Restart Services Automatically

Question

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

• 200_success: Instead of reinventing the wheel, consider using a standard solution such as Monit.
• Evan Bechtol: @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.
• 200_success: Have Zabbix and Monit monitor each other? =)
• Evan Bechtol: @200_success That would be interesting lol! I did download Monit and am looking at it now

Answer 1

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ドル${2+%n************************}"
}
chk_run()
 while [ "$#" -gt 0 ]
 do if ps -C zabbix_"1ドル"
 then : "$((1ドル=1))"
 else set zabbix_"$@"
 service "1ドル" start || eval >&2 '
 prlog "1ドル restart failed." +; exit '"$?"
 prlog "1ドル restarted." + >&2
 prlog "1ドル restarted from 0ドル." |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 [ "$((1ドル&&2ドル))" -eq 1 ]
 do chk_run "$@"
 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ドル"

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.