Changing JVM options using a shell script

The below script is used to customize a TC sever setenv.sh for multiple TC instances.
The script reads a config file and applys this to the setenv and pushes it to the instace loaction.


[sherif@khofo05 ~ ]$ cat fixSetenv.sh
OLD_IFS=${IFS}
IFS='
'
for INST in `cat tc_nodes |grep -v "^#"`
do 
    USER=`echo ${INST} |cut -d":" -f1`
    TC_INST=`echo ${INST} |cut -d":" -f2|cut -d"@" -f1`
    HOST=`echo ${INST} |cut -d":" -f2| cut -d "_" -f1`
    HTTP_PORT=`echo ${INST} |cut -d "_" -f2|cut -d"@" -f1`
    HOME_DIR=`echo ${INST} |cut -d"@" -f2`
    JVM_PAR=`echo ${INST} |cut -d"@" -f3`
    NEW_JAVA_HOME="JAVA_HOME=${HOME_DIR}/springsource/jdk1.7.0_21"

     OLD_JVM_PAR=`grep "JVM_OPTS=" setenv.sh|tr -d '\n'`
    OLD_JAVA_HOME=`grep "JAVA_HOME=" setenv.sh|tr -d '\n'`
IFS=${OLD_IFS}
#echo "---------------"
echo "working on ${HOST}"
echo "sed -- 's%${OLD_JVM_PAR}%${JVM_PAR}%g' setenv.sh |" >sed_cmd
echo "sed -- 's%${OLD_JAVA_HOME}%${NEW_JAVA_HOME}%g'" >>sed_cmd
echo "creating custome setenv "
bash ./sed_cmd >setenv.sh_${TC_INST}
scp setenv.sh_${TC_INST}  ${USER}@${HOST}:${HOME_DIR}/springsource/vfabric-tc-server-standard-2.9.2.RELEASE/${TC_INST}/bin/setenv.sh
echo "sent to ${TC_INST}
Done"
done
IFS=${OLD_IFS}
[sherif@khofo05 ~ ]$

The instances config file is named tc_nodes.
This file looks like this:

username1:hostname01_8080@/home/dir/of/username1@JVM_OPTS="-server -Xms4096m -Xmx4096m -Xss192k -XX:MaxPermSize=512m -XX:PermSize=256m -XX:ParallelGCThreads=2 -XX:NewSize=256m -XX:MaxNewSize=256m -Xnoclassgc -XX:SurvivorRatio=14 -Xloggc:${HOME}/logs/gc.log"

This is parsed for the parameters used by the script.
I found it more difficult to run the sed commads from within the same script. so to solve this the fixsetenv.sh creates another script and runs it.
this is the sed_cmd script.
this one looks like this:

[sherif@khofo05 ~]$ cat sed_cmd
sed -- 's%JVM_OPTS="-Xmx512M -Xss256K"%JVM_OPTS="-server -Xms4096m -Xmx4096m -Xss192k -XX:MaxPermSize=512m -XX:PermSize=256m -XX:ParallelGCThreads=2 -XX:NewSize=256m -XX:MaxNewSize=256m -Xnoclassgc -XX:SurvivorRatio=14 -Xloggc:${HOME}/logs/gc.log"%g' setenv.sh |
sed -- 's%JAVA_HOME="/homedire1/springsource/jdk1.7.0_21"%JAVA_HOME=/homedire1/springsource/jdk1.7.0_21%g'
[sherif@khofo05 ~]$

The above made it possible to do custom changes based on the config files.
In order to come around parsing the whole JVM_OPTs with the spaces and things like that I had to change the Internal field separator.
This made it possible to accommodate the spaces.


Automation is fun :)