Support multiple named sockets in service block

[owenthereal]

Verification

• This issue's title and/or description do not reference a single formula e.g. brew install wget. If they do, open an issue at https://github.com/Homebrew/homebrew-core/issues/new/choose instead.

Provide a detailed description of the proposed feature

It would be nice to declare multiple sockets with names in the service block in a formula. For example:

service do
  sockets "Socket" => "tcp://0.0.0.0:80", "SocketTLS" => "tcp://0.0.0.0:443"
end

What is the motivation for the feature?

Some formulas may expose multiple sockets in a plist file. For example, owenthereal/homebrew-candy@92aada6 tries to convert the old plist function with both port 80 and 443 set in the Sockets plist section but couldn't due to sockets in the service block only allows one entry, although sockets with an s.

How will the feature be relevant to at least 90% of Homebrew users?

This prevents some formula that requires exposing multiple sockets from working. I don't have a number on the number of Homebrew users impacted. But the migration from plist to service breaks some formulas.

What alternatives to the feature have been considered?

I do not know a way. Please share if you have any recommendations.

[MikeMcQuaid]

Makes sense to me. What do you think @SMillerDev?

[apainintheneck]

I looked at the code yesterday and the sockets stanza seems to only be available for launchd on MacOS right now. I think it's a no-brainer. I'm not sure why it was never added to the systemd on the Linux side though. I'm not sure why we don't allow people to name their sockets either or how useful that would be to add in.

[SMillerDev]

Yeah, seems fine to me. I never added it because no formulae I knew of needed it.

[apainintheneck]

@owenthereal It would be great if you could test out the changes on this branch (#16026) to make sure they solve the problem. Also, I looked at your formula and you'll want to use service do instead of def service when defining a service.

[owenthereal]

@apainintheneck Sorry for not getting back to you sooner. I saw the changes were reverted. I'm happy to help test it when it's ready again. I don't know how to test a branch's code changes. Is there a doc that I could take a look at?

[apainintheneck]

@owenthereal No worries. I just like to double-check with people who open issues to see if it fits their use case. I'll fix and reopen the original PR in the next few days and ping you so that you can take a look at it when that's ready.

I don't think we have documentation for that but that sounds useful since this comes up from time to time. Brew is just a git repo of Ruby code so it's not terribly complex to check out a feature branch locally for testing. I'll provide instructions for testing it in the PR.