(machine) How to go about having two gagent subords related to the same principal about grafana-agent-k8s-operator

[rbarry82]

Yes, but that's what we want, since the subordinate is "really" running on the principal machine. We could set a limit so they don't walk over each other's configs, though, but this is probably a "don't do that" item which almost nobody will try in real life.

The snap library itself is idempotent, though, and if it's already installed, the worst that happens is that it tries to refresh it when we try to ensure it's the latest version. If it's already on the principal, this is a noop.

That said, the assumption that an operator will manually install the snap on some other charm is pretty antithetical to normal cloud operations, and the same "what if an admin juju ssh-es into a machine and initializes postgres/kafka/changes the PAM configuration/etc" are potential risks/"don't do that" in all charms which are not meaningful/supportable scenarios.

[rbarry82]

This PR will permanently resolve this.

[sed-i]

Afaict, that PR does not address the race in writing config files.
But I'm fine with placing it in the "don't do that" bin.

[rbarry82]

No, it doesn't. But "I related two grafana-agent charms to the same principal on different subordinates and they're thrashing the same config file" probably equally applies to, like... the entire category of subordinates, honestly.

[dstathis]

We have no way to stop. It will obviously break if you do it. As Ryan said, that is probably true of every subordinate ever.

[sed-i]

Ok. Let's tackle this in the docs, if at all. Closing.

[sed-i]

Do you think we should recommend limit: 1 for cos-agent provider (kafka, zk, ...)?
cc @Abuelodelanada

[rbarry82]

I guess the question is, somewhat "what are the odds?"

It wouldn't hurt to sneak it into a PR, but it's probably low priority enough not to deserve an issue on its own IMO

[Abuelodelanada]

Do you think we should recommend limit: 1 for cos-agent provider (kafka, zk, ...)?
cc @Abuelodelanada

My gut feeling is that there is no point in having more than one.