Running local scripts

[rubin.j (Rubin Jacob)]

Hi,

I’m trying to get a specific script to run on a monitored host. All the other usual checks are working, but this script is not returning what I want to see. On the host, the scripts run as expected:

/usr/lib/check_mk_agent/local/check_node_sync.sh
OK - Node is in sync

The check_mk_agent also picks it up:

sudo check_mk_agent | grep -A 10 ‘^<<<local’
<<local:sep(0)>>
OK - Node is in sync

But on the checkmk server, all I see is this:

Can someone please guide me in the right direction to have this sorted? Thank you!

Regards,
Rubin

[kdeutsch (Karl Deutsch)]

Hi @rubin.j,
the output format does not seem to be quite correct. You must output 4 columns:

Status (0-3) Servicename Performancedata Plugin output
0 YourService - Node is in sync

0 = OK, 1 = WARN, 2 = CRIT

Karl

[rubin.j (Rubin Jacob)]

Hi Karl,

Thanks for your quick reply! So here’s a part of the script I’m running:

BLOCK_DIFF=$(($LATEST_BLOCK_HEIGHT - $LOCAL_BLOCK_HEIGHT))
THRESHOLD=10
if [ “$BLOCK_DIFF” -gt “$THRESHOLD” ]; then
echo “CRITICAL - Node is out of sync by $BLOCK_DIFF blocks”
exit 2
elif [ “$BLOCK_DIFF” -gt 0 ]; then
echo “WARNING - Node is out of sync by $BLOCK_DIFF blocks”
exit 1
else
echo “OK - Node is in sync”
exit 0
fi

How would you recommend I modify the output to be in an acceptable format for CheckMK?

Thanks!

Regards,
Rubin

[r.sander (Robert Sander)]

Have a look at Local checks, it explains everything.

What you seem to have is a classical Nagios plugin with its exit codes. These can be called by the Checkmk agent via the MRPE mechanism, explained here: Monitoring Linux - The new agent for Linux in detail

[rubin.j (Rubin Jacob)]

Hi,

Thanks for your reply. I’m not using Nagios at all. I just want CheckMK to pick up the values. I referred to the Local checks document and this is what my script looks like now:

if [ “$BLOCK_DIFF” -gt “$THRESHOLD” ]; then
echo “2 "Blockchain" - Node is out of sync by $BLOCK_DIFF blocks”
exit 2
elif [ “$BLOCK_DIFF” -gt 0 ]; then
echo “1 "Blockchain" - Node is out of sync by $BLOCK_DIFF blocks”
exit 1
else
echo “0 "Blockchain" - Node is in sync”
exit 0
fi

Here’s what the output looks like:

0 “Blockchain” - Node is in sync

sudo check_mk_agent | grep -A 10 ‘^<<<local’
<<local:sep(0)>>
0 “Blockchain” - Node is in sync

But now, it comes up “Unknown” on the server:

Any ideas?

[rubin.j (Rubin Jacob)]

The backward slash isn’t showing up on this post. But it’s definitely in my script:

Any help, please?

[Dirk]

You must make a service discovery for that host. Because of your old check checkmk thought there was a check named - (just a minus/dash sign), but the actual name is Blockchain.

Also, let your script always do an exit 0, even in the WARN/CRIT cases. Any other value cause problems when the script runs asynchronously (say, every five minutes only or so). Exit values != 0 are used only if the script itself could not run properly (missing permissions or something like that).

Besides that, your local check looks okay to me.

[rubin.j (Rubin Jacob)]

That saved the day! I’ve also changed the exit codes as you suggested. Thank you very much, sir!