I've got a problem regarding getting service port in DNS_PING DNS lookup.
It seems in my openshift environment the JNDI DNS lookup cannot query the
correct SRV record from the openshift DNS server. Ref:

https://github.com/jboss-openshift/openshift-ping/blob/1.2.1.Final/dns/src/main/java/org/openshift/ping/dns/GetServicePort.java#L48

For example, here is the ping service:

apiVersion: v1
kind: Service
metadata:
annotations:
description: The JGroups ping port for clustering.
service.alpha.kubernetes.io/tolerate-unready-endpoints: 'true'
labels:
application: application0
template: amq-broker-73-persistence-clustered
xpaas: 1.4.16
name: application0-ping
spec:
clusterIP: None
publishNotReadyAddresses: true
ports:

port: 8888
protocol: TCP
name: jgroup-port
targetPort: 8888
selector:
deploymentConfig: application0-amq

After it is deployed I deployed a application pod
with JGroups DNS_PING protocol loaded. The relevant
jgroups xml part looks like this:

<config> ... <openshift.DNS_PING timeout="3000" serviceName="application0-ping" /> ... </config>

After my application pod is in running state, I checked the log
and there is a warning message from DNS_PING:

2019-07-22 04:16:59,600 INFO [org.openshift.ping.common.Utils] 3 attempt(s) with a 1000ms sleep to execute [GetServicePort] failed. Last failure was [java.lang.NullPointerException: null]
2019-07-22 04:16:59,601 WARNING [org.jgroups.protocols.openshift.DNS_PING] No DNS SRV record found for service [application0-ping]

After some debugging it turns out that the DNS lookup for the record by this name
"_tcp.application0-ping" returned null.

However if I logged into the application pod and do nslookup it will give me correct record:

sh-5.0# nslookup -type=srv _tcp.application0-ping
Server: 10.74.177.77
Address: 10.74.177.77#53

_tcp.application0-ping.default.svc.cluster.local service = 10 100 8888 44c84e52.application0-ping.default.svc.cluster.local.

And you can get the full name from the record, which is

_tcp.application0-ping.default.svc.cluster.local

If I then pass the full qualified name into the application and it can query the SRV
record successfully.

I have no idea why my application can't query the record using the short form name (i.e. _tcp.application0-ping). Could it be some configuration issue for the DNS ping?

My openshift env details are:

oc v3.11.117
kubernetes v1.11.0+d4cacc0
features: Basic-Auth GSSAPI Kerberos SPNEGO

and the java version used in pod:

sh-5.0# java -version
openjdk version "1.8.0_212"
OpenJDK Runtime Environment (build 1.8.0_212-b04)
OpenJDK 64-Bit Server VM (build 25.212-b04, mixed mode)

and the base OS is fedora 30.