CodeCov workflow (DjangoGirls/djangogirls)

The CodeCov workflow from DjangoGirls/djangogirls, explained and optimized by Latchkey.

What it does

This is the CodeCov workflow from the DjangoGirls/djangogirls repository, a real project running GitHub Actions. It is shown here with attribution under its BSD-3-Clause license.

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

The workflow

name: CodeCov
on: [push, pull_request]

jobs:
  run:
    runs-on: ubuntu-latest
    env:
      OS: ubuntu-latest
      PYTHON: '3.10'

    strategy:
      max-parallel: 4
      matrix:
        python-version:
        - '3.10'

    services:
      postgres:
        image: postgres:10.8
        env:
          POSTGRES_USER: postgres
          POSTGRES_PASSWORD: postgres
          POSTGRES_DB: djangogirls
        ports:
          - 5432:5432
        # needed because the postgres container does not provide a healthcheck
        options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5

    steps:
    - uses: actions/checkout@v2
      with:
        fetch-depth: '2'

    - name: Setup Python ${{ matrix.python-version }}
      uses: actions/setup-python@master
      with:
        python-version: ${{ matrix.python-version }}
    - name: Generate Report
      run: |
        pip install -r requirements.txt
        coverage run -m pytest
        coverage xml
      env:
        POSTGRES_DB: djangogirls
        POSTGRES_HOST: localhost
        POSTGRES_PASSWORD: postgres
        POSTGRES_USER: postgres
    - name: Upload Coverage to Codecov
      uses: codecov/codecov-action@v2

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: CodeCov
on: [push, pull_request]
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  run:
    timeout-minutes: 30
    runs-on: latchkey-small
    env:
      OS: ubuntu-latest
      PYTHON: '3.10'
 
    strategy:
      max-parallel: 4
      matrix:
        python-version:
        - '3.10'
 
    services:
      postgres:
        image: postgres:10.8
        env:
          POSTGRES_USER: postgres
          POSTGRES_PASSWORD: postgres
          POSTGRES_DB: djangogirls
        ports:
          - 5432:5432
        # needed because the postgres container does not provide a healthcheck
        options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
 
    steps:
    - uses: actions/checkout@v2
      with:
        fetch-depth: '2'
 
    - name: Setup Python ${{ matrix.python-version }}
      uses: actions/setup-python@master
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
    - name: Generate Report
      run: |
        pip install -r requirements.txt
        coverage run -m pytest
        coverage xml
      env:
        POSTGRES_DB: djangogirls
        POSTGRES_HOST: localhost
        POSTGRES_PASSWORD: postgres
        POSTGRES_USER: postgres
    - name: Upload Coverage to Codecov
      uses: codecov/codecov-action@v2

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.

1 third-party action is referenced by a movable tag. Pin it to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

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 per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow