The Confluence Helm Chart documents:

synchrony:
  # Port definitions
  #
  ports:

    # -- The port on which the Synchrony container listens for Hazelcast traffic
    #
    hazelcast: 5701

However, changing the above value to a custom value such as Port 5301 will have no effect on the Hazelcast port that Synchrony listens or discover other nodes on.

The cause of this is that:

• -Dcluster.listen.port=<SYNCHRONY_HAZELCST_PORT> is not passed as a JVM flag to Synchrony process
• Hazelcast Kubernetes Discovery API appears to utilise the HAZELCAST_KUBERNETES_SERVICE_PORT environment value for the Port number to discover other nodes. When this environment variable is not set, it defaults to 5701.

Suggestion:

Update the Helm Chart deployment to automatically:

• Set the -Dcluster.listen.port= to the value in synchrony.ports.hazelcast
• Set the HAZELCAST_KUBERNETES_SERVICE_PORT environment variable to the value in synchrony.ports.hazelcast

from the Helm chart values.

Workaround:

Set the following values in the Confluence DC Helm Chart values:

synchrony:
  ports:
    hazelcast: 5301

  additionalJvmArgs:
    - -Dcluster.listen.port=5301

The Confluence DC Helm Chart does not currently support custom Environment Variables for Synchrony. The only way to update environment variables would be to manually download and update the local <Confluence Helm Chart>/templates/_helpers.tpl file and then manually deploy the local Confluence Helm Chart.