Skill: CI/CD Pipeline

When to Use This Skill

This skill activates when you need to:

•Understand the project's CI/CD setup
•Debug failing CI/CD pipelines
•Fix workflow errors
•Add or modify CI checks
•Understand why checks are failing on your PR

Prerequisites

•Basic understanding of CI/CD concepts
•Access to repository (to view workflow runs)
•Understanding of project's tech stack

Step-by-Step Workflow

Step 1: Identify CI/CD Platform

Check for CI configuration files:

bash

# GitHub Actions
.github/workflows/*.yml

# GitLab CI
.gitlab-ci.yml

# CircleCI
.circleci/config.yml

# Travis CI
.travis.yml

# Jenkins
Jenkinsfile

# Azure Pipelines
azure-pipelines.yml

Step 2: View CI Pipeline Status

GitHub Actions (via CLI):

bash

# Install GitHub CLI if needed
# https://cli.github.com/

# List recent workflow runs
gh run list

# View specific run
gh run view <run-id>

# Watch a running workflow
gh run watch

GitHub Actions (via Web):

•Go to repository on GitHub
•Click "Actions" tab
•Select workflow run
•View job details and logs

Step 3: Understand Common CI Workflows

Typical CI Pipeline Stages

yaml

# .github/workflows/ci.yml example
name: CI
on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup
        # Install dependencies
      - name: Lint
        # Run linter
      - name: Test
        # Run tests
      - name: Build
        # Build project

Common stages:

•Checkout - Clone repository code
•Setup - Install language/dependencies
•Lint - Check code style
•Test - Run test suite
•Build - Compile/build project
•Deploy - Deploy to environment (optional)

Step 4: Debug Failing CI Checks

Step 4a: Identify Which Check Failed

Look at PR checks:

•✅ Green check - Passed
•❌ Red X - Failed
•🟡 Yellow dot - Running
•⚪ Gray circle - Pending

Click on failed check to see:

•Job name
•Failure step
•Error message
•Logs

Step 4b: Common Failure Patterns

Pattern 1: Linting Failures

Error example:

code

Error: Format check failed
black --check . returned non-zero exit code

Fix:

bash

# Run formatter locally
black .
# or
prettier --write .

# Commit and push
git add .
git commit -m "style: fix formatting"
git push

Pattern 2: Test Failures

Error example:

code

FAILED tests/test_user.py::test_login - AssertionError

Fix:

bash

# Run tests locally
pytest tests/test_user.py::test_login -v

# Debug and fix
# Re-run all tests
pytest

# Commit fix
git add .
git commit -m "fix: resolve test failure in login"
git push

Pattern 3: Build Failures

Error example:

code

Error: Module not found: 'missing-package'
npm ERR! code ELIFECYCLE

Fix:

bash

# Add missing dependency
npm install missing-package --save

# Or fix import
# Commit and push
git add package.json package-lock.json
git commit -m "fix: add missing dependency"
git push

Pattern 4: Timeout Errors

Error example:

code

Error: The job exceeded the maximum execution time

Fix:

yaml

# Increase timeout in workflow
jobs:
  test:
    timeout-minutes: 30  # Increase from default 360

Pattern 5: Environment Issues

Error example:

code

Error: Environment variable DATABASE_URL not set

Fix:

yaml

# Add secret/env var in workflow
jobs:
  test:
    env:
      DATABASE_URL: postgresql://localhost/test

Or add in GitHub repository settings:

•Settings → Secrets and variables → Actions
•Add new secret

Step 4c: View Detailed Logs

Download logs:

bash

# GitHub Actions
gh run download <run-id>

# Or via web UI
# Click on failed step → View raw logs → Download

Key things to look for in logs:

•Last successful step before failure
•Exact error message
•Stack trace
•Environment variables
•Dependency versions

Step 5: Fix Common CI Issues

Issue: Tests pass locally but fail in CI

Possible causes:

•Different Python/Node version
•Missing environment variables
•Different OS (Mac vs Linux)
•Cached dependencies
•Timezone differences

Solutions:

yaml

# Match local versions in CI
- uses: actions/setup-python@v4
  with:
    python-version: '3.10'  # Match your local version

# Clear cache
- name: Clear pip cache
  run: pip cache purge

# Set environment variables
env:
  TZ: America/New_York
  DATABASE_URL: ${{ secrets.DATABASE_URL }}

Issue: Linter fails in CI but passes locally

Cause: Different linter version or configuration

Solutions:

bash

# Pin linter version
# requirements.txt
black==23.7.0
ruff==0.0.280

# package.json
"devDependencies": {
  "prettier": "3.0.0",
  "eslint": "8.44.0"
}

# Run same command as CI locally
npm run lint
black --check .

Issue: Build succeeds but deploy fails

Cause: Environment-specific issues

Solutions:

