zkOk.sh

#!/usr/bin/env bash
# Copyright 2016 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# zkOk.sh uses the ruok ZooKeeper four letter work to determine if the instance
# is health. The $? variable will be set to 0 if server responds that it is 
# healthy, or 1 if the server fails to respond.

ZK_CLIENT_PORT=${ZK_CLIENT_PORT:-2181}
OK=$(echo ruok | nc 127.0.0.1 $ZK_CLIENT_PORT)
if [ "$OK" == "imok" ]; then
	exit 0
else
	exit 1
fi