Checkmk

Next generation monitoring.

Software

To get all the dependencies a small helper program is installed.

apt-get install gdebi

Download the checkmk package from the checkmk download page

wget https://download.checkmk.com/checkmk/2.0.0/check-mk-raw-2.0.0_0.buster_amd64.deb
gdebi check-mk-raw-2.0.0_0.buster_amd64.deb

Create a site and start it

omd create monitor
omd start monitor

Install the agent on the system that should be monitored. Let xinetd handle it.

apt-get install xinetd
wget http://checkmk/monitor/check_mk/agents/check-mk-agent_2.0.0-1_all.deb
dpkg -i check-mk-agent_2.0.0-1_all.deb

Download the APT plugin from the server and place it in /usr/lib/check_mk_agent/plugins. Make sure it is executeable.

chmod 755 /usr/lib/check_mk_agent/plugins/mk_apt

Copy the mk_mysql plugin into /usr/lib/check_mk_agent/plugins/ and make it executeable

cd http://checkmk/monitor/check_mk/agents/plugins/mk_mysql
http://checkmk/monitor/check_mk/agents/plugins/mk_mysql
chmod 755 mk_mysql

Create the file /etc/check_mk/mysql.cfg and configure a user for mariadb authentication

[client]
user=checkmk
password=checkmkpassword

opkg install curl
curl http://checkmk/monitor/check_mk/agents/check_mk_agent.openwrt > /usr/bin/check_mk_agent
chmod +x /usr/bin/check_mk_agent

Create ssh keys for the checkmk user, and copy the public key to your openwrt device and place it in /etc/dropbear/authorized_keys

su - monitor
ssh-keygen -t rsa
scp /omd/sites/monitor/.ssh/id_rsa.pub root@192.168.1.13:/etc/dropbear/authorized_keys

Checkmk maintains a DNS cache. If a host changes its IP-address, checkmk will not know this. The solution is to update the DNS cache.

su - monitor
/opt/omd/versions/2.0.0p1.cre/bin/check_mk --update-dns-cache

Another option is to go to Setup -> General -> Global settings -> Execution of checks -> Use DNS lookup cache and disable that feature.