CI workflow (dbr/tvnamer)

The CI workflow from dbr/tvnamer, explained and optimized by Latchkey.

What it does

This is the CI workflow from the dbr/tvnamer repository, a real project running GitHub Actions. It is shown here with attribution under its Unlicense license.

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

The workflow

name: CI

on:
  - push
  - pull_request

jobs:
  build:

    strategy:
      matrix:
        python-version: ['3.5', '3.6', '3.7', '3.8', '3.9']
        os:
          - ubuntu-latest
          - macOS-latest
          # - windows-latest

    name: Test on ${{ matrix.python-version }} and ${{ matrix.os }}
    runs-on: ${{ matrix.os }}

    steps:
    - uses: actions/checkout@v1
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v2
      with:
        python-version: ${{ matrix.python-version }}
    - name: Install dev deps
      run: |
        pip install codecov
        pip install -r requirements-dev.txt
        python setup.py develop
    - name: Run tests
      run: python -m pytest
    - name: Upload test results
      run: codecov

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: CI
 
on:
  - push
  - pull_request
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  build:
    timeout-minutes: 30
 
    strategy:
      matrix:
        python-version: ['3.5', '3.6', '3.7', '3.8', '3.9']
        os:
          - ubuntu-latest
          - macOS-latest
          # - windows-latest
 
    name: Test on ${{ matrix.python-version }} and ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
 
    steps:
    - uses: actions/checkout@v1
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v2
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
    - name: Install dev deps
      run: |
        pip install codecov
        pip install -r requirements-dev.txt
        python setup.py develop
    - name: Run tests
      run: python -m pytest
    - name: Upload test results
      run: codecov
 

What changed

• Cancel superseded runs when a branch or PR gets a newer push.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 (10 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