GitHub Actions are the CI/CD platform for GitHub repositories, that allow you to trigger workflows in response to events in your repositories.

GitHub Action Components

Workflows

A workflow is a configurable automated process that will run one or more jobs. Workflows are defined in YAML files stored in the .github/workflows directory

Events

Events are specific activities in the repository that can trigger a workflow. These include:

1. pull requests
2. opening an issue
3. commits

Jobs

A Job is a set of steps in a workflow that execute on the same runner. Each step is either a shell script or an action

Actions

An action is a custom application for GitHub Actions platform that performs a complex, repeatable task. The action can be defined in one of

1. a public repository
2. the same repository as the workflow file
3. a published Docker container image

Runners

A runner is a server used to run workflows. Each runner can run a single job at a time

Example Workflow Definition

Workflows are defined in YAML files

name: my-github-workflow

on: # define Events that will trigger the workflow
push:
    branches: [main, develop, release]
schedule:
    # 1am each night
    - cron: "0 1 * * *"

jobs: 
run-first-job:
    name: Run the first job
    runs-on: ubuntu:latest  
    if: github.ref == 'refs/heads/main'
    steps:
    - name: Checkout
        uses: actions/checkout@v3
    - name: Install Node
        uses: actions/setupnode@v3
        with:
        node-version: '14'
    - name: Run the Hello World Action
        uses: ./.github/actions/hello-world-action
        with:
        username: "John Doe"
        secrets:
        password: ${{ secrets.JOHN_PASSWD }}
    - name: Salutation
        run: |
        echo "Thanks for running the workflow"