CI workflow (epfl-lts2/pyunlocbox)
The CI workflow from epfl-lts2/pyunlocbox, explained and optimized by Latchkey.
F
CI health: F - at risk
Point runs-on at Latchkey and get caching, run de-duplication, job timeouts, SHA-pinned actions, self-healing for flaky steps, and up to 58% lower cost, applied automatically.
What it does
This is the CI workflow from the epfl-lts2/pyunlocbox 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
workflow (.yml)
name: CI
on:
push:
branches: [ main, master ]
pull_request:
branches: [ main, master ]
jobs:
pre-commit:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: actions/setup-python@v5
with:
python-version: "3.11"
- uses: pre-commit/action@v3.0.1
test:
runs-on: ubuntu-latest
strategy:
fail-fast: true
matrix:
python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
steps:
- uses: actions/checkout@v4
- name: Install uv
uses: astral-sh/setup-uv@v4
with:
version: "latest"
- name: Set up Python ${{ matrix.python-version }}
run: uv python install ${{ matrix.python-version }}
- name: Install dependencies
run: |
uv sync --dev
# Install additional system dependencies for documentation
sudo apt-get update
sudo apt-get install -y graphviz
# - name: Lint with flake8
# run: |
# # Replicate: flake8 --doctests --exclude=doc, also exclude .venv
# uv run flake8 --doctests --exclude=doc,.venv
- name: Test with pytest
run: |
# Set matplotlib backend for headless testing
export MPLBACKEND=agg
# Run tests with pytest and coverage
uv run pytest --cov=pyunlocbox --cov-report=term-missing --cov-report=html --cov-report=xml -v
- name: Upload coverage to Coveralls
if: matrix.python-version == '3.11' # Only upload once
uses: coverallsapp/github-action@v2
with:
github-token: ${{ secrets.GITHUB_TOKEN }}
file: coverage.xml
continue-on-error: true
- name: Build documentation
if: matrix.python-version == '3.11' # Only build docs once
run: |
# Replicate: sphinx-build commands from Makefile
uv run sphinx-build -b html -d doc/_build/doctrees doc doc/_build/html
uv run sphinx-build -b linkcheck -d doc/_build/doctrees doc doc/_build/linkcheck
- name: Upload documentation artifacts
if: matrix.python-version == '3.11'
uses: actions/upload-artifact@v4
with:
name: documentation
path: doc/_build/html/
# Separate job for building and checking distribution
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- name: Install uv
uses: astral-sh/setup-uv@v4
- name: Set up Python
run: uv python install 3.11
- name: Install dependencies
run: uv sync --dev
- name: Build package
run: |
uv build
ls -lh dist/*
- name: Check package
run: |
uv run twine check dist/*
- name: Upload build artifacts
uses: actions/upload-artifact@v4
with:
name: dist
path: dist/
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, master ] pull_request: branches: [ main, master ] concurrency: group: ${{ github.workflow }}-${{ github.ref }} cancel-in-progress: true jobs: pre-commit: timeout-minutes: 30 runs-on: latchkey-small steps: - uses: actions/checkout@v4 - uses: actions/setup-python@v5 with: cache: 'pip' python-version: "3.11" - uses: pre-commit/action@v3.0.1 test: timeout-minutes: 30 runs-on: latchkey-small strategy: fail-fast: true matrix: python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"] steps: - uses: actions/checkout@v4 - name: Install uv uses: astral-sh/setup-uv@v4 with: version: "latest" - name: Set up Python ${{ matrix.python-version }} run: uv python install ${{ matrix.python-version }} - name: Install dependencies run: | uv sync --dev # Install additional system dependencies for documentation sudo apt-get update sudo apt-get install -y graphviz # - name: Lint with flake8 # run: | # # Replicate: flake8 --doctests --exclude=doc, also exclude .venv # uv run flake8 --doctests --exclude=doc,.venv - name: Test with pytest run: | # Set matplotlib backend for headless testing export MPLBACKEND=agg # Run tests with pytest and coverage uv run pytest --cov=pyunlocbox --cov-report=term-missing --cov-report=html --cov-report=xml -v - name: Upload coverage to Coveralls if: matrix.python-version == '3.11' # Only upload once uses: coverallsapp/github-action@v2 with: github-token: ${{ secrets.GITHUB_TOKEN }} file: coverage.xml continue-on-error: true - name: Build documentation if: matrix.python-version == '3.11' # Only build docs once run: | # Replicate: sphinx-build commands from Makefile uv run sphinx-build -b html -d doc/_build/doctrees doc doc/_build/html uv run sphinx-build -b linkcheck -d doc/_build/doctrees doc doc/_build/linkcheck - name: Upload documentation artifacts if: matrix.python-version == '3.11' uses: actions/upload-artifact@v4 with: name: documentation path: doc/_build/html/ # Separate job for building and checking distribution build: timeout-minutes: 30 runs-on: latchkey-small steps: - uses: actions/checkout@v4 - name: Install uv uses: astral-sh/setup-uv@v4 - name: Set up Python run: uv python install 3.11 - name: Install dependencies run: uv sync --dev - name: Build package run: | uv build ls -lh dist/* - name: Check package run: | uv run twine check dist/* - name: Upload build artifacts uses: actions/upload-artifact@v4 with: name: dist path: dist/
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 useslatchkey-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.
3 third-party actions are referenced by a movable tag. Pin them 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 3 jobs (8 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.