Install Operator

kubectl apply -f "https://github.com/rabbitmq/cluster-operator/releases/latest/download/cluster-operator.yml"
# namespace/rabbitmq-system created
# customresourcedefinition.apiextensions.k8s.io/rabbitmqclusters.rabbitmq.com created
# serviceaccount/rabbitmq-cluster-operator created
# role.rbac.authorization.k8s.io/rabbitmq-cluster-leader-election-role created
# clusterrole.rbac.authorization.k8s.io/rabbitmq-cluster-operator-role created
# rolebinding.rbac.authorization.k8s.io/rabbitmq-cluster-leader-election-rolebinding created
# clusterrolebinding.rbac.authorization.k8s.io/rabbitmq-cluster-operator-rolebinding created
# deployment.apps/rabbitmq-cluster-operator created

Define an instance 
Mqinstance.yaml:

apiVersion: rabbitmq.com/v1beta1
kind: RabbitmqCluster
metadata:
  name: production-ready
spec:
  replicas: 1
  resources:
    requests:
      cpu: 1
      memory: 1Gi
    limits:
      cpu: 1
      memory: 1Gi
  rabbitmq:
    additionalConfig: |
      cluster_partition_handling = pause_minority
      disk_free_limit.relative = 1.0
      collect_statistics_interval = 10000
  persistence:
    storageClassName: csi-rbdfs-sc
    storage: "5Gi"
  affinity:
    podAntiAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
      - labelSelector:
          matchExpressions:
            - key: app.kubernetes.io/name
              operator: In
              values:
              - production-ready
        topologyKey: kubernetes.io/hostname
  override:
    statefulSet:
      spec:
        template:
          spec:
            containers: []
            topologySpreadConstraints:
            - maxSkew: 1
              topologyKey: "topology.kubernetes.io/zone"
              whenUnsatisfiable: DoNotSchedule
              labelSelector:
                matchLabels:
                  app.kubernetes.io/name: production-ready