Lint workflow (tryolabs/norfair)

The Lint workflow from tryolabs/norfair, explained and optimized by Latchkey.

What it does

This is the Lint workflow from the tryolabs/norfair 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: Lint

on: [pull_request]

jobs:
  linting:
    runs-on: ubuntu-22.04
    steps:
      - name: Check out repository
        uses: actions/checkout@v3
      - name: Set up python
        id: setup-python
        uses: actions/setup-python@v4
        with:
          python-version: "3.9"
      - name: Install Poetry
        uses: snok/install-poetry@v1
        with:
          virtualenvs-create: true
          virtualenvs-in-project: true
          installer-parallel: true
      - name: Load cached venv
        id: cached-poetry-dependencies
        uses: actions/cache@v4
        with:
          path: .venv
          key: venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('**/poetry.lock') }}
      - name: Install dependencies
        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
        run: poetry install --no-interaction --no-root
      - name: Install library
        run: poetry install --no-interaction
      - name: Test black
        run: |
          source .venv/bin/activate
          black --check --diff .
      # - name: Test isort
      #   run: |
      #     source .venv/bin/activate
      #     isort . --check --diff
      # - name: Test pylint
      #   run: |
      #     source .venv/bin/activate
      #     pylint -E norfair/**/*.py

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: Lint
 
on: [pull_request]
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  linting:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
      - name: Check out repository
        uses: actions/checkout@v3
      - name: Set up python
        id: setup-python
        uses: actions/setup-python@v4
        with:
          cache: 'pip'
          python-version: "3.9"
      - name: Install Poetry
        uses: snok/install-poetry@v1
        with:
          virtualenvs-create: true
          virtualenvs-in-project: true
          installer-parallel: true
      - name: Load cached venv
        id: cached-poetry-dependencies
        uses: actions/cache@v4
        with:
          path: .venv
          key: venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('**/poetry.lock') }}
      - name: Install dependencies
        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
        run: poetry install --no-interaction --no-root
      - name: Install library
        run: poetry install --no-interaction
      - name: Test black
        run: |
          source .venv/bin/activate
          black --check --diff .
      # - name: Test isort
      #   run: |
      #     source .venv/bin/activate
      #     isort . --check --diff
      # - name: Test pylint
      #   run: |
      #     source .venv/bin/activate
      #     pylint -E norfair/**/*.py
 

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