feat: Add Windows Service support

[fkollmann]

This PR adds support for running the Cloud SQL Proxy as Windows service.

More details on how to install, can be found in the windows-service-guide.md file.

Tested on Windows Server 2019.

If the executable is run from the command line directly, it will run normally like before.

Please see it as a first draft based on my multi-year experience with running Go apps as Windows services.

Open questions are:

• Do we need an installer? (WiX, Nullsoft)
• Should the path of the logfile be changeable?
• Should the Windows Event Log be used for logging (requires installer to be feasible)?

Implements #277

[conventional-commit-lint-gcf]

🤖 I detect that the PR title and the commit message differ and there's only one commit. To use the PR title for the commit history, you can use Github's automerge feature with squashing, or use automerge label. Good luck human!

-- conventional-commit-lint bot
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[enocom]

Wow! Thanks for this PR! I'll take a look today.

[enocom]

Generally looks good to me.

Tests would be nice ;-)

A few questions and minor suggestions.

[enocom]

And to answer you questions:

Do we need an installer? (WiX, Nullsoft)

For now, installing from the Releases page seems fine to me.

Should the path of the logfile be changeable?

This is also easy to change in the future, so I'm inclined to start with a hard-coded path and update if there's interest.

Should the Windows Event Log be used for logging (requires installer to be feasible)?

Might be another nice enhancement, but we can ship this once we work through review. So I'm ok with not doing this yet.

[enocom]

@fkollmann Friendly ping.

If you'd like some help getting this finished, let me know. You've already done the majority of the work. 😄

[fkollmann]

@fkollmann Friendly ping.

Thank you. Sry, I was busy playing Diablo IV beta this weekend 😅. I will get back to you on Thursday.

[enocom]

😆 No worries. Again this is a helpful contribution, so I'm happy to lend a hand wherever needed.

[fkollmann]

I went through the comments and see no major issues, besides a minor misunderstanding on Windows services. I will answer the comments tomorrow and make some changes.

[fkollmann]

Short update: I had to change plans for the weekend. I have time for providing feedback today.

[fkollmann]

I did some code changes and marked the suggestions as resolved. (Please let me know if I should have kept the suggestions unresolved, or not).

Looking forward to your feedback.

[enocom]

Sorry for the slow response. I'll get to this soon.

[fkollmann]

Don't worry. No pressure from my side.

We are currently using it on production, so it at least works for us 😅

[enocom]

Currently running this through some manual tests. We can probably get this into the next release.

[enocom]

Looks great. Just a few comments.

Do we need to add a note about UAC as a possible thing to investigate if it doesn't work?

[enocom]

@fkollmann There are a few small changes to make here that I'm going to do. And then I'll merge this.

[enocom]

Looks like I can't push to your fork. You can change that, though. See here.

Alternatively, aside from the two typos @jackwotherspoon pointed out, we need to keep a main.go and just add a //go:build !windows at the top, so we can keep building for Unix-based OSes.

[fkollmann]

Hi, sry, I was on vacation the last week, incl today. I will look into this tomorrow. Have a nice evening :) . Best Regards, Felix

[fkollmann]

Looks like I can't push to your fork. You can change that, though. See here.

That is currently not support with forks below other organizations (instead of individual users). However, I granted you maintainer permissions on the repo.

[fkollmann]

Okay, I addressed everything, from my POV. Please feel free to comment (and change). @enocom

[enocom]

Looks great! Thanks again for this contribution!