Editing NRPE-AND-NRPE-PLUGIN-ON-CLIENT-MACHINE(SANDHAR)

'''STEPS TO CONFIGURE NRPE AND NRPE PLUGIN ON CLIENT MACHINE:-'''


ON CLIENT MACHINE: 

Install libraries for dependencies as it would help in compiling the NRPE packages.


Step 1- install libraries 

# yum install -y gcc glibc glibc-common gd gd-devel make net-snmp openssl-devel 

step 2- user and password 

# useradd nagios 
# passwd nagios 

step 3-extract plugins 

# tar –xvf nagios-plugins-1.5.tar.gz 

step 4- compile and install 
# cd nagios-plugins-1.5 
# ./configure 
# make 
# make install 
step 5-permissions on plugins 

# chown nagios.nagios /usr/local/nagios 
# chown -R nagios.nagios /usr/local/nagios/libexec 
step 6-install xinetd 

#yum install xinetd 

step 7-install nrpe 

tar xzf nrpe-2.15.tar.gz 
# cd nrpe-2.15 
# ./configure 
# make all 
# make install-plugin 
# make install-daemon 
# make install-daemon-config 
#make install-xinetd 

step 8-add nagios monitoring server ip 

#vim /etc/xinetd.d/nrpe 
add only_from = 127.0.0.1  <nagios_ip_address> 
#vim /etc/service 
add nrpe            5666/tcp                 #NRPE 

step 9-restart xinetd 

#/etc/init.d/xinetd restart 

step 10-verify nrpe daemon 

# netstat -at | grep nrpe 

tcp        0      0 *:nrpe                      *:*                         LISTEN 

step 11-To check nrpe daemon is workig properly 

# /usr/local/nagios/libexec/check_nrpe -H localhost 
NRPE v2.15 

step 12- customize nrpe commands and add commands 

# vim /usr/local/nagios/etc/nrpe.cfg 
 command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10 
 command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20 
 command[check_hda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/mapper/vg_mail1-LogVol01 
 command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z 
 command[check_cpu]=/usr/local/nagios/libexec/check_cpu.sh -w 60 -c 70 
 command[check_mem]=/usr/local/nagios/libexec/check_mem_avail -w 10 -c 5 
 command[check_queue]=/usr/local/nagios/libexec/check_postfix_queue -w 200 -c 250 
 command[check_zimbra_lmtp]=/usr/local/nagios/libexec/check_smtp -H localhost -p 7025 -e '220 node.sandhar.in Zimbra LMTP server ready' 
 command[check_smtp]=/usr/local/nagios/libexec/check_smtp -H localhost 

step 13 -run /etc/init.d/xinetd restart 

step 14 – reload nagios on nagios server: 
#/etc/init.d/nagios reload 

step 15 -After then we should call all services from nagios server: 
# /usr/local/nagios/libexec/check_nrpe -H 172.17.16.22 -c check_zimbra_lmtp 
ERROR: could not complete SSL handshake 
# /usr/local/nagios/libexec/check_nrpe -H 172.17.16.22 -c check_smtp 
ERROR: could not complete SSL handshake 

That means we are not able to call services from nagios server to client machine. This is happening because of openssl library missing. For this we need to run nrpe as daemon with non ssl. The command is: 
# /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d -n 
Now in future whenever we will add services of mailserver in sandhar, we need to follow below steps: 

step 16-kill the nrpe running and run nrpe as daemon. 
    # ps -elf | grep nrpe 
 0 S root       747 15083  0  80   0 - 25813 pipe_w 10:59 pts/0    00:00:00 grep nrpe 
 5 S nagios   22682     1  0  80   0 -  9810 poll_s Feb02 ?        00:00:00 /usr/local /nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d -n 

   # kill -9  22682 
   # /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d -n 

step -17 Now test from nagios server. 
# /usr/local/nagios/libexec/check_nrpe -H 172.17.16.22 -c check_zimbra_lmtp 
SMTP OK - 0.001 sec. response time|time=0.000956s;;;0.000000 

# /usr/local/nagios/libexec/check_nrpe -H 172.17.16.22 -c check_smtp 
SMTP OK - 0.002 sec. response time|time=0.002258s;;;0.000000 

