Images.lock file: %w", err)
 	}
 	defer fh.Close()
 	return FromYAML(fh)

pkg/wrapping/wrap.go

@@ -18,6 +18,7 @@ import (
 type Lockable interface {
 	LockFilePath() string
 	ImagesDir() string
+	GetImagesLock() (*imagelock.ImagesLock, error)
 }
 
 // Wrap defines the interface to implement a Helm chart wrap
@@ -55,6 +56,11 @@ func (w *wrap) ImagesDir() string {
 	return w.AbsFilePath("images")
 }
 
+// GetImagesLock returns the chart's ImagesLock object
+func (w *wrap) GetImagesLock() (*imagelock.ImagesLock, error) {
+	return w.chart.GetImagesLock()
+}
+
 // AbsFilePath returns the absolute path to the Chart relative file name
 func (w *wrap) AbsFilePath(name string) string {
 	return filepath.Join(w.rootDir, name)