lessoncraft

LessonCraft

LessonCraft is a web-based e-learning environment built to provide a simple and straightforward way to build and experience e-learning lessons that utilize a customized markdown syntax alongside interactive, live environments dynamically created using Docker containers and clusters.

Overview

LessonCraft enables educators to:

1. Create Interactive Lessons: Build lessons using a specialized Markdown format with code blocks for commands, expected outputs, and questions.
2. Provide Live Environments: Give learners access to real Docker environments where they can execute commands and see results in real-time.
3. Validate Learning: Automatically validate learner progress by comparing command outputs with expected results.

A live deployment of LessonCraft is coming soon. Stay tuned for updates!

Getting Started

Requirements

• Docker 18.06.0+
• Go 1.24.0+ (stable release)
• MongoDB (for lesson storage)

Development Setup

1. Clone the repository:

   git clone https://github.com/ringo380/lessoncraft
   cd lessoncraft
   

2. Verify Docker is installed and running:

   docker run hello-world
   

3. Load the IPVS kernel module (required for Docker swarm functionality):

   sudo modprobe xt_ipvs
   

4. Initialize Docker swarm mode:

   docker swarm init
   

5. Pull the required Docker image:

   docker pull franela/dind
   

6. Configure environment variables (optional):

   # Copy the sample environment file
   cp .env.sample .env
   
   # Edit the .env file to customize your configuration
   nano .env
   

7. Prepare Go modules:

   go mod tidy
   go mod vendor  # Optional: pre-fetch dependencies
   

8. Start LessonCraft:

   docker-compose up
   

9. Access the application: Navigate to http://localhost and click "Start" to begin a new LessonCraft session, followed by "ADD NEW INSTANCE" to launch a new terminal instance.

Configuration

LessonCraft can be configured using environment variables. A sample configuration file (.env.sample) is provided as a starting point.

Environment Variables

Host Configuration

• HOST_PORT: The port to expose on the host (default: 80)

Container Names

• HAPROXY_CONTAINER_NAME: Name for the HAProxy container (default: haproxy)
• LESSONCRAFT_CONTAINER_NAME: Name for the main application container (default: lessoncraft)
• L2_CONTAINER_NAME: Name for the L2 networking container (default: l2)
• MONGODB_CONTAINER_NAME: Name for the MongoDB container (default: mongodb)

Service Configuration

• MONGODB_URI: MongoDB connection string (default: mongodb://mongodb:27017)
• MONGODB_DATABASE: MongoDB database name (default: lessoncraft)

Application Configuration

• LESSONCRAFT_UNSAFE: Enable unsafe mode (default: false)
• PLAYGROUND_DOMAIN: Domain for the playground (default: localhost)
• DEFAULT_DIND_IMAGE: Default Docker-in-Docker image (default: franela/dind)
• AVAILABLE_DIND_IMAGES: Available Docker-in-Docker images (default: franela/dind)
• ALLOW_WINDOWS_INSTANCES: Allow Windows instances (default: false)
• DEFAULT_SESSION_DURATION: Default session duration (default: 4h)
• MAX_LOAD_AVG: Maximum allowed load average (default: 100)

Security Configuration

• APPARMOR_PROFILE: AppArmor profile for containers (default: docker-dind)
• DOCKER_CONTENT_TRUST: Enable Docker content trust (default: 1)
• COOKIE_HASH_KEY: Hash key for secure cookies
• COOKIE_BLOCK_KEY: Block key for secure cookies
• ADMIN_TOKEN: Token for admin endpoints

Ports

• SSH_PORT: Port for SSH access (default: 8022)
• DNS_PORT: Port for DNS service (default: 8053)
• TLS_PORT: Port for TLS connections (default: 443)

Persistent Volumes

LessonCraft uses several Docker volumes for persistent data:

• sessions: Stores session data for the main application
• networks: Stores network configuration for the L2 container
• data: Stores application data for the main application
• mongodb_data: Stores MongoDB database files

You can customize the volume names using environment variables:

• SESSIONS_VOLUME: Name for the sessions volume (default: sessions)
• NETWORKS_VOLUME: Name for the networks volume (default: networks)
• DATA_VOLUME: Name for the data volume (default: data)
• MONGODB_DATA_VOLUME: Name for the MongoDB data volume (default: mongodb_data)

Resource Limits

Resource limits are configured directly in the docker-compose.yml file:

• HAProxy: 256MB memory, 0.5 CPU cores
• LessonCraft: 512MB memory, 1.0 CPU cores
• L2: 512MB memory, 1.0 CPU cores
• MongoDB: 512MB memory, 0.5 CPU cores

Running Tests

Run all tests:

go test ./...

Run tests with verbose output:

go test -v ./...

Run specific tests:

go test -v ./lesson
go test -v ./api
go test -v ./api/store

Port Forwarding

In order for port forwarding to work correctly in development you need to make *.localhost resolve to 127.0.0.1. That way when you try to access pwd10-0-0-1-8080.host1.localhost, you're forwarded correctly to your local LessonCraft server.

You can achieve this by setting up a dnsmasq server (you can run it in a docker container also) and adding the following configuration:

address=/localhost/127.0.0.1

Don't forget to change your computer's default DNS to use the dnsmasq server to resolve.

API Documentation

LessonCraft provides a RESTful API for managing lessons:

Lesson Management

Lesson Interaction

For detailed API documentation, including request and response formats, see docs/lesson_format.md.

Lesson Format

LessonCraft uses a specialized Markdown format for creating interactive lessons. Lessons consist of:

1. Title: A level 1 heading (# Title)
2. Description: Text following the title
3. Steps: A series of steps, each containing content, commands, expected outputs, and/or questions

Code Blocks

LessonCraft uses specialized code blocks:

• Docker Blocks (````docker`): Define commands to execute
• Expect Blocks (````expect`): Define expected command output
• Question Blocks (````question`): Define questions for the user

For a complete guide to the lesson format, see docs/lesson_format.md.

Troubleshooting

Common Issues

1. Port conflicts: Ensure ports 80 and 443 are available

   # Check if ports are in use
   sudo lsof -i :80
   sudo lsof -i :443
   

2. Docker permissions: Make sure your user has permissions to access the Docker socket

   # Add your user to the docker group
   sudo usermod -aG docker $USER
   # Then log out and back in
   

3. DNS resolution: For port forwarding, ensure *.localhost resolves to 127.0.0.1

   # Test DNS resolution
   ping test.localhost
   # Should resolve to 127.0.0.1
   

4. MongoDB connection: Ensure MongoDB is running and accessible

   # Test MongoDB connection
   mongo --eval "db.version()"
   

FAQ

Why is LessonCraft running on ports 80 and 443? Can I change that?

No, it needs to run on those ports for DNS resolution to work. Ideas or suggestions about how to improve this are welcome.

How can I use Copy/Paste shortcuts in the terminal?

• Copy: Ctrl + Insert
• Paste: Shift + Insert

How do I create my own lessons?

See the docs/lesson_format.md guide and check out the example lessons in the examples/lessons directory.