# /usr/local/nagios/libexec/check_nrpe -H 172.17.16.22 -c check_cpu 
OK - user: 23.22, nice: 1.11, sys: 2.95, iowait: 0.62, irq: 0.50, softirq: 0.74 idle: 74.33 | 'user'=23.22 'nice'=1.11 'sys'=2.95 'softirq'=0.74 'iowait'=0.62 'irq'=0.50 'idle'=74.33 

# /usr/local/nagios/libexec/check_nrpe -H 172.17.16.22 -c check_queue 
33 mail(s) in queue | mail_queue=33 

step 18- Add host on nagios server of sandhar. 
# vim /usr/local/nagios/etc/objects/linux-box.cfg 
define host{ 
        use                      linux-server 
        host_name               CORP-MAILSERVER 
        alias                   CORP-MAILSERVER 
        address                172.17.16.22 
        hostgroups      Windows Server 
 } 

step 19- Add services on nagios server. 

define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description Current Users 
          notification_options     w,u,c,r 
          check_command       check_nrpe!check_users 
} 


define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description Server Load 
         notification_options     w,u,c,r 
          check_command       check_nrpe!check_load 
} 
define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description Disk Space 
          notification_options     w,u,c,r 
          check_command       check_nrpe!check_hda1 
} 
define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description Zombie process 
           notification_options     w,u,c,r 
          check_command       check_nrpe!check_zombie_procs  
} 
define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description CPU Load 
          notification_options     w,u,c,r 
          check_command       check_nrpe!check_cpu 
} 
define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description Memory Utilization 
          notification_options     w,u,c,r 
          check_command       check_nrpe!check_mem 
} 
define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description Mail Queue 
          notification_options     w,u,c,r 
          check_command       check_nrpe!check_queue 
} 
define service{ use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description Mail Queue 
          notification_options     w,u,c,r 
          check_command       check_nrpe!check_queue  
} 
define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description LMTP 
          notification_options     w,u,c,r 
          check_command       check_nrpe!check_zimbra_lmtp 
} 

define service{ 
          use                 generic-service 
          host_name           CORP-MAILSERVER 
          service_description SMTP 
          notification_options     w,u,c,r 
          check_command       check_smtp 
} 

step 20- verify the nagios.cfg file. 

# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg 
Checking services... 
	Checked 815 services. 
Checking hosts... 
	Checked 108 hosts. 
Checking host groups... 
	Checked 5 host groups. 
Checking service groups... 
	Checked 0 service groups. 
Checking contacts... 
	Checked 16 contacts. 
Checking contact groups... 
	Checked 12 contact groups. 
Checking service escalations... 
	Checked 2962 service escalations. 
Checking service dependencies... 
	Checked 0 service dependencies. 
Checking host escalations... 
	Checked 0 host escalations. 
Checking host dependencies... 
	Checked 0 host dependencies. 
Checking commands... 
	Checked 70 commands. 
Checking time periods... 
	Checked 6 time periods. 
Checking for circular paths between hosts... 
Checking for circular host and service dependencies... 
Checking global event handlers... 
Checking obsessive compulsive processor commands... 
Checking misc settings... 

Total Warnings: 0 
Total Errors:   0 

If we get below error  in the escalation.cfg file that means there is empty services defined for any host. For this we need to check config file. 
ERROR:  could not expand the services defined in ‘service escalation’ config ( /usr/local/nagios/etc/objects/escalation.cfg ) 

First disable the escalation.cfg in nagios.cfg file: 
#cfg_file=/usr/local/nagios/etc/objects/escalation.cfg 
 Second verify the config file nagios.cfg file: 
# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg 
It will show you the warning like this: 
Checking host escalations... 
	Checked 0 host escalations. 
Checking host dependencies... 
	Warning: ‘node1.sandhar.in’ 
Checking commands... 
	Checked 70 commands. 

To resolve this either you define the services for that host or disable that host. And verify the nagios.cfg file. 
If total warnings is 0 and total errors is 0 then reload nagios. 

# /etc/init.d/nagios reload