GitHub Actions
Learn how to automate workflows with GitHub Actions, a powerful CI/CD tool integrated directly into your GitHub repository.
GitHub Actions
GitHub Actions is a powerful automation platform that allows you to build, test, and deploy your code directly from your GitHub repository. This feature enables continuous integration and continuous delivery (CI/CD) workflows and can automate virtually any software development process.
Understanding GitHub Actions
- Workflows: Automated procedures defined in YAML files
- Events: Triggers that start workflows (push, PR, schedule, etc.)
- Jobs: Sets of steps that execute on the same runner
- Steps: Individual tasks that run commands or actions
- Actions: Reusable units of code for common tasks
- Runners: Servers that run your workflows
- Native integration with GitHub repositories
- Workflow automation for CI/CD
- Matrix builds across multiple platforms
- Reusable workflows and composite actions
- Secret management for secure automation
- Artifact storage for build outputs
- Rich marketplace of community actions
Creating Your First Workflow
Workflows are defined in YAML files stored in the .github/workflows directory of your repository.
- Create a
.github/workflowsdirectory in your repository - Add a new YAML file (e.g.,
ci.yml) with your workflow definition - Define the events that trigger the workflow
- Configure the jobs and steps to run
- Commit and push your workflow file
Here's a simple example of a workflow that runs tests on every push and pull request:
name: Run Tests
on:
push:
branches: [ main ]
pull_request:
branches: [ main ]
jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Set up Node.js
uses: actions/setup-node@v3
with:
node-version: '16'
- name: Install dependencies
run: npm ci
- name: Run tests
run: npm test
GitHub provides starter workflow templates for common scenarios. Look for the "Actions" tab in your repository and click "New workflow" to browse available templates.
Common GitHub Actions Use Cases
- Run automated tests on every push or PR
- Lint code for style and quality issues
- Check for security vulnerabilities
- Validate build process
- Generate test coverage reports
- Deploy web applications to hosting services
- Publish packages to registries (npm, PyPI, etc.)
- Create and publish Docker images
- Deploy to cloud services (AWS, Azure, GCP)
- Implement multi-environment deployments
- Label and triage issues automatically
- Generate changelogs for releases
- Schedule periodic maintenance tasks
- Send notifications to team communication tools
- Auto-merge dependabot PRs with passing tests
Advanced GitHub Actions Features
Matrix Builds
Run tests across multiple versions or environments:
jobs:
test:
runs-on: ubuntu-latest
strategy:
matrix:
node-version: [14.x, 16.x, 18.x]
steps:
- uses: actions/checkout@v3
- name: Use Node.js ${{ matrix.node-version }}
uses: actions/setup-node@v3
with:
node-version: ${{ matrix.node-version }}
- run: npm ci
- run: npm test
Reusable Workflows
Share common workflow patterns across repositories:
# In .github/workflows/reusable.yml
name: Reusable Workflow
on:
workflow_call:
inputs:
environment:
required: true
type: string
jobs:
deploy:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Deploy to ${{ inputs.environment }}
run: ./deploy.sh ${{ inputs.environment }}
Always use specific versions of actions (e.g., actions/checkout@v3 instead of actions/checkout@main) to ensure workflow stability.