hausgold/mdns-proxy repository overview

This Docker images provides a simple proxy for tunneling requests to mDNS-enabled Docker containers via a single endpoint. This allows bridging regular DNS to mDNS name resolution transparently. The usage of this software may be useful in various situations, eg. using it together with Dnsmasq⁠ on macOS (with Docker for Mac) or as an regular entrypoint to a virtual machine or on a remote cloud instance.

A simple example setup requires a virtual machine, some mDNS-enabled containers running inside of it, this software running also inside of the virtual machine and some host entry configurations.

• Requirements⁠
• Getting starting⁠
• docker-compose usage example⁠
• Rebind another external DNS suffix⁠

⁠Requirements

• A dedicated host where some mDNS-enabled containers are running (which will be made available on a single port of the host)

⁠Getting starting

You just need to run it like that, to get a working ruby:

$ docker run -p 80:80 --rm hausgold/mdns-proxy

The binded host port is then linked to the mDNS proxy which will handle requests with various host headers (eg. test.local).

⁠docker-compose usage example

services:
  ruby:
    image: hausgold/mdns-proxy
    environment:
      # The default, see "Rebind another external DNS suffix"
      MDNS_SUFFIX: .local
      # These root path entries will be upgraded to WebSocket
      # connections transparently. The following list is the default.
      WEBSOCKET_PATHS: 'cable|sockjs-node|livereload|ws'
      # Change the maximum upload size per request
      MAX_UPLOAD_SIZE: 20m

⁠Rebind another external DNS suffix

You can modify the incomming host names by reconfiguring the MDNS_SUFFIX which defaults to .local. This way you can transparently rebind the host to a different DNS name. Say you have an AWS EC2 instance with some mDNS-enabled containers running and bind an IP to it. Setup an A DNS record for it like example.com and a wildcard to the very same host. Then you set MDNS_SUFFIX='.example.com' here and your can access your mDNS containers like this: app.example.com.