If you want to monitor a remote host from the Zabbix Agent (so not via a Zabbix Distributed monitoring setup or Zabbix Proxy), you can use the following simple script. This is useful if you have services that are only bound on localhost/127.0.0.1 and thus cannot be checked from the outside.
Custom script for testing local ports
For that, you need a workaround via the Zabbix Agent to check locally if the port is available and accepting connections.
#!/bin/bash # Attempt to open a connection on a particular port (1234) /usr/bin/nc -z 10.0.1.1 1234 > /dev/null # See if it worked if [ $? -eq 0 ]; then # It worked, return value is 0 echo 1 else # Return value is not 0, command failed echo 0 fi
That will need netcat (yum install nc) to test if the connection on that port succeeded. If it doesn’t, it’ll return a 0 value. If it did succeed, it will return 1.
Custom UserParameter in Zabbix Agent
You can then add a custom parameter to call that script and return the values to Zabbix.
UserParameter=custom.monitor_port,/etc/zabbix/externalscripts/custom_check_port_1234.sh
If you want, it’s easily extended to allow the script to be given parameters that can be given via Zabbix.
UserParameter=custom.monitor_port[*],/etc/zabbix/externalscripts/custom_check_port.sh $1
And the script should be something like this.
#!/bin/bash # Attempt to open a connection on a particular port (1234) /usr/bin/nc -z 10.0.1.1 $@ > /dev/null # See if it worked if [ $? -eq 0 ]; then # It worked, return value is 0 echo 1 else # Return value is not 0, command failed echo 0 fi
Now you only have to add that item in Zabbix to retrieve the values.