koistya / github-actions-playground

GitHub Actions Playground

GitHub Actions Playground

The following example demonstrates the concept of "reusable workflows" in GitHub Actions.

Directory Structure

• .github/actions — composite actions
• .github/workflows — GitHub Actions workflows
  • deploy.yml — parent workflow
  • deploy-postgres.yml — child workflow
  • deploy-redis.yml — child workflow
  • deploy-vpn.yml — child workflow

.github/workflows/deploy.yml

name: Deploy

on:
  push:
    branches: [main]

jobs:
  postgres:
    name: "PostgreSQL"
    uses: ./.github/workflows/deploy-postgres.yml
  redis:
    name: "Redis"
    uses: ./.github/workflows/deploy-redis.yml
    needs: [postgres]
  vpn:
    name: "OpenVPN"
    uses: ./.github/workflows/deploy-vpn.yml
    needs: [postgres]

• Declares the list of jobs that reference child workflows
• Declares the execution order of the jobs using dependencies (needs)
• Uses short job IDs plus descriptive names
• Fires up on push to the main branch

.github/workflows/deploy-redis.yml

name: Deploy Redis

on: workflow_call

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: 'echo "Step 1"'
      - run: 'echo "Step 2"'
      - run: 'echo "Step 3"'

• Declares a reusable workflow that can be called from other workflows

Using External Workflows

• Create actions repository under your GitHub account (e.g. koistya/actions)
• Create reusable workflows in the .github/workflows folder (e.g. .github/workflows/deploy.yml)
• Create composite actions in the root folder (e.g. create-pod/action.yml)
• Allow access to actions/workflows in the actions repository from external repos

Reference external workflows and composite actions as shown in this example:

name: Deploy

on:
  push:
    branches: [main]

jobs:
  postgres:
    name: "PostgreSQL"
    uses: example/actions/.github/workflows/deploy-postgres.yml@main
  other:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: example/actions/create-pod@main

Where example/actions is the repository containing external workflows such as koistya/actions and @main is the branch name or a tag.

References

• GitHub Actions → Reusable Workflows
• GitHub Actions → Composite Actions