Support forum for Nagios Core, Nagios Plugins, NCPA, NRPE, NSCA, NDOUtils and more. Engage with the community of users including those using the open source solutions.
On my remote system I am using the "check_init_service" script plugin to allow Nagios to capture the status of a service. I had to modify the script a bit to work within RHEL7 since it uses systemctl for starting services. Problem is now the nagios server is getting the data back and posting into the UI (see image) but it does not ever change the status, it stays green and 'OK' even if the service is down. I'd like this to change status if the service is down or it cant be checked for some reason. Here is the original script:
#!/bin/sh
PROGNAME=`basename $0`
print_usage() {
echo "Usage: $PROGNAME"
}
print_help() {
echo ""
print_usage
echo ""
echo "This plugin checks the status of services normally started by the init process."
echo ""
support
exit 0
}
case "$1" in
--help)
print_help
exit 0
;;
-h)
print_help
exit 0
;;
*)
if [ $# -eq 1 ]; then
/sbin/service $1 status
ret=$?
case "$ret" in
0)
exit $ret
;;
*)
exit 2
;;
esac
else
echo "ERROR: No service name specified on command line"
exit 3
fi
;;
esac
if [ $# -eq 1 ]; then
/bin/systemctl status $1 | awk 'NR==3'
ret=$?
case "$ret" in
So basically changed the /sbin/service line to use /bin/systemctl and only print out the 3rd line. The output shows up in the Nagios UI as seen in the image. And this is where the functionality pretty much stops. I need a way for the server to distinguish between states and update status appropriately. If the service is down I need a "Critical/Red" status and if the service cant be checked I need an "unknown/amber" status, etc...How can I do this?
UPDATE - It appears that Nagios WILL respond appropriately if the check fails altogether. I just re-enabled SELinux and now the Nagios server goes "Crtitical/Red" with a socket timeout. So I would suspect anything that causes Nagios not to get any data would trip this alarm. So the more specific problem/question is if Nagios does get data, but its the wrong data, as in my case, a service that reports down, how do I get Nagios to go "Critical/Red" in that case too?
You're going to want to add an if statement to your script. What is happening is the fact that your awk was successful is making exit with a code of 0, which Nagios things is fine and dandy.
You'll want to do something along the lines of if NR=3 exit 3 to make it exit in a way that Nagios will see it as critical. Make sense?
hsmith wrote:You're going to want to add an if statement to your script. What is happening is the fact that your awk was successful is making exit with a code of 0, which Nagios things is fine and dandy.
You'll want to do something along the lines of if NR=3 exit 3 to make it exit in a way that Nagios will see it as critical. Make sense?
Not the best at scripting But maybe you can help show me what the code would look like. What my "awk 'NR==3' does is only print out the 3rd line of stdout. The typical output is something like this:
I don't need all that I just want that 3rd line. And the 3rd line will always be there it will just say something different if the service is stopped. Like this:
Disregard that I changed it in the wrong place I'm pretty sure. You are saying I need something that can tell when systemctl exits with any other code than 0 corerct?
Correct. I'm not a bash scripting expert myself, but I can try to whip a quick example up for you if you'd like. I wrote a really horrible Nagios Plugin in bash that uses a bunch of if statements.
Ok, I would appreciate that. Just for the record, if you systemctl a service that you know is dead, you will still get an exit code of 0, and a success.
But maybe you can help show me what the code would look like. What my "awk 'NR==3' does is only print out the 3rd line of stdout. The typical output is something like this: