server: can't hook initialization steps past cluster settings propagation

[knz]

This is stalling progress on e.g. #17020: I can't find a place in the code to put an initialization steps that runs 1) after the cluster settings are loaded / propagated via gossip but 2) before the server is ready for client connections.

There should be a hook in the code, clearly documented as such, where one can add initialization code.

@dt suggests:

I'd probably go for the nonblocking write to a chan struct{} in settingsworker.go, the add a read (maybe w/timeout) to the startup path in server (maybe wrapped in a helper). could also go with a waitgroup if you made sure to only call Done the first time, or a cond var? not a perf-sensitive code path, so I would probably take simple over fast.

Unfortunately I was not myself able to translate this into code.

[bdarnell]

Potentially related to reworking of the server startup flow in #16371

[github-actions]

We have marked this issue as stale because it has been inactive for
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or adding a comment will keep it active. Otherwise, we'll close it in
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[ajwerner]

I believe this is stale. We load settings before accepting client connections now IIUC. At least in secondary tenants this definitely happens and I'm working on unifying the behavior in #69269. I don't think this issue is providing anybody with value so I'm going to close it.