GitHub Actions Docker Build Demo

This is a simple demo project showing how to create a GitHub Actions workflow that builds a Docker image and can be triggered manually via the GitHub CLI.

Project Structure

.
├── app.py                          # Simple Python Hello World app
├── Dockerfile                      # Docker configuration
├── .github/workflows/docker-build.yml  # GitHub Actions workflow
└── README.md                       # This file

Prerequisites

1. GitHub CLI - Install from cli.github.com
2. Git - For cloning and pushing to GitHub
3. GitHub Account - To create the repository

Setup Instructions

1. Create GitHub Repository

# Create a new repository on GitHub
gh repo create github-actions-docker-demo --public

# Clone the repository
git clone https://github.com/YOUR_USERNAME/github-actions-docker-demo.git
cd github-actions-docker-demo

2. Add Project Files

Copy all the files from this demo project to your repository:

# Add all files
git add .
git commit -m "Initial commit: Add GitHub Actions Docker workflow demo"
git push origin main

3. Trigger the Workflow

You can trigger the workflow manually using the GitHub CLI:

# Basic workflow run
gh workflow run docker-build.yml

# With custom tag
gh workflow run docker-build.yml -f tag=v1.0.0

# Check workflow status
gh run list --workflow=docker-build.yml

4. View Logs and Output

To view the workflow logs:

# List recent runs
gh run list --workflow=docker-build.yml

# View logs for the most recent run
gh run view --log

# View logs for a specific run ID
gh run view RUN_ID --log

You can also view the logs in the GitHub web interface:

1. Go to your repository on GitHub
2. Click on the "Actions" tab
3. Click on the "Docker Build Workflow" workflow
4. Click on the specific run to see detailed logs

Workflow Features

• Manual Trigger: Uses workflow_dispatch to allow manual triggering
• Docker Build: Builds a Docker image from the Dockerfile
• Container Testing: Runs the container to verify it works
• Build Logs: Shows detailed build output in GitHub Actions interface
• Custom Tags: Allows specifying custom Docker image tags

Sample Output

When you run the workflow, you'll see output like:

🐳 Building Docker image...
✅ Docker image built successfully!
📋 Available Docker images:
🧪 Testing Docker container...
🐳 Hello from Docker!
Current time: 2024-01-15 10:30:45.123456
Python version: 3.11.x
This is a simple demo app for GitHub Actions Docker workflow
Application started successfully!
✅ Container test completed!
📊 Build Summary:
- Image: demo-app:latest
- Build completed at: Mon Jan 15 10:30:45 UTC 2024
- Workflow triggered by: your-username

Customization

• Change the app: Edit app.py to modify the application
• Modify Docker setup: Update Dockerfile for different base images or configurations
• Extend workflow: Add steps to the .github/workflows/docker-build.yml file
• Add triggers: Include other triggers like push or pull_request in the workflow

Troubleshooting

If the workflow fails:

1. Check the logs using gh run view --log
2. Verify all files are properly committed to the repository
3. Ensure the workflow file is in the correct location: .github/workflows/docker-build.yml
4. Make sure Docker syntax is correct in the Dockerfile