KUBE_PING warning with StatefulSet

[jmesnil]

The WildFly Operator is using a StatefulSet to deploy application on Kubernetes/OpenShift.

It was possible to use KUBE_PING with WildFly 17 (and the JGroups version that it integrated) but there is a new warning with WildFly 18 during the deployment of the application:

08:46:20,187 WARN  [org.jgroups.protocols.kubernetes.KUBE_PING] (thread-17,ejb,clusterbench-1) metadata.labels.pod-template-hash not found in pod json. Impossible to reliably determine pod group during Rolling Update

Indeed pod-template-hash label is set only for pods coming from a Deployment[1] and is not present when a StatefulSet is used.

Is this warning by design or should KUBE_PING work with StatefulSets without any issue?

[1] https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#pod-template-hash-label

[jmesnil]

WildFly 18 uses jgroups-kubernetes 1.0.12.Final
WildFly 17 uses jgroups-kubernetes 1.0.9.Final

[rhusar]

I am not sure, are you just seeing a warning or does the discovery not work?

The change that introduced this is be3d733

[jmesnil]

@rhusar I edit the issue, I thought it was not working but I was not patient enough for the cluster to be formed :)

So, it's working but it logs this warning

[slaskawi]

@jmesnil @rhusar The clustering should work fine, however, you won't be able to separate deployments during rolling update (see split_clusters_during_rolling_update property). I believe we'll need to enhance this feature to support StatefulSets as well.

[rhusar]

The WF Jira for this is https://issues.jboss.org/browse/WFLY-12657.