Configuration Syntax

All configuration files have identical syntax. This allows for templating and overriding based on those templates. The templating is allowed by follwing a specific processing order with the files.

The primary config.ini file is processed first. After that the *.ini files in the conf.d directory are processed in lexical order. Each subsequent file in this processing chain can override values defined in prior files.

Anatomy of a configuration file

The configuration files for nrdpd are standard INI files. The DEFAULT section is a magical section from which all others inherit. You can use this section to set the defaults so you don’t have to replicate values in other sections (templating).

Example configuration file

[DEFAULT]
timeout = 10
frequency = 60
state = enable
host = webserver.example.com

[config]
servers = https://nagios.example.com/nrdp
token = SuperSecretToken
host = webserver.example.com
cacert = /etc/pki/tls/certs/example.com.CA.crt

[check:test]
command = sh -c "echo 'Warning the sky is falling'; exit 1"

[check:test2]
command = sh -c "echo 'Critical the sky fell'; exit 2"

[check:test3]
state = disable

The only required section is the [config] section. Obviously if you don’t have any checks, nothing will be submitted, so at least one check should be defined.

[DEFAULT]

The [DEFAULT] section is optional. Any option set here will be the default value for all other sections.

Note

Please take note of the host option. If you set that it will be the default in both the [config] section as well as in the individual [check:*] sections.

[config]

The [config] section of the ini file is where the main options for nrdpd are set. The valid options are:

• servers: required List of NRDP endpoints to submit results to. You can

  submit results to multiple servers. The servers are separated with whitespace.

• token: required The NRDP authentication token. This is necessary for

  sending results in to the service.

• host: optional This is the name of the host in nagios. By default

  the library will populate this with the short name.

  For instance if your full hostname is webserver.example.com the library will poulate this with webserver. If you populate the host option in the [DEFAULT] section and you need to revert to the short name you can either explicitly use the short name or just set host to a blank value.

  [DEFAULT]
  host = webserver.example.com
  
  [config]
  ; Default to what the library thinks
  host =
  ; Override [DEFAULT] with the short name
  host = webserver
  

• cacert: optional If your nrdp endpoint is available via https and

  you don’t have a public cert you may have to pass in the path to a valid x509 CA certificate in PEM format.

[check:SERVICE]

The [check:SERVICE NAME] sections describe the individual service checks to run on the host. The SERVICE NAME aspect needs to be exactly what is defined in the nagios configuration file under the service -> name option.

Example nagios definition matching

define service {
    name        SERVICE NAME
    .....
}

Below is a full configuration example for a service check in defined for nrdpd.

[check:Load Average]
timeout = 10
frequency = 60
state = enable
host = irrelevant.example.com
command = /usr/lib64/nagios/plugins/check_load -w 15,10,5 -c 30,25,20

• timeout: optional If the check does not complete within timeout

  seconds report the check as CRITICAL to Nagios. The type for this value is float. So anything that can reasonably be converted to a float is valid.

  The default value is 10.0 and the minimum value is 1.0.

• frequency: optional Define how frequent to execute the check. The

  internal algorithm for running this attempts to define this as start time to start time. The only deviation to this will be if a previous execution time extends past the next scheduled start time. In this case you will experience an offset change to the schedule.

  The default value is 60.0 and the minimum value is 10.0.

• state: optional Determine the state of the check. This is really only

  useful if you are planning on doing templates. The valid values for this option are:

  • enable: default Enable the check to run as described.

  • disable: Do not run the check at all.

  • fake: Send fake successful results to the nagios server. This

    option is so that you can build a generic template for disk checks and then for the one oddball host in a class that doesn’t have the specified disk, you can send in happy fake results.

• host: optional This value is used in variable substitution within the

  command. Any use of $host or ${host} within the command will be substituted with this value.

  No validation of this value is done. So anything you put in here can be used generically as a variable anywhere on the command line of the command.

• command: required The nagios plugin to execute.

  Variable substitution can be done here. Any value that matches $variable or ${variable} will attempt to substitue the corresponding values in. This feature is primarily of use to people using the libnrdpd library instead of nrdpd. It allows you to customize things to a great extent. If no corresponding variable is found then the literal $variable or ${variable} will be in the command.

Deployment Recommendations

The primary recommended deployment consists of a config.ini file with just the [DEFAULT] and [config] sections in them. Then deploy your generic check template as say conf.d/00-linux-checks.ini, server class specific checks in conf.d/50-apache-checks.ini and finally any machine specific overrides or manual checks in conf.d/99-local.ini.