As a developer I need to be able to start my processes in a certain way. One way to do that may be to modify the startup code we've got in our management system, but I found it way more flexible and easy to just replace our binaries with wrapper scripts that starts up our binaries.
Please note that this is something I do when I try to track down a certain bug, and not something I recommend in your production environment.
I've created my own little script that installs the wrapper script:
#! /bin/ksh
cat > /opt/membase/bin/launcher.sh <
#! /bin/ksh
logfile=/tmp/membase.log
binary=\`basename \$0\`
echo pid \$\$ : \$0 \$* >> \${logfile}
exec \${0}.bin "\$@" 2>&1 | awk "{printf(\"%d: %s\n\", $$, \\\$0); }" >> \${logfile}
EOF
chmod a+x /opt/membase/bin/launcher.sh
for f in memcached vbucketmigrator moxi
do
mv /opt/membase/bin/${f}/${f} /opt/membase/bin/${f}/${f}.bin
ln -s ../launcher.sh /opt/membase/bin/${f}/${f}
done
As an extra bonus this redirects all of the output from the processes to
/tmp/membase.log, so that I can just check there for the error text instead of running browse_logs and start decoding the output there.
The above script use the
same wrapper script for all processes, but sometimes I want to add extra options to one of the processes (like enabling verbosity for
vbucketmigrator). All I need to do is just to replace the link with a copy of the file:
root@ubuntu:/opt/membase/bin# rm vbucketmigrator/vbucketmigrator
root@ubuntu:/opt/membase/bin# cp -p launcher.sh vbucketmigrator/vbucketmigrator
and edit the file. Since I'm going to add extra command line options, I'm most likely expecting more output so normally I store the output in its own file as well:
#! /bin/ksh
logfile=/tmp/vbucketmigrator.$$
binary=`basename $0`
echo pid $$ : $0 $* >> ${logfile}
exec ${0}.bin "$@" -vv 2>&1 >> ${logfile}
The next time
vbucketmigrator starts it will dump the message traffic to
/tmp/vbucketmigrator.pid
