GoogleContainerTools/skaffold · error

%v is not a valid GCS path

Error message

%v is not a valid GCS path

What it means

DownloadFromGCS requires every entry in the manifests slice to be a GCS URI; entries that are empty or lack the 'gs://' prefix (gcsPrefix) are rejected with '%v is not a valid GCS path'. This guards the GCS client from being handed a local path or garbage.

Source

Thrown at pkg/skaffold/kubernetes/manifest/gcs.go:49

type GCSClient interface {
	// Downloads the content that match the given src uri and subfolders.
	DownloadRecursive(ctx context.Context, src, dst string) error
}

var GetGCSClient = func() GCSClient {
	return &client.Native{}
}

// DownloadFromGCS downloads all provided manifests from a remote GCS bucket,
// and returns a relative path pointing to the GCS temp dir.
func DownloadFromGCS(manifests []string) (string, error) {
	dir := filepath.Join(ManifestTmpDir, ManifestsFromGCS)
	if err := os.MkdirAll(dir, os.ModePerm); err != nil {
		return "", fmt.Errorf("failed to create the tmp directory: %w", err)
	}
	for _, manifest := range manifests {
		if manifest == "" || !strings.HasPrefix(manifest, gcsPrefix) {
			return "", fmt.Errorf("%v is not a valid GCS path", manifest)
		}
		gcs := GetGCSClient()
		if err := gcs.DownloadRecursive(context.Background(), manifest, dir); err != nil {
			return "", fmt.Errorf("failed to download manifests fom GCS: %w", err)
		}
	}
	return ManifestTmpDir, nil
}

View on GitHub (pinned to a1189de023)

Solutions

1. Ensure each manifest entry is a full 'gs://bucket/path' URI, including the gs:// scheme
2. Remove or filter out empty strings from the manifests list before calling
3. Fix typos like 'gcs://' or 's3://' — only 'gs://' is accepted
4. If local manifests must be supported, handle them separately instead of passing them to DownloadFromGCS

Example fix

// before
remoteManifests := []string{"my-bucket/manifests"}       // missing scheme
remoteManifests := []string{""}                          // empty entry
// after
remoteManifests := []string{"gs://my-bucket/manifests"}

import "strings"
func allGCSURIs(manifests []string) bool {
  for _, m := range manifests {
    if m == "" || !strings.HasPrefix(m, "gs://") { return false }
  }
  return true
}
// guard: if !allGCSURIs(remoteManifests) { fix config before DownloadFromGCS }

isGCSPath := func(s string) bool {
  return strings.HasPrefix(s, "gs://") && len(s) > len("gs://")
}

if path, err := manifest.DownloadFromGCS(manifests); err != nil {
  if strings.Contains(err.Error(), "not a valid GCS path") {
    // log offending entries, filter them out, retry
    return fmt.Errorf("skipping non-GCS manifest entries: %w", err)
  }
  return err
}

When it happens

Trigger: Calling manifest.DownloadFromGCS with a manifests slice containing an empty string, a local file path (e.g. 'manifests/', '/abs/path.yaml'), an https URL, or a 'gcs://' typo instead of 'gs://...'.

Common situations: Misconfigured remote manifests in skaffold config (missing gs:// prefix), env-substitution producing empty strings, or mixing local and remote manifests in a list intended to be all-GCS.

Related errors

• cannot parse URI %q: %w
• URI scheme is %q, must be 'gs'
• %s is a directory
• cannot add an empty image value
• unable to lookup minikube executable. Please add it to PATH

AI-assisted analysis of GoogleContainerTools/skaffold@a1189de023 (2026-09-05). Data as JSON: /api/errors/8971a089926579f1. Report an issue: GitHub.