A quick foreword, I am not a native Linux SA. If there are corrections to terminology needed or if I have mislabeled something, please, let me know so I can update this page. It took me quite a while to figure out how to allow things to work properly without having to disable SELinux. Thank you!
Beginning from a fresh installation of Nagios Core 4 from Part 1.
Note: Any time you modify a Nagios configuration file, you can restart that Nagios service with command below to see if that step is where something broke.
service nagios restart
Now that that has been established, we’ll temporarily enable Root SSH Access by editing the SSH config file.
vi /etc/ssh/sshd_config
Press the I key to begin editing. Note: for the rest of this document, if edits are required, you will likely need to remember this.
Remove the # from before PermitRootLogin Yes.
#LoginGraceTime 2m
PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10
Next, you’ll write quite. Note: to do this you wil need to ress the Escape key and then type “:wq!” without the quotes to save and exit. (As above with the I key, you will need to remember this.)
:wq!
Restart SSH.
service sshd restart
Open Putty or your favorite SSH method and connect to the device and login as root. If you’re using DHCP, you may need to run the command below to get the IP Address.
ip addr show
Now, to start, we’ll install dependencies.
yum install gd gd-devel php-gd rrdtool rrdtool-perl ruby xorg-x11-fonts-Type1 -y
4. Download or SFTP necessary file, the version I successfully used is listed below.
pnp4nagios-0.6.26.tar.gz
Now, we’ll extract and install PNP4Nagios.
tar zxfv pnp4nagios-0.6.26.tar.gz
cd pnp4nagios-0.6.26
./configure
make all
make fullinstall
make install-init
Now we’ll prep and restart the web service.
chkconfig --add npcd && chkconfig --level 35 npcd on
systemctl reload httpd.service
Browse to the PNP4Nagios web page and make sure it passed the checks.
https://serverip/pnp4nagios/
Now, we’ll rename the file mentioned on the web page if all checks were passed.
mv /usr/local/pnp4nagios/share/install.php /usr/local/pnp4nagios/share/install.php.ORI
Now, we’re going to need to modify the Nagios configuration files.
vi /usr/local/nagios/etc/nagios.cfg
Press the I key to begin editing and update each item as seen below.
host_perfdata_command=process-host-perfdata
service_perfdata_command=process-service-perfdata
process_performance_data=1
enable_environment_macros=1
service_perfdata_file=/usr/local/pnp4nagios/var/service-perfdata
service_perfdata_file_template=DATATYPE::SERVICEPERFDATA\tTIMET::$TIMET$\tHOSTNAME::$HOSTNAME$\tSERVICEDESC::$SERVICEDESC$\tSERVICEPERFDATA::$SERVICEPERFDATA$\tSERVICECHECKCOMMAND::$SERVICECHECKCOMMAND$\tHOSTSTATE::$HOSTSTATE$\tHOSTSTATETYPE::$HOSTSTATETYPE$\tSERVICESTATE::$SERVICESTATE$\tSERVICESTATETYPE::$SERVICESTATETYPE$
service_perfdata_file_mode=a
service_perfdata_file_processing_interval=15
service_perfdata_file_processing_command=process-service-perfdata-file
host_perfdata_file=/usr/local/pnp4nagios/var/host-perfdata
host_perfdata_file_template=DATATYPE::HOSTPERFDATA\tTIMET::$TIMET$\tHOSTNAME::$HOSTNAME$\tHOSTPERFDATA::$HOSTPERFDATA$\tHOSTCHECKCOMMAND::$HOSTCHECKCOMMAND$\tHOSTSTATE::$HOSTSTATE$\tHOSTSTATETYPE::$HOSTSTATETYPE$
host_perfdata_file_mode=a
host_perfdata_file_processing_interval=15
host_perfdata_file_processing_command=process-host-perfdata-file
Next, you’ll write quite. Press the Escape key and then type “:wq!” without the quotes. (You may want to restart the Nagios service to see if you broke anything.)
:wq!
Now, we’ll need to append the commands configuration file for Bulk with NPCD Mode.
vi /usr/local/nagios/etc/objects/commands.cfg
Press the I key to begin editing and add this to the bottom.
#
# Bulk with NPCD mode
#
define command {
command_name process-service-perfdata-file
command_line /bin/mv /usr/local/pnp4nagios/var/service-perfdata /usr/local/pnp4nagios/var/spool/service-perfdata.$TIMET$
}
define command {
command_name process-host-perfdata-file
command_line /bin/mv /usr/local/pnp4nagios/var/host-perfdata /usr/local/pnp4nagios/var/spool/host-perfdata.$TIMET$
}
Press the Escape key and then type “:wq!” without the quotes to save and exit. (You may want to restart the Nagios service to see if you broke anything.)
:wq!
Now, we’ll need to append the templates configuration file. These will be the link identifiers for future monitoring. (Adds graph icons next to either the host or service depending on how it’s implemented later in this documentation.)
vi /usr/local/nagios/etc/objects/templates.cfg
These new host and service objects need to be appended to this configuration file. (Press the I key to begin editing.)
define host {
name host-pnp
action_url /pnp4nagios/index.php/graph?host=$HOSTNAME$&srv=_HOST_' class='tips' rel='/pnp4nagios/index.php/popup?host=$HOSTNAME$&srv=_HOST_
register 0
}
define service {
name srv-pnp
action_url /pnp4nagios/index.php/graph?host=$HOSTNAME$&srv=$SERVICEDESC$' class='tips' rel='/pnp4nagios/index.php/popup?host=$HOSTNAME$&srv=$SERVICEDESC$
register 0
}
Press the Escape key and then type “:wq!” without the quotes to save and exit. (You may want to restart the Nagios service to see if you broke anything.)
