The problem is that your service type is ClusterIP which is not available from outside the Kubernetes cluster. There are two ways you could do this
If you need to really access this regularly from outside the cluster, you should deploy a service of type NodePort or LoadBalancer or an ingress. These would be reachable from outside
If you only want to check something quickly, you can temporarily make zookeeper visible with

kubectl port-forward zookeeper-0 2181