•Check deployment credentials
•Verify target environment is accessible
•Check for deployment-specific env vars
•Review deploy step logs carefully

Step 6: Run CI Checks Locally

GitHub Actions with act:

bash

# Install act
brew install act  # macOS
# or download from github.com/nektos/act

# Run workflow locally
act

# Run specific job
act -j test

# Run with secrets
act --secret-file .env.secrets

Pre-commit hooks (mimics CI):

bash

# Install pre-commit
pip install pre-commit

# Install hooks
pre-commit install

# Run all hooks
pre-commit run --all-files

Step 7: Modify CI Workflow

Add a new check:

yaml

# .github/workflows/ci.yml
jobs:
  security-scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Run security scan
        run: |
          pip install bandit
          bandit -r src/

Add caching:

yaml

- name: Cache dependencies
  uses: actions/cache@v3
  with:
    path: ~/.cache/pip
    key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}

Matrix strategy (test multiple versions):

yaml

jobs:
  test:
    strategy:
      matrix:
        python-version: ['3.8', '3.9', '3.10', '3.11']
    steps:
      - uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.python-version }}

Common CI/CD Patterns

Pattern 1: PR Checks

yaml

name: PR Checks
on: pull_request

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm run lint
  
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm test
  
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm run build

Pattern 2: Main Branch Deploy

yaml

name: Deploy
on:
  push:
    branches: [main]

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Deploy to production
        run: ./deploy.sh
        env:
          DEPLOY_KEY: ${{ secrets.DEPLOY_KEY }}

Pattern 3: Release on Tag

yaml

name: Release
on:
  push:
    tags:
      - 'v*'

jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Build and publish
        run: npm publish

Common Issues and Solutions

Issue: CI is stuck or taking too long

Solutions:

•Check for infinite loops in tests
•Verify no blocking operations
•Increase timeout
•Use caching for dependencies
•Cancel and restart workflow

Issue: Secrets not accessible

Solutions:

•Add secret in repository settings
•Reference correctly: ${{ secrets.SECRET_NAME }}
•Check secret is available for forks (if applicable)
•Verify workflow has correct permissions

Issue: Workflow not triggering

Solutions:

•Check on: triggers match your action
•Verify workflow file syntax is valid
•Check branch name matches filter
•Look for syntax errors in YAML

Success Criteria

•✅ Understand why CI checks failed
•✅ Can reproduce CI failure locally
•✅ Fixed the issue
•✅ CI checks pass on re-run
•✅ Know how to prevent similar failures

Quick Reference

GitHub Actions Commands

bash

# View runs
gh run list
gh run view <run-id>

# Re-run failed jobs
gh run rerun <run-id>

# Download logs
gh run download <run-id>

# Watch live
gh run watch

Common Workflow Triggers

yaml

# On push to any branch
on: push

# On pull request
on: pull_request

# On push to specific branch
on:
  push:
    branches: [main, develop]

# On tag
on:
  push:
    tags: ['v*']

# On schedule (cron)
on:
  schedule:
    - cron: '0 0 * * *'

Related Skills

•run-tests - Run tests locally before pushing
•code-formatting - Fix linting issues
•git-workflow - Push changes to fix CI

ci-pipeline

Skill: CI/CD Pipeline

When to Use This Skill

Prerequisites

Step-by-Step Workflow

Step 1: Identify CI/CD Platform

Step 2: View CI Pipeline Status

Step 3: Understand Common CI Workflows

Typical CI Pipeline Stages

Step 4: Debug Failing CI Checks

Step 4a: Identify Which Check Failed

Step 4b: Common Failure Patterns

Step 4c: View Detailed Logs

Step 5: Fix Common CI Issues

Issue: Tests pass locally but fail in CI

Issue: Linter fails in CI but passes locally

Issue: Build succeeds but deploy fails

Step 6: Run CI Checks Locally

Step 7: Modify CI Workflow

Common CI/CD Patterns

Pattern 1: PR Checks

Pattern 2: Main Branch Deploy

Pattern 3: Release on Tag

Common Issues and Solutions

Issue: CI is stuck or taking too long

Issue: Secrets not accessible

Issue: Workflow not triggering

Success Criteria

Quick Reference

GitHub Actions Commands

Common Workflow Triggers

Related Skills

Documentation References