mrlesmithjr · September 19, 2020 09:30
diff --git a/haproxy-mysqlchk b/haproxy-mysqlchk
 #!/bin/bash
 # This is for Ubuntu
 apt-get install xinetd

 (
 cat << 'EOF'
 # default: on
 # description: mysqlchk
 service mysqlchk
 {
        flags           = REUSE
        socket_type     = stream
        port            = 9200
        wait            = no
        user            = nobody
        server          = /usr/local/bin/mysqlchk.sh
        log_on_failure  += USERID
        disable         = no
 #        only_from       = 0.0.0.0/0
 # recommended to put the IPs that need
 # to connect exclusively (security purposes)
        per_source      = UNLIMITED
 # Recently added (May 20, 2010)
 # Prevents the system from complaining
 # about having too many connections open from
 # the same IP. More info:
 # http://www.linuxfocus.org/English/November2000/article175.shtml
 }
 EOF
 ) | tee /etc/xinetd.d/mysqlchk


 /usr/sbin/update-rc.d xinetd defaults
 echo "mysqlchk 9200/tcp" >> /etc/services

 #nano usr/local/bin/mysqlchk.sh
 (
 cat << 'EOF'
 #!/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
 #

 MYSQL_HOST="127.0.0.1"
 MYSQL_PORT="3306"
 MYSQL_USERNAME="cmon"
 MYSQL_PASSWORD="cmon"
 MYSQL_OPTS="-N -q -A"
 TMP_FILE="/dev/shm/mysqlchk.$$.out"
 ERR_FILE="/dev/shm/mysqlchk.$$.err"
 FORCE_FAIL="/dev/shm/proxyoff"
 MYSQL_BIN="/usr/bin/mysql"
 CHECK_QUERY="show global status where variable_name='wsrep_local_state'"
 preflight_check()
 {
    for I in "$TMP_FILE" "$ERR_FILE"; do
        if [ -f "$I" ]; then
            if [ ! -w $I ]; then
                echo -e "HTTP/1.1 503 Service Unavailable\r\n"
                echo -e "Content-Type: Content-Type: text/plain\r\n"
                echo -e "\r\n"
                echo -e "Cannot write to $I\r\n"
                echo -e "\r\n"
                exit 1
            fi
        fi
    done
 }
 return_ok()
 {
    echo -e "HTTP/1.1 200 OK\r\n"
    echo -e "Content-Type: text/html\r\n"
    echo -e "Content-Length: 43\r\n"
    echo -e "\r\n"
    echo -e "<html><body>MySQL is running.</body></html>\r\n"
    echo -e "\r\n"
    rm $ERR_FILE $TMP_FILE
    exit 0
 }
 return_fail()
 {
    echo -e "HTTP/1.1 503 Service Unavailable\r\n"
    echo -e "Content-Type: text/html\r\n"
    echo -e "Content-Length: 42\r\n"
    echo -e "\r\n"
    echo -e "<html><body>MySQL is *down*.</body></html>\r\n"
    sed -e 's/\n$/\r\n/' $ERR_FILE
    echo -e "\r\n"
    rm $ERR_FILE $TMP_FILE
    exit 1
 }
 preflight_check
 if [ -f "$FORCE_FAIL" ]; then
        echo "$FORCE_FAIL found" > $ERR_FILE
        return_fail;
 fi
 $MYSQL_BIN $MYSQL_OPTS --host=$MYSQL_HOST --port=$MYSQL_PORT --user=$MYSQL_USERNAME --password=$MYSQL_PASSWORD -e "$CHECK_QUERY" > $TMP_FILE 2> $ERR_FILE
 if [ $? -ne 0 ]; then
        return_fail;
 fi
 status=`cat  $TMP_FILE | awk '{print $2;}'`

 if [ $status -ne 4 ]; then
   return_fail;
 fi

 return_ok;
 EOF
 ) | tee /usr/local/bin/mysqlchk.sh

 chmod 777 /usr/local/bin/mysqlchk.sh
 /etc/init.d/xinetd restart
	#!/bin/bash
	# This is for Ubuntu
	apt-get install xinetd

