Julia in GitHub actions

Official Julia GitHub actions¶

julia-actions/setup-julia action downloads julia and adds it to PATH.
julia-actions/julia-buildpkg runs build scripts and installs dependencies for the Julia package.
julia-actions/julia-runtest runs unit test for the Julia project.
julia-actions/cache is a shortcut action to cache Julia artifacts, packages, and registries.
julia-actions/julia-docdeploy deploys documentation.
julia-actions/julia-processcoverage generates test coverage data.

Example workflow:

name: CI

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v3
    - uses: julia-actions/setup-julia@v1
    - uses: julia-actions/cache@v1
    - uses: julia-actions/julia-buildpkg@v1
    - uses: julia-actions/julia-runtest@v1
    - uses: julia-actions/julia-docdeploy@v1
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }}
    - uses: julia-actions/julia-processcoverage@v1
    - uses: codecov/codecov-action@v2
      with:
        files: lcov.info

Using the Julia shell¶

Using Julia shell to run Julia scripts is much cleaner than julia -e 'code'.¹

For example, the two steps do the same:

- name: Run Julia command
  shell: julia --color=yes --project=. --threads=auto {0}
  run: |
    println("Hello, Julia!")
    println("This is fine.")

- name: Run Julia command
  run: julia --color=yes --project=. --threads=auto -e '
    println("Hello, Julia!")
    println("This is fine.")'

Using PyCall.jl¶

In GNU/Linux systems like Ubuntu, PyCall.jl may not be able to install python packages for PyCall.jl because it will first try to use the system Python (/usr/bin/python) and pip. It would fail due to lack of superuser privileges.

To solve this, you can set the PYTHON environment variable to where the Python executable is.²

Either using a blank (PYTHON:'') variable will force Julia to install a local miniconda distribution.
Or using the Python executable from the setup-python action.

- uses: actions/setup-python@v4
  id: py
  with:
    python-version: '3.x'
- uses: julia-actions/setup-julia@v1
  with:
    version: 1
- uses: julia-actions/julia-buildpkg@v1
  env:
    # PYTHON: ''      # Use python from Conda.jl
    PYTHON: ${{ steps.py.outputs.python-path }}  # Use python from setup-python