There should be a new endpoint for the operator readiness probe

There should be a new endpoint /readiness-probe/ that checks configuration/connection to couchbase server by pinging /pools/default with credentials/config and ensures a 200 response. Keep in mind that the /metrics endpoint may be protected by token and/or tls. The /readiness-probe/ endpoint should be similarly protected.

The goal is to remove the Operator's reliance on the /metrics endpoint for readiness as the scrape of /metrics is an expensive operation