PNP4Nagios

PNP is an addon to Nagios which analyzes performance data provided by plugins and stores them automatically into RRD-databases. [1]

Basic information

• Official Website: https://docs.pnp4nagios.org/

• License: GNU General Public License v2.0

Tested on (Requirements)

• Nagios Core: Version \(\boldsymbol{\ge}\) 2.x

Dependencies

• RRDTool

• PHP

• Perl

• Perl RRDTool

• PHP-GD

Installation

This taskfile is executed only if the folder /usr/local/pnp4nagios doesn’t exist. This state is registered in the taskfile nagios-plugins-installed.yml, with the module stat.

For more information about these registers read the section Installing Nagios Plugins.

The installation process consists of downloading, uncompressing, configuring and compiling the plugin.

Note

fullinstall option installs the main program, runlevel scripts, config and HTML files.

---
- name: Create Temp Dir
  file:
    path: "{{ temp_dir }}"
    state: directory

- name: Download PNP4Nagios Plugin
  get_url:
    url: "{{ pnp_plugin_url }}"
    dest: "{{ temp_dir }}/{{ pnp_plugin_file }}"

- name: Extract PNP4Nagios Plugins
  unarchive:
    src: "{{ temp_dir }}/{{ pnp_plugin_file }}"
    dest: "{{ temp_dir }}"

- name: Exec configure
  shell: "./configure"
  args:
    chdir: "{{ temp_dir }}/pnp4nagios-0.6.26"

- name: Make all
  make:
    chdir: "{{ temp_dir }}/pnp4nagios-0.6.26"
    target: all

- name: Make Full install
  make:
    chdir: "{{ temp_dir }}/pnp4nagios-0.6.26"
    target: fullinstall

Configuration

PNP4Nagios can be configured in 5 different modes:

• Synchronous

• Bulk

• Bulk with NPCD

• Bulk with NPCD and npcdmod

• Gearman

This procedure will configure PNP4Nagios in Bulk with NPCD mode. Bulk mode reduces the load on the Nagios Server because the data collection and Processing is not executed by a Nagios process but by NPCD.

Nagios Performance C Daemon (NPCD) processes the Performance Data produced by Nagios plugins.

Note

For more information about the different configuration modes, read [2].

Edit the following options in nagios.cfg file:

process_performance_data=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

It’s necessary to redefine the process-service-perfdata-file and process-host-perfdata-file commands:

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-hosts-perfdata-file
             command_line    /bin/mv /usr/local/pnp4nagios/var/host-perfdata /usr/local/pnp4nagios/var/spool/host-perfdata.$TIMET$
}

“Using these commands the file service-perfdata will be moved to /usr/local/pnp4nagios/var/spool/ after the interval specified in service_perfdata_file_processing_interval has passed. The Nagios macro $TIMET$ is appended to the filename to avoid overwriting of old files unintentionally.” [2]

NPCD monitors /usr/local/pnp4nagios/var/spool/ directory and process_perfdata.pl processes these files decoupled from Nagios.

Note

This configuration process is intended to be automated with the task nagios-config.yml. These options should be written previously in the config files present in the ansible role.

After configuring PNP4Nagios, it’s recommended to start NPCD as a daemon, executing:

/usr/local/pnp4nagios/bin/npcd -d -f /usr/local/pnp4nagios/etc/npcd.cfg

The task pnp4nagios-config will enable NPCD in boot time and will synchronize a PHP configuration file needed by PHP-GD, a dependency of PNP4Nagios.

Note

For more information about PHP-GD read php-gd not detected

---
- name: Service NPCD enabled at boot time
  service:
    name: npcd
    enabled: yes
    state: started

- name: Synchronize gd.ini file
  copy:
    src: etc/php.d/gd.ini
    dest: /etc/php.d/gd.ini
  notify: apache_restart

- name: Correct Group and Owner for PNP dirs
  file:
    path: /usr/local/pnp4nagios
    group: nagcmd
    owner: nagios
    recurse: yes

Test PNP4Nagios

1. Perl Script

PNP4Nagios can be tested executing a verification script provided by the official page. The main script options are:

Params	Value
-m <mode>	sync | bulk | bulk+npcd | npcdmod
-c <path>	Location of nagios.cfg
-p <path>	Path to PNP config dir

wget http://verify.pnp4nagios.org/verify_pnp_config
perl verify_pnp_config -m bulk+npcd -c /usr/local/nagios/etc/nagios.cfg -p /usr/local/pnp4nagios/etc/

2. PHP Home Page Check

After installing and configuring PNP4Nagios, the Home webpage http://<host>/pnp4nagios will display a detailed environment test:

If your environment passed all requirements, remove the /usr/local/pnp4nagios/share/install.php file.

Troubleshooting

php-gd not detected

PROBLEM: PHP-GD is installed but is unrecognizable by PHP.

SOLUTION: To create a file in /etc/php.d/ that contains the extension information indicating the path to the gd.so library. Example:

[gd]
extension=/usr/lib64/php/modules/gd.so

Can’t find Nagios Environment

PROBLEM: If PNP4Nagios is configured in Sync mode using Nagios Core 4.x, the following message appears on the web page:

Cant find Nagios Environment. Exiting ....
perfdata directory "/usr/local/pnp4nagios/var/perfdata/" is empty. Please check your Nagios config.

SOLUTION: Apparently, it’s a Nagios 4 bug, where environment data used by pnp4nagios is not provided in sync mode [3]. Bulk mode with NPCD is a better mode for configuring PNP4Nagios.

References

[1]

PNP4Nagios Docs. Retrieved February 8, 2019, from https://docs.pnp4nagios.org/pnp-0.6/start

[2] (1,2)

PNP4Nagios Configuration. Retrieved February 11, 2019, from https://docs.pnp4nagios.org/pnp-0.6/config

[3]

Nagios Support Forum - PNP4nagios: Can’t find Nagios Environment [SOLVED]. Retrieved February 11, 2019, from https://support.nagios.com/forum/viewtopic.php?f=7&t=29953