Enabling External Access to Cluster

6.0-SNAPSHOT 5.5 5.4 5.3 5.2 5.1 5.0

Hazelcast Helm chart Cluster topology enables external access to any of the pods via any Hazelcast client. The external access is not enabled by default. It can be enabled during deployment or by upgrading after deployment. Scaling down or scaling up via upgrading automatically removes or adds external services for the members.

For external access to work correctly, each LoadBalancer service must get its external address before the matched member starts running. For this, you can use an init container that will wait for services to get their external IPs.

To enable the external access feature, you should configure the values.yaml as following. Please note that you need to give values for <LABEL_NAME> and <LABEL_VALUE>.

hazelcast:
  yaml:
    hazelcast:
      network:
        join:
          kubernetes:
            service-per-pod-label-name: <LABEL_NAME>
            service-per-pod-label-value: <LABEL_VALUE>

externalAccess:
  enabled: true
  service:
    labels:
      <LABEL_NAME>: <LABEL_VALUE>

initContainers:
  - name: wait-for-lb
    image: bitnami/kubectl:1.22
    env:
      - name: POD_NAMESPACE
        valueFrom:
          fieldRef:
            fieldPath: metadata.namespace
      - name: POD_NAME
        valueFrom:
          fieldRef:
            fieldPath: metadata.name
    command:
      - "sh"
      - "-c"
    args:
      - until [ -n "$$(kubectl get svc -n $${POD_NAMESPACE} -l <LABEL_NAME>=<LABEL_VALUE> -ojsonpath="{.items[?(@.spec.selector.statefulset\.kubernetes\.io/pod-name==\"$${POD_NAME}\")].status.loadBalancer.ingress[0].ip}")" ]; do sleep 8; done

This configuration will create (by default) 3 LoadBalancer services one for each Hazelcast member since default value of member count for Hazelcast cluster is 3. For a full working example you can follow the Kubernetes External Access Tutorial.

If you want to use external access feature without manual configuration, you can start using Hazelcast Platform Operator.
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