Description of problem:

In ACM2.6.x it was possible to resolve a Submariner headless service to the IP address of the backing pod during a container booting sequence before the pod and service was marked as ready.

This logic is required by software such as Postgres-HA (bitnami distribution) in which the replication manager specifically checks the connection network string (derived from the headless service name) as part of the booting sequence.

This change in behaviour was detected in ACM2.7.x and most likely due to this errata:

https://issues.redhat.com/browse/ACM-3751

Version-Release number of selected component (if applicable):

ACM2.7.x

How reproducible:

Easily

Steps to Reproduce:

1. https://content.cloud.redhat.com/blog/guide-to-cluster-landing-zones-for-hybrid-and-multi-cloud-architectures-part-2
2.  
3. ...

Actual results:

2023-05-19 12:28:18.057 GMT [148] LOG:  checkpoint complete: wrote 3 buffers (0.0%); 0 WAL file(s) added, 0 removed, 0 recycled; write=0.004 s, sync=0.002 s, total=0.017 s; sync files=2, longest=0.001 s, average=0.001 s; distance=0 kB, estimate=0 kB
2023-05-19 12:28:18.061 GMT [146] LOG:  database system is ready to accept connections
 done
server started
postgresql-repmgr 12:28:18.10 INFO  ==> ** Starting repmgrd **
[2023-05-19 12:28:18] [NOTICE] repmgrd (repmgrd 5.3.3) starting up
[2023-05-19 12:28:18] [ERROR] connection to database failed
[2023-05-19 12:28:18] [DETAIL]
could not translate host name "pg-1-postgresql-ha-postgresql-0.red-cluster-pool-aws-1-qf52t.pg-1-postgresql-ha-postgresql-headless.database.svc.clusterset.local" to address: Name or service not known[2023-05-19 12:28:18] [DETAIL] attempted to connect using:
  user=repmgr password=redhat123 connect_timeout=30 dbname=repmgr host=pg-1-postgresql-ha-postgresql-0.red-cluster-pool-aws-1-qf52t.pg-1-postgresql-ha-postgresql-headless.database.svc.clusterset.local port=5432 fallback_application_name=repmgr options=-csearch_path=

Expected results:

Postgres and replication manager should start successfully as per ACM2.6.x

Additional info: