KEA DHCP Lease to Reservation Promotion GUI

A web-based GUI for promoting KEA DHCP leases to permanent reservations.

Features

• Connect to KEA DHCP server via Control Agent API
• View active DHCPv4 leases
• Promote leases to permanent reservations with a single click
• Import/Export DHCP reservations - Backup and restore reservations easily
• Simple, intuitive web interface

Architecture

• Backend: Python Flask application
• Frontend: HTML/JavaScript with Bootstrap
• KEA Integration: KEA Control Agent REST API
• Deployment: Docker container

Prerequisites

• KEA DHCP server with Control Agent enabled
• KEA Hook Libraries (required):
  • lease_cmds - For viewing leases
  • host_cmds - For creating/managing reservations
• Docker (for containerized deployment)

KEA Configuration Requirements

1. Enable Control Agent

Your KEA server must have the Control Agent running. Add this to your KEA configuration (/etc/kea/kea-ctrl-agent.conf):

{
  "Control-agent": {
    "http-host": "0.0.0.0",
    "http-port": 8000,
    "control-sockets": {
      "dhcp4": {
        "socket-type": "unix",
        "socket-name": "/tmp/kea4-ctrl-socket"
      }
    }
  }
}

2. Enable Required Hook Libraries (CRITICAL)

Both of these libraries are essential for the GUI to work!

Edit your DHCPv4 configuration (/etc/kea/kea-dhcp4.conf) and add both hook libraries:

{
  "Dhcp4": {
    "hooks-libraries": [
      {
        "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_lease_cmds.so",
        "parameters": {}
      },
      {
        "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_host_cmds.so",
        "parameters": {}
      }
    ],
    // ... rest of your configuration
  }
}

Common hook library paths:

• Debian/Ubuntu: /usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_*.so
• CentOS/RHEL: /usr/lib64/kea/hooks/libdhcp_*.so
• FreeBSD: /usr/local/lib/kea/hooks/libdhcp_*.so
• Alpine Linux: /usr/lib/kea/hooks/libdhcp_*.so

After modifying the configuration, restart KEA:

sudo systemctl restart kea-dhcp4-server
sudo systemctl restart kea-ctrl-agent

To verify it's working:

curl -X POST -H "Content-Type: application/json" \
  -d '{"command": "list-commands", "service": ["dhcp4"]}' \
  http://localhost:8000

# You should see these commands:
# - lease4-get-all (from lease_cmds)
# - reservation-add (from host_cmds)

Configuration

Edit config.yaml with your KEA server details:

kea:
  control_agent_url: "http://your-kea-server:8000"
  # Optional authentication
  username: ""
  password: ""

Running Locally

pip install -r requirements.txt
python app.py

Visit:

• Web UI: http://localhost:5000
• API Documentation: http://localhost:5000/apidocs

Running with Docker

Using Pre-built Image (Recommended)

Important: You must mount a configuration file for the container to work properly!

# 1. Create a config.yaml file on your host
cat > config.yaml << 'EOF'
kea:
  control_agent_url: "https://your-kea-server:8000"
  username: "admin"
  password: "your-password"
  default_subnet_id: 1

app:
  host: "0.0.0.0"
  port: 5000
  debug: false
  
logging:
  level: "INFO"
  format: "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
EOF

# 2. Pull the latest image
docker pull awkto/kea-gui-reservations:latest

# 3. Run with your config mounted
docker run -d \
  --name kea-gui \
  -p 5000:5000 \
  -v $(pwd)/config.yaml:/app/config/config.yaml:ro \
  awkto/kea-gui-reservations:latest

# 4. Check logs to verify config was loaded
docker logs kea-gui | head -20
# Should see: "✅ Loaded configuration from /app/config/config.yaml"

⚠️ Common Mistake: Forgetting to mount the config file will cause the container to use default settings (localhost), which will fail!

