CI workflow (evansd/whitenoise)

The CI workflow from evansd/whitenoise, explained and optimized by Latchkey.

CI health: C - fair

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Source: evansd/whitenoise.github/workflows/main.ymlLicense MITView source

What it does

This is the CI workflow from the evansd/whitenoise 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

workflow (.yml)

name: CI

on:
  push:
    branches:
    - main
  pull_request:

concurrency:
  group: ${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

jobs:
  tests:
    name: Python ${{ matrix.python-version }} on ${{ matrix.os }}
    runs-on: ${{ matrix.os }}

    strategy:
      matrix:
        os:
        - ubuntu-24.04
        - windows-2022
        python-version:
        - '3.10'
        - '3.11'
        - '3.12'
        - '3.13'
        - '3.14'

    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      with:
        persist-credentials: false

    - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
      with:
        python-version: ${{ matrix.python-version }}
        allow-prereleases: true

    - name: Install uv
      uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
      with:
        enable-cache: true

    - name: Run tox targets for ${{ matrix.python-version }}
      run: uvx --with tox-uv tox run -f py$(echo ${{ matrix.python-version }} | tr -d .)

    - name: Upload coverage data
      if: matrix.os != 'windows-2022'
      uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
      with:
        name: coverage-data-${{ matrix.python-version }}
        path: '${{ github.workspace }}/.coverage'
        include-hidden-files: true
        if-no-files-found: error

  coverage:
    name: Coverage
    runs-on: ubuntu-24.04
    needs: tests
    if: always()
    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      with:
        persist-credentials: false

    - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
      with:
        python-version: '3.13'

    - name: Install uv
      uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0

    - name: Install dependencies
      run: uv pip install --system coverage[toml]

    - name: Download data
      uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
      with:
        path: .coverage
        pattern: coverage-data-*
        merge-multiple: true

    - name: Combine coverage and fail if it's <100%
      run: |
        python -m coverage combine
        python -m coverage html --skip-covered --skip-empty
        python -m coverage report --fail-under=95
        echo "## Coverage summary" >> $GITHUB_STEP_SUMMARY
        python -m coverage report --format=markdown >> $GITHUB_STEP_SUMMARY

    - name: Upload HTML report
      if: failure()
      uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
      with:
        name: html-report
        path: htmlcov

  release:
    needs: [coverage]
    if: success() && startsWith(github.ref, 'refs/tags/')
    runs-on: ubuntu-24.04
    environment: release

    permissions:
      contents: read
      id-token: write

    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      with:
        persist-credentials: false

    - uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
      with:
        enable-cache: false

    - name: Build
      run: uv build

    - uses: pypa/gh-action-pypi-publish@cef221092ed1bacb1cc03d23a2d87d1d172e277b # v1.14.0

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:
    branches:
    - main
  pull_request:
 
concurrency:
  group: ${{ github.head_ref || github.run_id }}
  cancel-in-progress: true
 
jobs:
  tests:
    timeout-minutes: 30
    name: Python ${{ matrix.python-version }} on ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
 
    strategy:
      matrix:
        os:
        - ubuntu-24.04
        - windows-2022
        python-version:
        - '3.10'
        - '3.11'
        - '3.12'
        - '3.13'
        - '3.14'
 
    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      with:
        persist-credentials: false
 
    - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
        allow-prereleases: true
 
    - name: Install uv
      uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
      with:
        enable-cache: true
 
    - name: Run tox targets for ${{ matrix.python-version }}
      run: uvx --with tox-uv tox run -f py$(echo ${{ matrix.python-version }} | tr -d .)
 
    - name: Upload coverage data
      if: matrix.os != 'windows-2022'
      uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
      with:
        name: coverage-data-${{ matrix.python-version }}
        path: '${{ github.workspace }}/.coverage'
        include-hidden-files: true
        if-no-files-found: error
 
  coverage:
    timeout-minutes: 30
    name: Coverage
    runs-on: latchkey-small
    needs: tests
    if: always()
    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      with:
        persist-credentials: false
 
    - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
      with:
        cache: 'pip'
        python-version: '3.13'
 
    - name: Install uv
      uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
 
    - name: Install dependencies
      run: uv pip install --system coverage[toml]
 
    - name: Download data
      uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
      with:
        path: .coverage
        pattern: coverage-data-*
        merge-multiple: true
 
    - name: Combine coverage and fail if it's <100%
      run: |
        python -m coverage combine
        python -m coverage html --skip-covered --skip-empty
        python -m coverage report --fail-under=95
        echo "## Coverage summary" >> $GITHUB_STEP_SUMMARY
        python -m coverage report --format=markdown >> $GITHUB_STEP_SUMMARY
 
    - name: Upload HTML report
      if: failure()
      uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
      with:
        name: html-report
        path: htmlcov
 
  release:
    timeout-minutes: 30
    needs: [coverage]
    if: success() && startsWith(github.ref, 'refs/tags/')
    runs-on: latchkey-small
    environment: release
 
    permissions:
      contents: read
      id-token: write
 
    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      with:
        persist-credentials: false
 
    - uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
      with:
        enable-cache: false
 
    - name: Build
      run: uv build
 
    - uses: pypa/gh-action-pypi-publish@cef221092ed1bacb1cc03d23a2d87d1d172e277b # v1.14.0

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.
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 3 jobs (12 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

actions/checkout actions/setup-python astral-sh/setup-uv actions/upload-artifact actions/download-artifact