Issue 7287 zookeeper testing probes (kubernetes#7290)

* Replace old zkOk.sh livenessProbe by zookeeper-ready

Fixes one part of the issue kubernetes#7287

* Update probe script content with the zookeeper-ready

Fixes the part with shows/explains the probe script at issue kubernetes#7287

* Fix the path to delete liveness probe

Issue kubernetes#7287

* Replace zkOk.sh readinessProbe by zookeeper-ready

Fixes "Testing for Readiness" section in issue kubernetes#7287

Author: rgo

docs/tutorials/stateful-application/zookeeper.md

@@ -798,7 +798,9 @@ The Pod `template` for the `zk` StatefulSet specifies a liveness probe.
  livenessProbe:
           exec:
             command:
-            - "zkOk.sh"
+            - sh
+            - -c
+            - "zookeeper-ready 2181"
           initialDelaySeconds: 15
           timeoutSeconds: 5
 ```
@@ -809,8 +811,7 @@ word to test the server's health.
 
 
 ```bash
-ZK_CLIENT_PORT=${ZK_CLIENT_PORT:-2181}
-OK=$(echo ruok | nc 127.0.0.1 $ZK_CLIENT_PORT)
+OK=$(echo ruok | nc 127.0.0.1 $1)
 if [ "$OK" == "imok" ]; then
     exit 0
 else
@@ -831,7 +832,7 @@ In another window, delete the `zkOk.sh` script from the file system of Pod `zk-0
 
 
 ```shell
-kubectl exec zk-0 -- rm /opt/zookeeper/bin/zkOk.sh
+kubectl exec zk-0 -- rm /usr/bin/zookeeper-ready
 ```
 
 
@@ -875,7 +876,9 @@ probe from the `zookeeper.yaml` manifest is identical to the liveness probe.
  readinessProbe:
           exec:
             command:
-            - "zkOk.sh"
+            - sh
+            - -c
+            - "zookeeper-ready 2181"
           initialDelaySeconds: 15
           timeoutSeconds: 5
 ```