Add user@address:port support

[mkg20001]

Adds support for #1994

Also fixes some issues with #1572 by adding debug logs that say why a machine was skipped

Note: There's some incomplete stuff and I also have no (actual) clue about C++ so I'd appreciate help

[edolstra]

Not really opposed to this, but it's a lot of code to support something that can already be achieved via ssh_config.

[mkg20001]

I'll move the additional debug logs to another PR

Right now just IPv6 support is missing

Meanwhile I learned how to C++, so that's why that took so long

[stale]

I marked this as stale due to inactivity. → More info

[stale]

I closed this issue due to inactivity. → More info

[tomberek]

Still interested

[vincentbernat]

There is already code for compression and SSH key, both of them can also be set in ssh_config. One can also use NIX_SSHOPTS. I am also interested into this to make darwin.builder work on another port than 22. I think the idea to support it in the URI of the builder is to avoid messing with too many user files.

[Ericson2314]

Note if we do this, we should also consider doing it with

Use the same notion of a Machine config for remote builders.

from NixOS/hydra#1164

This syntax would be used in the build machines files too, and we don't want that to drift further apart between Nix and Hydra.

[mkg20001]

Currently I've got no intention of updating this pr, so feel free to force push / make a new one

(I should mention again I barely know c++ so it would be a pita for me to code this to the end anyways)

[Ericson2314]

OK, very understandable after 3 years! I converted it to a draft.

[Ericson2314]

Discussed last Nix team meeting.

Verdict: Idea sounds good. Port parsing however should be pat of the URL parser in general, not extracted in this special case. Stores that don't support ports can just fail on that; stores that do like this one can set it very easily.

[nixos-discourse]

This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/2023-04-10-nix-team-meeting-minutes-47/27357/1

[Ericson2314]

OK this PR is on the right track now, but it is not yet ready:

1. Restore passing the user part of the URL to stores, get rid of authHack tricks.
2. Tests if possible
3. Release notes