How to Use GitHub Actions: Simple Guide for Automation

Use GitHub Actions by creating workflow files in the .github/workflows folder of your repository. Define triggers, jobs, and steps in YAML format to automate tasks like testing or deployment on events such as push or pull_request.

Syntax

A GitHub Actions workflow is defined in a YAML file with these main parts:

• name: The workflow's name.
• on: Events that start the workflow (e.g., push, pull_request).
• jobs: One or more jobs to run, each with steps.
• steps: Commands or actions to execute in order.

yaml

name: Example Workflow
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Run a script
        run: echo "Hello from GitHub Actions!"

Example

This example workflow runs on every push to the repository. It checks out the code and prints a greeting message.

yaml

name: Greeting Workflow
on: [push]
jobs:
  greet:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Say Hello
        run: echo "Hello, GitHub Actions!"

Output

Hello, GitHub Actions!

Common Pitfalls

Common mistakes include:

• Placing workflow files outside .github/workflows folder.
• Using incorrect YAML indentation causing syntax errors.
• Not specifying runs-on for jobs, so the runner is undefined.
• Forgetting to use actions/checkout to get repository code before running commands.

yaml

name: Faulty Workflow
on: push
jobs:
  build:
    steps:
      - name: Missing runner
        run: echo "This will fail"

--- Corrected version ---

name: Fixed Workflow
on: push
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Works now
        run: echo "This works"

Quick Reference

Keyword	Description
name	Defines the workflow name
on	Specifies events that trigger the workflow
jobs	Groups tasks to run
runs-on	Specifies the runner environment
steps	List of commands or actions to execute
uses	Calls an existing action from GitHub Marketplace
run	Runs shell commands

Key Takeaways

Create workflow YAML files inside .github/workflows to enable GitHub Actions.

Define triggers with 'on' and specify jobs with 'runs-on' and 'steps'.

Always include 'actions/checkout' step to access your repository code.

Check YAML indentation carefully to avoid syntax errors.

Use GitHub Marketplace actions to simplify common tasks.