Support unix socket in client

[SamMousa]

Proposal

The go API client doesn't support unix sock, I tested this by testing the CLI:

NOMAD_ADDR=unix://$(pwd)/api.sock nomad agent-info
Error querying agent info: failed querying self endpoint: Get "unix:///v1/agent/self?namespace=cluster": unsupported protocol scheme "unix"

Use-cases

The recently added api.sock unix socket is great, I'd like to be able to use it Traefik service discovery: traefik/traefik#10044

Attempted Solutions

An alternative would be to expose the unix socket as a tcp socket, but this requires yet another proxy process. Also to do this securely I'd need to have both processes (containers in my case) run in the same network space; it gets complicated quickly.

Currently I use this: http://host.docker.internal:4646 but that only works because my current 3 nodes are both clients and servers.
I can't use a public URL since that is one of the things traefik is reverse-proxying for me.

I inspected the Traefik source code, and all they do is import your API client and set its address config option, which is what leads me to believe this issue should be in this tracker.

[tgross]

Hi @SamMousa we've already got a PR open for that: #16872 It's been approved but I think @angrycub just had a few more tweaks he wanted to do before we merge it.