Python package workflow (JelteF/PyLaTeX)

The Python package workflow from JelteF/PyLaTeX, explained and optimized by Latchkey.

What it does

This is the Python package workflow from the JelteF/PyLaTeX repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

name: Python package

on:
  push:
    branches:
    - master
  pull_request:
    branches:
    - master

jobs:
  build:

    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        python-version:
          - "3.7"
          - "3.8"
          - "3.9"
          - "3.10"
          - "3.11"
          - "3.12"
    steps:
      - uses: actions/checkout@v3
      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.python-version }}
          # Disable cache so that issues with new dependencies are found more easily
          # cache: 'pip'
          # cache-dependency-path: |
          #   dev_requirements.txt
          #   setup.py
      - name: Install dependencies
        run: |
          sudo apt-get update
          sudo apt-get install texlive-latex-extra texlive-pictures texlive-science texlive-fonts-recommended lmodern ghostscript
          python -m pip install --upgrade pip
          pip install -r dev_requirements.txt --upgrade
          sudo sed '/pattern=".*PDF.*"/d' -i /etc/ImageMagick*/policy.xml
      - name: Run tests
        run: |
          ./testall.sh

The same workflow, on Latchkey

Estimated ~20% faster on cache hits, plus fewer wasted runs and a safer supply chain. Added and changed lines are highlighted.

name: Python package
 
on:
  push:
    branches:
    - master
  pull_request:
    branches:
    - master
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  build:
    timeout-minutes: 30
 
    runs-on: latchkey-small
    strategy:
      fail-fast: false
      matrix:
        python-version:
          - "3.7"
          - "3.8"
          - "3.9"
          - "3.10"
          - "3.11"
          - "3.12"
    steps:
      - uses: actions/checkout@v3
      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v4
        with:
          cache: 'pip'
          python-version: ${{ matrix.python-version }}
          # Disable cache so that issues with new dependencies are found more easily
          # cache: 'pip'
          # cache-dependency-path: |
          #   dev_requirements.txt
          #   setup.py
      - name: Install dependencies
        run: |
          sudo apt-get update
          sudo apt-get install texlive-latex-extra texlive-pictures texlive-science texlive-fonts-recommended lmodern ghostscript
          python -m pip install --upgrade pip
          pip install -r dev_requirements.txt --upgrade
          sudo sed '/pattern=".*PDF.*"/d' -i /etc/ImageMagick*/policy.xml
      - name: Run tests
        run: |
          ./testall.sh
 

What changed

• Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
• Cancel superseded runs when a branch or PR gets a newer push.
• Cache dependency installs on the setup step so they are served from cache.
• Add a job timeout so a hung step cannot burn hours of runner time.

What Latchkey heals here

This workflow has steps that commonly fail on transient issues (network, registries, flaky browsers). On Latchkey managed runners they are detected, retried, and self-healed instead of failing your build:

• Dependency installs

This workflow runs 1 job (6 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow