How to deploy Zookeeper on Kubernetes - Liveness probe failed "The list of enabled four letter word commands is : [[srvr]]"

Question

Hello I try to deploy Zookeeper in Kubernetes with this yaml file:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: zookeeper-cluster-import-deployment
  namespace: mynamespace
  labels:
    name : zookeeper-cluster-import
    app : zookeeper-cluster-import
spec:
  replicas: 1
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: zookeeper-cluster-import
  template:
    metadata:
      labels:
        app: zookeeper-cluster-import
    spec:
      restartPolicy: Always
      containers:
      - name: zookeeper
        image: dockerbase_zookeeper:v01
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 2181
          name: zookeeper
        env:
          - name: ALLOW_ANONYMOUS_LOGIN
            value: "yes"
          - name: ZOO_4LW_COMMANDS_WHITELIST
            value: "ruok"
        livenessProbe:
             exec:
                command: ['/bin/bash', '-c', 'echo "ruok" | nc -w 2 localhost 2181 | grep imok']
             initialDelaySeconds: 60
             periodSeconds: 10
             timeoutSeconds: 5
             failureThreshold: 6
             successThreshold: 1
        readinessProbe:
             exec:
                command: ['/bin/bash', '-c', 'echo "ruok" | nc -w 2 localhost 2181 | grep imok']
             initialDelaySeconds: 120
             periodSeconds: 10
             timeoutSeconds: 5
             failureThreshold: 6
             successThreshold: 1
        resources:
          requests:
            cpu: 400m
            memory: 2Gi
          limits:
            cpu: 500m
            memory: 2Gi
        securityContext:
          allowPrivilegeEscalation: false
          privileged: false
          runAsGroup: 1000
          runAsUser: 1000
      imagePullSecrets:
      - name: secret-repos
      volumes:
      - name: pv-01
        persistentVolumeClaim:
          claimName: pv-claim-01

But when I apply this yaml I have "Liveness probe failed" and in the pod logs I see at the end of the logs : The list of enabled four letter word commands is : [[srvr]]

I don't understand because in env I did :

      - name: ZOO_4LW_COMMANDS_WHITELIST
        value: "ruok"

It is like the command is not recognized.