README.md

Python Action

A template to bootstrap the creation of a multi-platform Python GitHub action.

Why is this Javascript?

This is actually a hybrid action that executes Python with a Javascript action wrapper. The reason for this is that only Javascript and Docker container actions are currently supported.

Why not use a container action for Python?

• Currently container actions are not multi-platform. You can only run them on linux virtual machines.
• Container actions using image: 'Dockerfile' are slow because they need to build the image from scratch every time the workflow runs.
• Container actions using image: 'docker://my-namespace/my-image:1.0.0' cannot be forked easily because the reference to the public Docker image remains. Being able to fork GitHub actions is important for security conscious users.

Actions using this template

• Create Issue From File

Usage

Develop action

• Modify action.yml to describe the action

• Modify index.js to pass action inputs to the Python script

• Set the version of Python required in index.js

      // Setup Python from the tool cache
      setupPython("3.8.x", "x64");

  Note: The GitHub Actions tool cache only seems to keep the latest builds of major.minor.build tool versions. So it's best to follow the minor version rather than an explicit build. For example, use 3.8.x instead of 3.8.1.

• Add Python dependencies to requirements.txt

Install javascript dependencies

npm install

Package for distribution

This will use ncc to compile the Node.js code and dependencies into a single file. Python dependencies are vendored to the dist/vendor directory.

npm run package

Note: Packaging the action is necessary even when making changes to the Python source code in src. Changes made will be packaged into dist.

Release

1. Commit the dist directory changes to master
2. Tag the commit or make a GitHub release

License

MIT