Examples of Action Scripts for Third-party Applications

This section includes examples of third-party applications using script agents.

Example B-1 shows an action script that fails over the Apache Web server.

Example B-1 Apache Action Script

#!/bin/sh

HTTPDCONFLOCATION=/etc/httpd/conf/httpd.conf
WEBPAGECHECK=http://<MyVIP>:80/icons/apache_pb.gif

case $1 in
'start')
    /usr/sbin/apachectl -k start -f $HTTPDCONFLOCATION
   RET=$?
    ;;
sleep(10)
    ;;
'stop')
    /usr/sbin/apachectl -k stop
   RET=$?
    ;;
'clean')
    /usr/sbin/apachectl -k stop
   RET=$?
    ;;
'check')
    /usr/bin/wget -q --delete-after $WEBPAGECHECK
   RET=$?
    ;;
*)
   RET=0
    ;;
esac
# 0: success; 1 : error
if [ $RET -eq 0 ]; then
exit 0
else
exit 1
fi

Example B-2 shows the xclock script, which is a simple action script using xclock available as a default binary on all Linux and UNIX platforms.

Example B-2 xclock Action Script

#!/bin/bash
# start/stop/check script for xclock example
# To test this change BIN_DIR to the directory where xclock is based
# and set the DISPLAY variable to a server within your network.

BIN_DIR=/usr/X11R6/bin
LOG_DIR=/tmp
BIN_NAME=xclock
DISPLAY=yourhost.domain.com:0.0
export DISPLAY
exit_code=0

if [ ! -d $BIN_DIR ]
then
        echo "start failed"
        exit 2
fi

PID1=`ps -ef | grep $BIN_NAME | grep -v grep | grep -v xclock_app | awk '{ print $2 }'`
case $1 in
'start')
        if [ "$PID1" != "" ]
        then
           status_p1="running"
        else
           if [ -x $BIN_DIR/$BIN_NAME ]
           then
             umask 002
             ${BIN_DIR}/${BIN_NAME} & 2>${LOG_DIR}/${BIN_NAME}.log
             status_p1="started"
           else
             echo `basename $0`": $BIN_NAME: Executable not found"
             exit_code=1
           fi
        fi

         echo "$BIN_NAME: $status_p1"
         exit $exit_code
        ;;

'stop')
        if [ "${PID1}" != "" ]
        then
           kill -9 ${PID1} && echo "$BIN_NAME daemon killed"
        else
           echo "$BIN_NAME: no running Process!"
        fi
        exit $exit_code
        ;;
'check')
        if [ "$PID1" != "" ]
        then
           echo "running"
           exit 0
        else
           echo "not running"
           exit 1
        fi
        ;;*)
        echo "Usage: "`basename $0`" {start|stop|check}"
        ;;
esac

Example B-3 shows an example of a shell script for an agent to monitor a file. When the agent is started, it creates the file (which is specified through an attribute) and when it is stopped, it deletes the file. The CHECK action consists of only checking whether the file exists. The variables with the _CRS_ prefix are attribute values that are provided to the script in its environment.

Example B-3 Action Script Example

#!/bin/sh
TOUCH=/bin/touch
RM=/bin/rm
PATH_NAME=/tmp/$_CRS_NAME

#
# These messages go into the CRSD agent log file.
echo " *******   `date` ********** "
echo "Action script '$_CRS_ACTION_SCRIPT' for resource[$_CRS_NAME] called for action $1"
#

case "$1" in
  'start')
     echo "START entry point has been called.."
     echo "Creating the file: $PATH_NAME"
     $TOUCH $PATH_NAME
     exit 0
     ;;

  'stop')
     echo "STOP entry point has been called.." 
     echo "Deleting the file: $PATH_NAME"
     $RM $PATH_NAME
     exit 0
     ;;

  'check')
    echo "CHECK entry point has been called.."
    if [ -e $PATH_NAME ]; then
        echo "Check -- SUCCESS"
        exit 0
    else
        echo "Check -- FAILED"
        exit 1
    fi
    ;;

  'clean')
     echo "CLEAN entry point has been called.."
     echo "Deleting the file: $PATH_NAME"
     $RM -f $PATH_NAME
     exit 0
     ;;

esac