:wq!
Option 1: Configure all hosts and/or services to be monitored. (Skip to Option 2 for individual host or server configuration.)
a. Configuration of All Hosts Example:
For implementing this, we’ll need to edit the core templates configuration file.
vi /usr/local/nagios/etc/objects/templates.cfg
You will need to make sure that under the “generic-host” host definition template, you add the “use host-pnp” line as seen below.
define host{
name generic-host ; The name of this host template
use host-pnp
notifications_enabled 1 ; Host notifications are enabled
event_handler_enabled 1 ; Host event handler is enabled
flap_detection_enabled 1 ; Flap detection is enabled
process_perf_data 1 ; Process performance data
retain_status_information 1 ; Retain status information across program restarts
retain_nonstatus_information 1 ; Retain non-status information across program restarts
notification_period 24x7 ; Send host notifications at any time
register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL HOST, JUST A TEMPLATE!
}
Now, you’ll press Escape, followed by “:wq!” to save and quit vi. (You may want to restart the Nagios service to see if you broke anything.)
:wq!
For any update to a configuration file to take effect, you will need to restart the Nagios service.
service nagios restart
b. Configuration of All Services Example:
For implementing this, we’ll need to edit the core templates configuration file.
vi /usr/local/nagios/etc/objects/templates.cfg
You will need to make sure that under the “generic-service” service definition template, you add the “use srv-pnp” line as seen below.
define service{
name generic-service ; The 'name' of this service template
use srv-pnp ; <----
active_checks_enabled 1 ; Active service checks are enabled
passive_checks_enabled 1 ; Passive service checks are enabled/accepted
parallelize_check 1 ; Active service checks should be parallelized (disabling this can lead to major performance problems)
obsess_over_service 1 ; We should obsess over this service (if necessary)
check_freshness 0 ; Default is to NOT check service 'freshness'
notifications_enabled 1 ; Service notifications are enabled
event_handler_enabled 1 ; Service event handler is enabled
flap_detection_enabled 1 ; Flap detection is enabled
process_perf_data 1 ; Process performance data
retain_status_information 1 ; Retain status information across program restarts
retain_nonstatus_information 1 ; Retain non-status information across program restarts
is_volatile 0 ; The service is not volatile
check_period 24x7 ; The service can be checked at any time of the day
max_check_attempts 3 ; Re-check the service up to 3 times in order to determine its final (hard) state
check_interval 2 ; Check the service every 10 minutes under normal conditions
retry_interval 2 ; Re-check the service every two minutes until a hard state can be determined
contact_groups admins ; Notifications get sent out to everyone in the 'admins' group
notification_options w,u,c,r ; Send notifications about warning, unknown, critical, and recovery events
notification_interval 60 ; Re-notify about service problems every hour
notification_period 24x7 ; Notifications can be sent out at any time
register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}
Now, you’ll press Escape, followed by “:wq!” to save and quit vi. (You may want to restart the Nagios service to see if you broke anything.)
:wq!
For any update to a configuration file to take effect, you will need to restart the Nagios service.
service nagios restart
Option 2: Configure a single host and/or single service to be monitored. (Return to Option 1 for monitoring of all hosts or all services.)
a. Individual Host Configuration Example:
For this example, we’ll be using the Nagios localhost monitoring configuration file.
vi /usr/local/nagios/etc/objects/localhost.cfg
You’ll press the I key and append “,host-pnp” after “linux-server” to add host monitoring as seen below.
define host{
use linux-server,host-pnp
host_name localhost
alias localhost
address 127.0.0.1
}
Now, you’ll press Escape, followed by “:wq!” to save and quit vi. (You may want to restart the Nagios service to see if you broke anything.)
:wq!
For any update to a configuration file to take effect, you will need to restart the Nagios service.
service nagios restart
b. Individual Service Configuration Example:
For this example, we’ll be using the Nagios localhost monitoring configuration file.
vi /usr/local/nagios/etc/objects/localhost.cfg
You’ll press the I key and append “,srv-pnp” after “local-service” to add service monitoring as seen below.
define service{
use local-service,srv-pnp
host_name localhost
service_description PING
check_command check_ping!100.0,20%!500.0,60%
}
Now, you’ll press Escape, followed by “:wq!” to save and quit vi. (You may want to restart the Nagios service to see if you broke anything.)
:wq!
For any update to a configuration file to take effect, you will need to restart the Nagios service.
service nagios restart
Next, we’ll copy ssi files then restart NPCD and Nagios.
cd /root/pnp4nagios-0.6.26/
cp contrib/ssi/status-header.ssi /usr/local/nagios/share/ssi/
service npcd restart && service nagios restart
Remove PNP4Nagios Installer
cd ~
rm -rf pnp4nagios-0.6.26*
And now you should be ready to start using PNP4Nagios on your server.
—
If everything worked well, you should return and disable root SSH access.
vi /etc/ssh/sshd_config
Add # before PermitRootLogin yes.
#LoginGraceTime 2m
#PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10
Save and quit vi.
:wq!
Restart SSH.
service sshd restart
—
This post is only one part of a series of Nagios documentation I am be preparing.
Nagios Core 4 on CentOS 7: Part 1 – Installation
Nagios Core 4 on CentOS 7: Part 2 – Installation and Configuration of PNP4Nagios
Nagios Core 4 on CentOS 7: Part 3 – Installation and Configuration of Grafana over HTTPS
Nagios Core 4 on CentOS 7: Part 4 – Installation of V-Shell 2
