Posts By: jonny

SELinux: Create Policy for NRPE Writing

Had a problem with Nagios/NRPE checks that are configured to write a status file as part of their check. The path /var/logstate was the target created the policy below. Andrew (Urban Penguin) Youtube video is an excellent resource. Install selinux utilities: yum install policycoreutils policycoreutils-devel setools-console setroubleshoot The audit log (/var/log/audit/audit.log) was showing the type=AVC… Read more »

Nagios NRPE omreport errors

Nagios check for Dell OpenManage was failing after upgrade to srvadmin 9.2 with: UNKNOWN: Problem running ‘omreport chassis memory’: Error: SMStatus: 700 UNKNOWN: Problem running ‘omreport chassis batteries’: Error! XML Transformation failed UNKNOWN: Problem running ‘omreport chassis pwrmonitoring’: Error: SMStatus: 700 UNKNOWN: Problem running ‘omreport chassis removableflashmedia’: Error: SMStatus: The check command: /usr/lib64/nagios/plugins/check_openmanage -s -b… Read more »

check_mk: Check http service

In the WATO menu choose ‘Check Plugins’ and then ‘Networking checks without an agent’. Find the ‘HTTP/HTTPS connection’ option and then click on ‘Check HTTP service’ beside Parameter rule set: Scroll down to the bottom and click ‘Create rule in folder’ Set the parameters for the check , then save and activate.

check_mk: Check APT updates

On your check_mk install under the WATO menu navigate to ‘Monitoring Agents’ find and click on the link for ‘Check for APT updates (Debian, Ubuntu)’. This is the check plugin to add to the server so copy that code. Copy the contents of that check file to a file named mk_apt file in the /usr/lib/check_mk_agent/local… Read more »

ThingsBoard API: Get telemetry values

I’m using Insomnia for testing and after already getting the auth token I use that in Insomnia as follows: The URL I used for the query was: The word device in there does not need to be changed by the ID field that follows it should be changed to the UUID of your device. You… Read more »

Blink Hard Disk Light on Dell

To blink the light on a hard disk on Dell Server from the command line first get a list of the physical disks so you can check the disk ID: omreport storage pdisk controller=0 then to blink the disk: omconfig storage pdisk action=blink controller=0 pdisk=0:0:2

check_mk: Emails Not Sent

On a CentOS 7 server with postifx already installed and working I found the emails from check_mk / OMD were not being sent. I needed a symlink for sendmail: ln -s /usr/lib/sendmail.postfix /usr/lib/sendmail Test with su – omduserecho “content” | mail -s test-email me@gmail.com

check_mk: monitor that a process exists

WATO > Manual Checks and click on “State and Count of Processes” Add the description, check-type, process name and process matching and set the levels for the number of these processes that are expected:

check_mk: Check for Yum Updates

Visit the page below to download the mkp package: https://checkmk.de/check_mk-exchange-file.php?&file=linux-updates-1.0.mkp Upload the mkp package to your check_mk server then install it : OMD[mysite]:~$ mkp -v install linux-updates-1.0.mkp On the servers to be checked add the check shell script. cd /usr/share/check-mk-agent/local vi mk_linuxupdates.sh The code for the check is within the download but shown here too:… Read more »