Using Docker Compose (Easiest)

# 1. Clone the repository or create these files:
# - docker-compose.yml
# - config.yaml

# 2. Edit config.yaml with your KEA server details

# 3. Start the container
docker-compose up -d

# 4. View logs
docker-compose logs -f

Verifying Configuration

After starting the container, verify the config was loaded:

# Check config file exists in container
docker exec kea-gui cat /app/config/config.yaml

# Check via API
curl http://localhost:5000/api/config | jq '.config.kea.control_agent_url'

# Check health
curl http://localhost:5000/api/health

Troubleshooting: If you see errors connecting to localhost when you configured a different server, see DOCKER_CONFIG_TROUBLESHOOTING.md

Building from Source

docker build -t kea-gui .
docker run -d -p 5000:5000 -v $(pwd)/config.yaml:/app/config/config.yaml:ro kea-gui

API Documentation

Interactive API Explorer

This application includes Swagger/OpenAPI documentation with an interactive API explorer:

📚 Access the API documentation at: http://localhost:5000/apidocs

The Swagger UI provides:

• Complete API reference with request/response schemas
• Interactive "Try it out" functionality to test endpoints directly
• Example requests and responses for each endpoint
• Parameter descriptions and validation rules

API Endpoints Summary

• GET /api/health - Health check and KEA connectivity status
• GET /api/leases - Fetch all DHCPv4 leases (optional: filter by subnet)
• GET /api/reservations - List current reservations (optional: filter by subnet)
• POST /api/reservations - Create a new reservation
• POST /api/promote - Promote a lease to permanent reservation
• DELETE /api/reservation/<ip> - Delete a reservation
• GET /api/reservations/export - Export all reservations to JSON file
• POST /api/reservations/import - Import reservations from JSON file
• GET /api/subnets - Get configured DHCP subnets
• POST /api/validate-ip - Validate IP address against subnet
• GET /api/config - Get current configuration (sanitized)
• POST /api/config - Save configuration to file

For detailed documentation including request/response schemas, visit /apidocs when the application is running.

Usage

Managing Leases and Reservations

1. Access the web interface
2. View the list of active DHCP leases
3. Click "Promote" next to any lease
4. Confirm the action
5. The lease is converted to a permanent reservation in KEA

Import/Export Reservations

Export Reservations:

1. Click the "Import/Export" dropdown button
2. Select "Export Reservations"
3. A JSON file will be downloaded to your machine containing all current reservations
4. You can optionally filter by subnet before exporting

Import Reservations:

1. Click the "Import/Export" dropdown button
2. Select "Import Reservations"
3. Choose a JSON file from your computer (see sample_reservations.json for format)
4. Click "Import" to begin the process
5. The system will:
   • Process each reservation one by one
   • Continue importing even if individual reservations fail
   • Display a summary showing:
     • Number of successfully imported reservations
     • Number of failed imports
     • Details of any failures (duplicate IPs, subnet mismatches, etc.)

Import File Format: The import file should be a JSON file with this structure:

{
  "reservations": [
    {
      "ip-address": "192.168.1.100",
      "hw-address": "aa:bb:cc:dd:ee:01",
      "hostname": "device1",
      "subnet-id": 1
    }
  ]
}

Or simply an array of reservations:

[
  {
    "ip-address": "192.168.1.100",
    "hw-address": "aa:bb:cc:dd:ee:01",
    "hostname": "device1",
    "subnet-id": 1
  }
]

See sample_reservations.json in the repository for a complete example.

Note: Import failures can occur due to:

• Duplicate IP addresses (reservation already exists)
• IP addresses outside the subnet range
• Invalid MAC addresses
• Missing required fields

The import process will continue even if individual reservations fail, and you'll receive a detailed report at the end.

Security Considerations

• Use HTTPS in production
• Secure your KEA Control Agent with authentication
• Run container with appropriate user permissions
• Consider network isolation

CI/CD

This project includes GitHub Actions for automated Docker image builds. See CICD_SETUP.md for setup instructions.

Docker images are automatically published to Docker Hub on tagged releases.

License

MIT