GitHub Actions Concepts

GitHub Actions is GitHub's built-in automation system for CI/CD and other repository-driven workflows.

Core Ideas

• A workflow is defined in YAML.
• A workflow contains one or more jobs.
• A job contains steps.
• Steps run shell commands or reusable actions.

Typical Uses

• Run tests on pull requests.
• Build artifacts or container images.
• Deploy after merges to the main branch.

Example Workflow

name: PR workflow
on: pull_request

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: ./test_script.sh

Practical Notes

• Keep workflows small and explicit.
• Use secrets for credentials and tokens.
• Prefer reusable actions when a step is repeated across repositories.