[Template] GitHub action: Build and push Docker image on new tag

Template project containing the yml file defining a workflow that builds and pushes the Docker image of the project to GitHub packages and DockerHub everytime a new tag is pushed. The workflow pushes both an image with the tag pushed, as well as an update of the latest version.

The images are pushed to DockerHub, because there seem to have a bug that requires authentification when executing docker pull of public GitHub Docker images (https://github.community/t5/GitHub-Actions/docker-pull-from-public-GitHub-Package-Registry-fail-with-quot/td-p/32782/page/4).

Repository setup

The following secrets need to be defined in the repository. They can be added through Settings > Secrets of the repository.

• APP_NAME: name of the application
• DH_TOKEN: token used for DockerHub authentication
• DH_USERNAME: username used for DockerHub registry authentication
• GH_USERNAME: username used for GitHub registry authentication

Automatic deploy example

This project only builds and pushes the Docker image to registries, but does not deploy the Docker image. Here is an example of how to set an auto-deploy using watchtower:

1. On the server, execute docker pull {dockerhub_username}/{dockerhub_repository}:latest to retrieve the Docker image.
2. Then, execute docker run -itd {image_name} to instantiate and run a Docker container.
3. Watchtower allows to watch for any changes in the running Docker container. So, run the command as indicated on their repository to watch for any changes to the Docker image.