Overview

This hands-on lab introduces the fundamentals of GitHub Actions by implementing a basic workflow that demonstrates repository checkout and command execution. You'll learn how to create a workflow file, understand its structure, and execute various commands.

Prerequisites

• GitHub account


• A GitHub repository where you have write access


• Basic understanding of YAML syntax



• Basic knowledge of command line operations
  
  Learning Objectives
  
  After completing this lab, you will be able to:




• Create a basic GitHub Actions workflow file




• Understand workflow trigger conditions




• Execute single and multi-line commands




• Use the checkout action




• View and interpret workflow results

Lab Structure

your-repository/

├── .github/

│   └── workflows/

│       └── basic-checkout.yml

└── README.md

Implementation Guide

Step 1: Create Workflow Directory

mkdir -p .github/workflows

Step 2: Create Workflow File

Create .github/workflows/basic-checkout.yml with the following content:

name: Basic Checkout Lab



# Trigger on push to main branch

on:

  push:

    branches:

      - main



# Define jobs and their steps

jobs:

  basic-checkout:

    runs-on: ubuntu-latest

    steps:

      # Step 1: Checkout the repository

      - name: Checkout repository

        uses: actions/checkout@v4



      # Step 2: List repository contents

      - name: List files

        run: ls -la



      # Step 3: Display system information

      - name: Show system info

        run: |

          echo "Repository: $GITHUB_REPOSITORY"

          echo "Operating System: $(uname -a)"

          echo "Current Directory: $(pwd)"



      # Step 4: Check software versions

      - name: Check versions

        run: |

          echo "Node version: $(node --version)"

          echo "Python version: $(python --version)"

          echo "Git version: $(git --version)"

Detailed Explanation

Workflow Trigger

on:

push:

branches:

- main

This section configures the workflow to run whenever code is pushed to the main branch.

Job Configuration

jobs:

basic-checkout:

runs-on: ubuntu-latest

Defines a single job named basic-checkout

Specifies Ubuntu as the runner operating system

Steps Breakdown

`Checkout Step

• name: Checkout repository
  uses: actions/checkout@v4
Uses the official checkout action
Clones your repository into the runner
Essential for accessing repository files
File Listing


• name: List files
  run: ls -la
Lists all files and directories
Includes hidden files
Shows file permissions and ownership
System Information
- name: Show system info
  run: |
  echo "Repository: $GITHUB_REPOSITORY"
  echo "Operating System: $(uname -a)"
  echo "Current Directory: $(pwd)"
Uses multi-line commands
Demonstrates environment variable usage
Shows system details
Version Checks


• name: Check versions
  run: |
  echo "Node version: $(node --version)"
  echo "Python version: $(python --version)"
  echo "Git version: $(git --version)"`
  Checks installed software versions
  Uses command substitution
  Demonstrates multi-line commands
  Expected Outputs
  

File Listing Output

total 24

drwxr-xr-x 4 runner docker 4096 Feb 20 10:00 .

drwxr-xr-x 3 runner docker 4096 Feb 20 10:00 ..

drwxr-xr-x 8 runner docker 4096 Feb 20 10:00 .git

drwxr-xr-x 3 runner docker 4096 Feb 20 10:00 .github

-rw-r--r-- 1 runner docker  654 Feb 20 10:00 README.md

System Information Output

Repository: username/repository-name

Operating System: Linux runner-ubuntu-latest 5.15.0-1047-azure

Current Directory: /home/runner/work/repository-name/repository-name

Version Information Output

Node version: v20.11.0

Python version: Python 3.10.12

Git version: git version 2.42.0

Practice Exercises

Add New Commands Modify the workflow to include:

• Current date and time


• Available disk space


• Memory usage
  Custom Environment Variables Add environment variables:

env:

CUSTOM_MESSAGE: "Hello from GitHub Actions!"

Conditional Execution Add a conditional step:

- name: Conditional step

if: github.event_name == 'push'

run: echo "This was triggered by a push event"

Troubleshooting

Common Issues and Solutions

Workflow Not Triggering

• Verify branch name matches trigger condition


• Check workflow file syntax


• Ensure Actions are enabled in repository settings


• Checkout Action Fails

Verify Git configuration

git config --global --list

Check permissions

ls -la .git

Command Execution Errors

Check command availability on runner

Verify syntax for multi-line commands

Ensure proper environment variable usage

Debugging Tips

Enable debug logging by setting secret ACTIONS_RUNNER_DEBUG to true

Check workflow run logs in GitHub Actions tab

Use echo statements to debug variables

Additional Resources: