Support unix: URLs for docker socket as well as http/https

[sshipway]

This would allow the use of

-v /var/run/docker.sock:/var/run/docker.sock ...  --mccy.docker-host-uri=unix:///var/run/docker.sock 

when starting the container, which removes the need to expose your Docker API to a TCP port that may be accessed from somewhere else.

[itzg]

Awesome, the Spotify library does also support UNIX sockets. In fact, the example you show with a unix:// URI should work already.

[sshipway]

I've already tried, and the code denies anything not starting "http". I think this is your code, though:

default message [The DOCKER_HOST URI must be HTTP or HTTPS]

[itzg]

Doh, it is my code applying a regex to the config field. That's easy to fix :)