chore: add probes on all containers

[zwindler]

Hello,

I'm deploying this exporter on my cluster and we have a Kyverno policy that requires all pods to have liveness/readiness probes

Since those are exporters containers, I felt it was not a bad thing to make sure that the exporter is indeed listening on the exposed port

It's best practice to not have liveness === readiness but in this case I think this is acceptable, unless you want to take the time to create proper HTTP endpoints in the code to add a /live and a /ready (I can do it but I'm not sure this is worth it)

[paullaffitte]

Hi! Thanks for your contribution!

The /metrics endpoint generate metrics on the fly, so relying on it for probes isn't very cost-efficient. Could you add and use a /healthz endpoint instead? The liveness and readiness probes can both rely on it. You don't have to implement any logic, in the futur we could think about implementing some real checks, but for now simply responding would be enough.

[zwindler]

Sure, that makes much more sense

I'll work on this soon and will update the branch

[zwindler]

@paullaffitte I added a super basic handler to the ServeMux (/healthz as suggested)