How To Create Nagios Plugins With Python On CentOS 6 |
||||||||||
This time, we will expand on this idea and create Nagios plugins using Python.Step 1 - Install RPMForge Repository and NRPErpm -ivh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm yum -y install python nagios-nrpe useradd nrpe && chkconfig nrpe on Step 2 - Create your Python ScriptIt would be a good idea to keep your plugins in same directory as other Nagios plugins (/usr/lib64/nagios/plugins/ for example). For our example, we will create a script that checks current disk usage by calling "df" from shell, and throw an alert if it is over 85% used: #!/usr/bin/python import os, sys used_space=os.popen("df -h / | grep -v Filesystem | awk '{print $5}'").readline().strip() if used_space < "85%": print "OK - %s of disk space used." % used_space sys.exit(0) elif used_space == "85%": print "WARNING - %s of disk space used." % used_space sys.exit(1) elif used_space > "85%": print "CRITICAL - %s of disk space used." % used_space sys.exit(2) else: print "UKNOWN - %s of disk space used." % used_space sys.exit(3) We will save this script in /usr/lib64/nagios/plugins/usedspace.py and make it executable: chmod +x /usr/lib64/nagios/plugins/usedspace.py The entire Nagios NRPE plugin boils down to using exit codes to trigger alerts. You introduce your level of logic to the script, and if you want to trigger an alert (whether it is OK, WARNING, CRITICAL, or UNKNOWN) - you specify an exit code. Refer to the following Nagios Exit Codes: Nagios Exit Codes
Step 3 - Add Your Script to NRPE configuration on client hostDelete original/etc/nagios/nrpe.cfgand add the following lines to it: log_facility=daemon pid_file=/var/run/nrpe/nrpe.pid server_port=5666 nrpe_user=nrpe nrpe_group=nrpe allowed_hosts=198.211.117.251 dont_blame_nrpe=1 debug=0 command_timeout=60 connection_timeout=300 include_dir=/etc/nrpe.d/ command[usedspace_python]=/usr/lib64/nagios/plugins/usedspace.py Where 198.211.117.251 is our monitoring server from previous articles. Change these to your own values. Make sure to restart Nagios NRPE service: service nrpe restart Step 4 - Add Your New Command to Nagios Checks on Nagios Monitoring ServerDefine new command in/etc/nagios/objects/commands.cfg define command{ command_name usedspace_python command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c usedspace_python } As you can see, it uses NRPE to make TCP connections to port 5666 and run command 'usedspace_python', which we defined in /etc/nagios/nrpe.cfg on that remote host. Add this check to your Nagios configuration file for client server. For our example, we will monitor a server called MyCentOS and edit /etc/nagios/servers/MyCentOS.cfg define service { use generic-service host_name MyCentOS service_description Custom Disk Checker In Python check_command usedspace_python }Restart Nagios: service nagios restart Verify that the new check is working. And you are all done! |
||||||||||
Posted by: ASPHostServer Administrator - Sat, Jan 4, 2014 at 1:39 AM. This article has been viewed 3311 times. | ||||||||||
Online URL: http://faq.asphosthelpdesk.com/article.php?id=264 |