Read-only replicas

[davidfrickert]

Is your feature request related to a problem? Please describe. I would like to have a LDAP cluster that is writable on-cluster by other connected apps but not writable from operations from outside the cluster.

Describe the solution you'd like Allow adding read-only replicas. They should be a separate StatefulSet and receive updates from the master cluster. Then, I can create a LoadBalancer service that exposes only the read-only pods to outside network.

Describe alternatives you've considered N/A

Additional context In order for the replica to be read only, olcReadonly: TRUE needs to be set - https://openldap.org/doc/admin24/slapdconf2.html (5.2.5.3. olcReadonly)