Docker CI Template

This template will automatically build, release and push docker images for you as soon as a new base image is available.

Simply place a Dockerfile at the root of the repo e.g.:

FROM debian:bookworm-20240211

RUN apt-get update && apt-get install -y \
    fortune \
    cowsay \
    && rm -rf /var/lib/apt/lists/*
RUN echo '/usr/games/fortune | /usr/games/cowsay && echo -e "\n"' >> /etc/bash.bashrc

Is important not to use a tag like latest, stable or any other tag that is not regular updated. For debian there are for example images with a date inside the tag.

The workflows will automatically build and release a new debian images with a cowsay message of the day under the following name: {DOCKER_HUB_USERNAME}/{REPO_NAME}:{BASE_IMAGE_TAG} e.g.: mietzen/debian-cowsay:bookworm-20240211 (The latest image also gets the latest tag)

Cowsay Example: https://github.com/mietzen/debian-cowsay

The workflow will build all platform listed in platforms.json and also push them as a multi-arch image.

Usage

Click on Use this template:

And follow the preparation steps.

Preparation

Github Token App

For the workflow to run you need to create a GitHub-App to generate tokens, follow:

https://github.com/actions/create-github-app-token

If you follow the instructions above you should have your App listed under Settings -> GitHub Apps:

Repository config

You need to activate auto-merge under Settings -> General -> Pull Requests:

and setup the branch protection for main under Settings -> Branch -> Add branch protection rule, for Branch name pattern type in main:

Then apply the following settings:

The status check Check-Build is only available after the docker-image.yml ran at least one time. You can trigger the workflow by simply opening a Pull-Request e.g. to add your Dockerfile.

Secrets

You need to add the following secrets as repository secrets in Actions:

• APP_ID
• APP_PRIVATE_KEY
• DOCKER_HUB_DEPLOY_KEY

and to Dependabot:

• APP_ID
• APP_PRIVATE_KEY

[Optional] Add your DockerHub username and/or the docker image name under variables:

• DOCKER_HUB_USERNAME
• IMAGE_NAME