dockerproxy

README

Luzifer / dockerproxy

DockerProxy is a small application to shield HTTP exporting Docker containers. The proxy supports SNI to shield the containers with HTTPs certificates. To discover the containers the Docker daemon needs to listen on a tcp port which should be shielded by a firewall to ensure the security of the Docker host.

Design Flaw

Currently Docker does not support container tagging so this proxy is using the environment variables to detect the "slug" and the port of a container. This can be fixed as soon as there is a tagging concept similar as the EC2 tagging in AWS.

Configuration

Docker daemon

• Ensure the daemon is listening on a tcp port reachable from the dockerproxy. In this example port 9999 is used.
• Start your docker containers with some special environment variables used for container detection:
  • ROUTER_SLUG: The slug used in the proxy configuration to identify the container
  • ROUTER_PORT: The public exported HTTP port the proxy can send its requests to

dockerproxy

The configuration is written in JSON format and read every minute by the daemon:

• domains: Dict of domain configurations the proxy is able to respond to
  • slug: The slug defined in the Docker container to determine which container should handle the request
  • force_ssl: The proxy does not forward request but return a redirect to SSL based connection
  • ssl (optional): SSL configuration for that domain
    • cert: x509 certificate file (Intermediate certificates belongs in this file too. Put them under your own certificate.)
    • key: The key for the cerficate without password protection
• generic: A generic suffix on which the proxy will forward to every configured container
• listenHTTP: An address binding for HTTP traffic like :80
• listenHTTPS: An address binding for HTTPs traffic like :443
• docker: Docker host configuration
  • hosts: Dict of private to public host/ip associations (The Proxy will query the Docker daemon on the private host/ip and send traffic to the public host/ip)
  • port: Port to use for querying the Docker daemon

Example configuration:

{
  "domains": {
    "host1.example.com": {
      "ssl": {
        "cert": "ssl/host1.example.com.crt",
        "key": "ssl/host1.example.com.key"
      },
      "slug": "container1",
      "force_ssl": true
    },
    "host2.example.com": {
      "slug": "container2"
    }
  },
  "generic": ".dockersrv.example.com",
  "listenHTTP": ":8081",
  "listenHTTPS": ":4443",
  "docker": {
    "hosts": {
      "localhost": "docker01.servers.example.com"
    },
    "port": 9999
  }
}