docker-swarm-termina/backend

Backend - Flask API

Python Flask backend for Docker container management.

Features

• RESTful API for container management
• Docker SDK integration
• Session-based authentication
• CORS enabled for frontend access

Setup

1. Install dependencies:

pip install -r requirements.txt

2. Configure environment (optional):

cp .env.example .env
# Edit .env with your settings

3. Run the server:

python app.py

The server will start on http://localhost:5000

API Endpoints

Authentication

• POST /api/auth/login - Login with username/password
• POST /api/auth/logout - Logout current session

Containers

• GET /api/containers - List all containers (requires auth)
• POST /api/containers/<id>/exec - Execute command in container (requires auth)

Health

• GET /api/health - Health check

Docker

Build the Docker image:

docker build -t docker-swarm-backend .

Run the container:

docker run -p 5000:5000 -v /var/run/docker.sock:/var/run/docker.sock docker-swarm-backend

Debugging

The application includes comprehensive Docker connection diagnostics that run automatically on startup. Check the logs for:

• Docker environment variables (DOCKER_HOST, DOCKER_CERT_PATH, etc.)
• Docker socket existence and permissions
• Current user and group information
• Connection attempt results

Example output:

=== Docker Environment Diagnosis ===
DOCKER_HOST: unix:///var/run/docker.sock
✓ Docker socket exists at /var/run/docker.sock
Socket permissions: 0o140777
Readable: True
Writable: True
Current user: root (UID: 0, GID: 0)
✓ Successfully connected to Docker using Unix socket
✓ Docker connection verified on startup

If connection fails, the diagnostics will show detailed information about what's wrong.

CapRover Deployment

For deploying to CapRover (which uses Docker Swarm), see the detailed guide in CAPROVER_DEPLOYMENT.md.

Key points:

• Uses captain-definition file with serviceUpdateOverride to mount Docker socket
• Runs as root to access Docker socket
• Includes enhanced debugging for troubleshooting connection issues
• Only supports 1 replica (Docker socket can't be shared)

Security

⚠️ This backend requires access to the Docker socket. Ensure proper security measures are in place in production environments.

Security Considerations:

• Container has root access to the host system via Docker socket
• Implement strong authentication (change default credentials)
• Restrict network access to the API
• Only use in trusted environments
• Monitor logs for suspicious activity
• Consider using a Docker socket proxy for additional security