docker-ddns

This project provides dynamic DNS updates for Docker containers. It listens for Docker container start events and automatically updates DNS records for containers with the appropriate labels.

Features

• Listens for Docker container start events in real time (no polling)
• Updates DNS records using RFC2136 for containers with ddns.enable label and Traefik host rules
• Configurable via Docker secrets or environment variables

Usage

1. Build the Docker image:

   docker build -t docker-ddns .

2. Run the container:

   docker run --rm \
     -v /var/run/docker.sock:/var/run/docker.sock \
     -e DNS_HOST=your_dns_server \
     -e TSIG_NAME=your_tsig_name \
     -e TSIG_KEY=your_tsig_key \
     -e VALID_DOMAINS=example.com \
     -e HOST_IP=1.2.3.4 \
     docker-ddns

3. Label your containers:

   • Add ddns.enable=true and a Traefik host rule label to any container you want to manage DNS for.

How it works

• The service listens to Docker events and triggers a DNS update when a new container is started.
• Only containers with the ddns.enable=true label and a valid Traefik host rule are processed.

Environment Variables / Secrets

• DNS_HOST: DNS server address
• DNS_PORT: DNS server port (default: 53)
• TSIG_NAME: TSIG key name
• TSIG_KEY: TSIG key value
• TSIG_ALGO: TSIG algorithm (default: HMAC-SHA256)
• VALID_DOMAINS: Comma-separated list of valid domains
• HOST_IP: IP address to assign in DNS records
• DOCKER_URL: (optional) Docker socket URL

Requirements

• Docker socket must be mounted (-v /var/run/docker.sock:/var/run/docker.sock)
• Python 3.13+ (if running outside Docker)

License

MIT