slimtoolkit/slim · error

bad input data

Error message

bad input data

What it means

layerFromTar validates that the LayerDataInfo.Source path exists and is a regular file before wrapping it as an OCI layer. If the path is missing or is not a plain file, it refuses to build a tar layer and returns "bad input data". This is a fail-fast guard so a nonexistent or directory source never reaches tarball.LayerFromFile.

Source

Thrown at pkg/imagebuilder/internalbuilder/engine.go:261

		//TBD
	}

	id, _ := newImg.ConfigName()
	digest, _ := newImg.Digest()
	result := &imagebuilder.ImageResult{
		Name:      options.Tags[0],
		OtherTags: otherTags,
		ID:        fmt.Sprintf("%s:%s", id.Algorithm, id.Hex),
		Digest:    fmt.Sprintf("%s:%s", digest.Algorithm, digest.Hex),
	}

	return result, nil
}

func layerFromTar(input imagebuilder.LayerDataInfo) (v1.Layer, error) {
	if !fsutil.Exists(input.Source) ||
		!fsutil.IsRegularFile(input.Source) {
		return nil, fmt.Errorf("bad input data")
	}

	return tarball.LayerFromFile(input.Source)
}

func layerFromDir(input imagebuilder.LayerDataInfo) (v1.Layer, error) {
	if !fsutil.Exists(input.Source) ||
		!fsutil.IsDir(input.Source) {
		return nil, fmt.Errorf("bad input data")
	}

	var b bytes.Buffer
	tw := tar.NewWriter(&b)

	layerBasePath := "/"
	if input.Params != nil && input.Params.TargetPath != "" {
		layerBasePath = input.Params.TargetPath
	}

View on GitHub (pinned to 81940d17fa)

Solutions

1. Verify the Source path exists and is a regular file before calling Build (os.Stat / fsutil.Exists + IsRegularFile).
2. Fix the path in the build configuration or the code that produces the tar file.
3. Ensure any earlier pipeline step that generates the tar layer actually succeeded and wrote to Source.

Example fix

// before
builder.Build(ctx, layers: [{Source: "/tmp/out/layer.tar"}]) // file never created
// after
if _, err := os.Stat("/tmp/out/layer.tar"); err != nil { return fmt.Errorf("layer tar missing: %w", err) }
builder.Build(ctx, layers: [{Source: "/tmp/out/layer.tar"}])

info, err := os.Stat(src)
if err != nil || !info.Mode().IsRegular() {
    return fmt.Errorf("layer source %q must be an existing regular file", src)
}

func isValidTarSource(path string) bool {
    info, err := os.Stat(path)
    return err == nil && info.Mode().IsRegular()
}

layer, err := build(ctx, opts)
if err != nil && strings.Contains(err.Error(), "bad input data") {
    // inspect/repair the layer Source path and retry
}

When it happens

Trigger: Calling Build with a layer entry whose LayerDataInfo.Source points to a file that does not exist, has been deleted before build time, or is a directory/symlink/socket rather than a regular file.

Common situations: Passing a wrong path in build config (typo, wrong working directory), expecting a previous build step to have produced a tarball that was never created or was cleaned up, or pointing at a directory when a tar file was required.

Related errors

• podPort cannot be empty
• file path is not absolute
• file is not a binary
• bad parameter
• bad params

AI-assisted analysis of slimtoolkit/slim@81940d17fa (2026-08-31). Data as JSON: /api/errors/8fa019762c0e1b25. Report an issue: GitHub.