#!/bin/bash # # This script checks if a mysql server is healthy running on localhost. It will # return: # # "HTTP/1.x 200 OK\r" (if mysql is running smoothly) # # - OR - # # "HTTP/1.x 500 Internal Server Error\r" (else) # # The purpose of this script is make haproxy capable of monitoring mysql properly # # Author: Unai Rodriguez # # It is recommended that a low-privileged-mysql user is created to be used by # this script. Something like this: # # mysql> GRANT SELECT on mysql.* TO 'mysqlchkusr'@'localhost' \ # -> IDENTIFIED BY '257retfg2uysg218' WITH GRANT OPTION; # mysql> flush privileges; # # Script modified by Alex Williams - August 4, 2009 # - removed the need to write to a tmp file, instead store results in memory MYSQL_HOST="172.16.0.60" MYSQL_PORT="3306" MYSQL_USERNAME="replication_user" MYSQL_PASSWORD="replication_pass" # # We perform a simple query that should return a few results :-p ERROR_MSG=`/usr/bin/mysql --host=$MYSQL_HOST --port=$MYSQL_PORT --user=$MYSQL_USERNAME --password=$MYSQL_PASSWORD -e "show databases;" 2>/dev/null` # # Check the output. If it is not empty then everything is fine and we return # something. Else, we just do not return anything. # if [ "$ERROR_MSG" != "" ] then # mysql is fine, return http 200 /bin/echo -e "HTTP/1.1 200 OK\r\n" /bin/echo -e "Content-Type: Content-Type: text/plain\r\n" /bin/echo -e "\r\n" /bin/echo -e "MySQL is running.\r\n" /bin/echo -e "\r\n" else # mysql is fine, return http 503 /bin/echo -e "HTTP/1.1 503 Service Unavailable\r\n" /bin/echo -e "Content-Type: Content-Type: text/plain\r\n" /bin/echo -e "\r\n" /bin/echo -e "MySQL is *down*.\r\n" /bin/echo -e "\r\n" fi