[Feature/Operator] Specific Liveness & Readiness command

[juldrixx]

From nifikop created by erdrix: Orange-OpenSource/nifikop#5

Feature Request

Is your feature request related to a problem? Please describe.

In the current solution, the readiness & liveness simply call the nifi-api and check if a response from nifi node is here. Because of the need to check if the node is in the cluster to say "it is ready", this will cause issues when we decommission the node.

Describe the solution you'd like to see

As we are working at the pod level, we could imagine checking if the node is part of the cluster in normal cases, and in the case of a decommissioned node, changing the liveness and readiness script to check if we can target it?