This is a Github Action to allow you to run Container Diff in a Github Actions workflow. The intended use case is to build a Docker container from the repository, push it to Docker Hub, and then use container-diff to extract metadata for it that you can use in other workflows (such as deploying to Github pages). You can also run container diff to extract metadata for a container you've just built locally in the action.

The action accepts the following parameters:

See below for a simple example. Another interesting use case would be to generate metadata and upload to an OCI registry using OCI Registry As Storage.

Given an existing container on Docker Hub, we can run container diff without doing any kind of build.

name: Run container-diff

on: 
  pull_request: []

jobs:
  container-diff:
    name: Run container-diff
    steps:
      - name: Checkout
        uses: actions/checkout@v4
      - name: Run container-diff
        uses: GoogleContainerTools/container-diff/actions@master
        with:
          # Note this command is the default and does not need to be included
          command: analyze          
          args: vanessa/salad --type=file --output=./data.json --json
      - name: View output
        run: cat ./data.json

In the above, we run container-diff to output apt and pip packages, history, and the filesystem for the container "vanessa/salad" that already exists on Docker Hub. We save the result to a data.json output file. The final step in the workflow (list) is a courtesy to show that the data.json file is generated.