Support binding to a unix domain socket instead of a TCP address in serve-web

[leifwalsh]

It doesn't look like this new CLI supports serving on a UNIX domain socket. Could we please get that added in too, like in microsoft/vscode-remote-release#6940? We're going to need it in order to handle auth in a proxy. (I'm happy to open a new issue for that if you need)

Originally posted by @leifwalsh in #191014 (comment)

[leifwalsh]

Nice, thanks!

[roblourens]

I can do this

$ code-insiders serve-web --socket-path /tmp/mysock
*
* Visual Studio Code Server
*
* By using the software, you agree to
* the Visual Studio Code Server License Terms (https://aka.ms/vscode-server-license) and
* the Microsoft Privacy Statement (https://privacy.microsoft.com/en-US/privacystatement).
*
Web UI available on /tmp/mysock

what now?

[roblourens]

Also is it an issue that the socket file wasn't release/deleted after a ctrl+C? [2023-08-29 11:24:41] error could not listen on socket/pipe: Os { code: 48, kind: AddrInUse, message: "Address already in use" } or do I clean that up manually?

[connor4312]

We should probably automatically delete the file if it exists

what now?

You can do a curl to make sure it's actually working curl --unix-socket /tmp/mysock http:/localhost. Without extra stuff you won't be able to open it in the browser, but verifying the connection should be enough.