Introducing container-diff, a tool for quickly comparing container images (Google Open Source Blog)

Google has announced that it has released its container-diff tool under the Apache v2 license. "container-diff helps users investigate image changes by computing semantic diffs between images. What this means is that container-diff figures out on a low-level what data changed, and then combines this with an understanding of package manager information to output this information in a format that's actually readable to users. The tool can find differences in system packages, language-level packages, and files in a container image.Users can specify images in several formats - from local Docker daemon (using the prefix `daemon://` on the image path), a remote registry (using the prefix `remote://`), or a file in the .tar in the format exported by "docker save" command. You can also combine these formats to compute the diff between a local version of an image and a remote version."