# Restart Services Automatically

I have been working on a script that automatically checks on the state of 2 services that I require to be running 24/7 on a server that I manage.

The script works as I need, but I would really like to optimize it if possible. Specifically, I find that I want a way to reduce the need to type the command:

$(ps -ef | grep -v grep | grep zabbix_agentd | wc -l)  and $(ps -ef | grep -v grep | grep zabbix_server | wc -l)


Any other feedback is greatly appreciated, I am new to bash scripting and trying to find the best way to get this to be as optimal as possible!

#!/bin/bash
zabbix_server="service zabbix-server"
zabbix_agent="service zabbix-agent"
logfile=/etc/scripts/zabbix/zabbix_auto_restart.log
zabbix_server_running=0
zabbix_agent_running=0

check_zabbix_agentd (){
if (( $(ps -ef | grep -v grep | grep zabbix_agentd | wc -l) <= 0 )) then$zabbix_agent start
echo date "$zabbix_agent was stopped... Restarting" >>$logfile
echo "************************************************" >> $logfile #Send email to notify that the script ran echo "$(date) $zabbix_agent was restarted from zabbix_restart.sh" | mutt -s "Zabbix Auto-restart Script Just Ran" <admin email address> else let zabbix_agent_running=1 fi } check_zabbix_server (){ if (($(ps -ef | grep -v grep | grep zabbix_server | wc -l) <= 0 ))
then
$zabbix_server start echo date "$zabbix_server was stopped... Restarting" >> $logfile echo "************************************************" >>$logfile

#Send email to notify that the script ran
echo "$(date)$zabbix_server was restarted from zabbix_restart.sh" | mutt -s "Zabbix Auto-restart Script Just Ran" <admin email address>

else
let zabbix_server_running=1
fi
}

main_loop (){
until ((zabbix_server_running == 1 && zabbix_agent_running == 1));
do
check_zabbix_agentd
check_zabbix_server
sleep 1.5
done
}

main_loop

• Instead of reinventing the wheel, consider using a standard solution such as Monit. – 200_success Jun 18 '15 at 19:27
• @200_success Zabbix is my monitoring software that does the same thing as Monit. I have this script as a safeguard in-case something were to happen. – Evan Bechtol Jun 18 '15 at 19:45
• Have Zabbix and Monit monitor each other? =) – 200_success Jun 18 '15 at 19:46
• @200_success That would be interesting lol! I did download Monit and am looking at it now – Evan Bechtol Jun 18 '15 at 19:54

As you and I both know, what follows is the answer I posted to your question at Unix and Linux. I'm not sure if this might be considered in bad taste or not - and if so, I'll happily delete it - but at the other site the question was apparently closed as a cross-post in favor of this. And so I thought - maybe it belonged? Anyway, here goes:

What you're really doing wrong is duplicating your effort - basically every hardcoded occurrence of _agent or _server appears to be completely redundant.

For example, if this is being run on a linux system, you can completely drop the grep_...() functions, and consolidate both check_...s into a single entity which might work like:

email(){
mutt -s "Zabbix Auto-restart Script Just Ran" \<user email\>
}
prlog(){
date +"%x %X:%tservice $1${2+%n************************}"
}
chk_run()
while  [ "$#" -gt 0 ] do if ps -C zabbix_"$1"
then   : "$(($1=1))"
else   set zabbix_"$@" service "$1" start || eval >&2 '
prlog   "$1 restart failed." +; exit '"$?"
prlog   "$1 restarted." + >&2 prlog "$1 restarted from $0." |email fi; shift done  The key to that is you would just call chk_run with an argument list each member of which would indicate to it what it should be checking each iteration. loop() until [ "$(($1&&$2))" -eq 1 ]
do    chk_run "$@" sleep 2 done >/dev/null 2>>"$log"
agentd=0 server=0 loop agentd server


POSIXly the only thing that should need altering there is the ps command - because POSIX doesn't specify the -C switch. And so you could just change the if line to look like:

if    ps -eocomm= |
grep -xqF zabbix_"\$1"


Aside from mutt, service, and the ps optimization, it should all be standard command language. At least one advantage to that is the #!/bin/bash hash-bang is completely unnecessary - there is no anchor here to some shell-specific extension, and so it should work pretty much exactly the same in all shells which strive for POSIX-compliance. That means that #!/bin/dash is a very simple optimization in this case.