This GitHub Action helps you to minify your container image, making it smaller and more secure. With this Action, you can reduce the size of your container image by up to 30x (and even more for compiled languages) without compromising its functionality.

This GitHub Action uses slimtoolkit/slim to minimize your container image. slim is an open-source tool that removes unnecessary files and libraries from your image, resulting in a smaller and more secure container.

Slim uses static and dynamic analysis techniques to identify the components of your image that are not needed at runtime. It also removes debug symbols, unused files, and libraries that are not required by your application, reducing the size of your image.

See their README for more information about how Slim works.

To use this GitHub Action, you will need to have the docker/login-action or docker/build-push-action set up in your workflow as well. These actions will allow you to execute Docker commands needed for this action to run successfully.

Create a workflow file in your repository and add these steps to your job:

      # Build the Docker image first
      - uses: docker/build-push-action@v4
        with:
          push: false
          tags: ${{ github.repository }}:latest

      # Slim it!
      - uses: kitabisa/docker-slim-action@v1
        env:
          DSLIM_HTTP_PROBE: false
        with:
          target: ${{ github.repository }}:latest
          tag: "slim"

      # Push to the registry
      - run: docker image push "${{ github.repository }}" --all-tags

In this example, it will minify ${{ github.repository }}:latest as target and will create a slimmed version of the target image with the slim tag from the input (${{ github.repository }}:slim) then push the images to the registry.

The following input actions are supported:

To view the report results generated by the Slim build command, you can access the report property (Object) of the steps outputs context. Here's an example of how to access it: ${{ steps.<id>.outputs.report }}.

      # Slim it!
      - uses: kitabisa/docker-slim-action@v1
        id: slim
        env:
          DSLIM_HTTP_PROBE: false
        with:
          target: ${{ github.repository }}:latest

      # Dump the report
      - run: echo "${REPORT}"
        env:
          REPORT: ${{ steps.slim.outputs.report }}

The associated scripts and documentation in this project are released under the MIT License.

Binary used in this project include third party materials.