	(
	cat << 'EOF'
	# default: on
	# description: mysqlchk
	service mysqlchk
	{
	flags = REUSE
	socket_type = stream
	port = 9200
	wait = no
	user = nobody
	server = /usr/local/bin/mysqlchk.sh
	log_on_failure += USERID
	disable = no
	# only_from = 0.0.0.0/0
	# recommended to put the IPs that need
	# to connect exclusively (security purposes)
	per_source = UNLIMITED
	# Recently added (May 20, 2010)
	# Prevents the system from complaining
	# about having too many connections open from
	# the same IP. More info:
	# http://www.linuxfocus.org/English/November2000/article175.shtml
	}
	EOF
	) \| tee /etc/xinetd.d/mysqlchk


	/usr/sbin/update-rc.d xinetd defaults
	echo "mysqlchk 9200/tcp" >> /etc/services

	#nano usr/local/bin/mysqlchk.sh
	(
	cat << 'EOF'
	#!/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
	#

	MYSQL_HOST="127.0.0.1"
	MYSQL_PORT="3306"
	MYSQL_USERNAME="cmon"
	MYSQL_PASSWORD="cmon"
	MYSQL_OPTS="-N -q -A"
	TMP_FILE="/dev/shm/mysqlchk.$$.out"
	ERR_FILE="/dev/shm/mysqlchk.$$.err"
	FORCE_FAIL="/dev/shm/proxyoff"
	MYSQL_BIN="/usr/bin/mysql"
	CHECK_QUERY="show global status where variable_name='wsrep_local_state'"
	preflight_check()
	{
	for I in "$TMP_FILE" "$ERR_FILE"; do
	if [ -f "$I" ]; then
	if [ ! -w $I ]; then
	echo -e "HTTP/1.1 503 Service Unavailable\r\n"
	echo -e "Content-Type: Content-Type: text/plain\r\n"
	echo -e "\r\n"
	echo -e "Cannot write to $I\r\n"
	echo -e "\r\n"
	exit 1
	fi
	fi
	done
	}
	return_ok()
	{
	echo -e "HTTP/1.1 200 OK\r\n"
	echo -e "Content-Type: text/html\r\n"
	echo -e "Content-Length: 43\r\n"
	echo -e "\r\n"
	echo -e "<html><body>MySQL is running.</body></html>\r\n"
	echo -e "\r\n"
	rm $ERR_FILE $TMP_FILE
	exit 0
	}
	return_fail()
	{
	echo -e "HTTP/1.1 503 Service Unavailable\r\n"
	echo -e "Content-Type: text/html\r\n"
	echo -e "Content-Length: 42\r\n"
	echo -e "\r\n"
	echo -e "<html><body>MySQL is down.</body></html>\r\n"
	sed -e 's/\n$/\r\n/' $ERR_FILE
	echo -e "\r\n"
	rm $ERR_FILE $TMP_FILE
	exit 1
	}
	preflight_check
	if [ -f "$FORCE_FAIL" ]; then
	echo "$FORCE_FAIL found" > $ERR_FILE
	return_fail;
	fi
	$MYSQL_BIN $MYSQL_OPTS --host=$MYSQL_HOST --port=$MYSQL_PORT --user=$MYSQL_USERNAME --password=$MYSQL_PASSWORD -e "$CHECK_QUERY" > $TMP_FILE 2> $ERR_FILE
	if [ $? -ne 0 ]; then
	return_fail;
	fi
	status=`cat $TMP_FILE \| awk '{print $2;}'`

	if [ $status -ne 4 ]; then
	return_fail;
	fi

	return_ok;
	EOF
	) \| tee /usr/local/bin/mysqlchk.sh

	chmod 777 /usr/local/bin/mysqlchk.sh
	/etc/init.d/xinetd restart