nagios-config.md

Nagios Configuration

Notification Command Configuration

Nagios needs to be instructed to use nagios-herald for notifications. The main notification program in nagios-herald is called nagios-herald.

To configure Nagios to generate alerts via nagios-herald, update the relevant stanza(s) in commands.cfg. The below example assumes nagios-herald is installed in /usr/local/bin.

# email
define command {
    command_name    notify-host-by-email
    command_line    /usr/local/nagios-herald/bin/nagios-herald --message-type email --formatter=$_HOSTMESSAGE_FORMATTER_NAME$ --nagios-cgi-url=http://nagios.example.com/nagios/cgi-bin/cmd.cgi --reply-to=nagios@example.com
}

# specify the location of custom formatters
define command {
    command_name    notify-service-by-email
    command_line    /usr/local/nagios-herald/bin/nagios-herald --message-type email --formatter=$_SERVICEMESSAGE_FORMATTER_NAME$ --nagios-cgi-url=http://nagios.example.com/nagios/cgi-bin/cmd.cgi --reply-to=nagios@example.com --formatter-dir=/usr/local/nagios-herald-formatters
}

# pager
define command {
    command_name    notify-host-by-pager
    command_line    /usr/local/nagios-herald/bin/nagios-herald --message-type pager --formatter=$_HOSTMESSAGE_FORMATTER_NAME$ --nagios-cgi-url=http://nagios.example.com/nagios/cgi-bin/cmd.cgi --reply-to=nagios@example.com
}

define command {
    command_name    notify-service-by-pager
    command_line    /usr/local/nagios-herald/bin/nagios-herald --message-type pager --formatter=$_SERVICEMESSAGE_FORMATTER_NAME$ --nagios-cgi-url=http://nagios.example.com/nagios/cgi-bin/cmd.cgi --reply-to=nagios@example.com
}

# IRC (optional)
define command {
    command_name    notify-host-by-irc
    command_line    /usr/local/nagios-herald/bin/nagios-herald --message-type irc --formatter=$_HOSTMESSAGE_FORMATTER_NAME$ --nagios-cgi-url=http://nagios.example.com/nagios/cgi-bin/cmd.cgi --reply-to=nagios@example.com
}

define command {
    command_name    notify-service-by-irc
    command_line    /usr/local/nagios-herald/bin/nagios-herald --message-type irc --formatter=$_SERVICEMESSAGE_FORMATTER_NAME$ --nagios-cgi-url=http://nagios.example.com/nagios/cgi-bin/cmd.cgi --reply-to=nagios@example.com
}

NOTE: $_HOSTMESSAGE_FORMATTER_NAME$ and $_SERVICEMESSAGE_FORMATTER_NAME$ are Nagios macros, generated from a custom variable in a relevant service check definition.

You must also add command definitions for any custom message classes that you plan to use. See the messages page for details.

Tracing Errors

If nagios-herald is failing to notify, you can turn up the logging via the --trace option to gather more information, like so:

command_line    /usr/local/nagios-herald/bin/nagios-herald --message-type email --formatter=$_SERVICEMESSAGE_FORMATTER_NAME$ --nagios-cgi-url=http://nagios.example.com/nagios/cgi-bin/cmd.cgi --reply-to=nagios@example.com --trace

Service Configuration

To apply a formatter to a service check, add the _message_formatter_name custom variable in the relevant stanza in services.cfg: The value of the variable is the name of the formatter.

define service {
    hostgroup_name                  web_servers
    service_description             Disk Space
    notification_interval           20
    check_command                   check_nrpe!check_disk
    _message_formatter_name         check_disk            <<<< custom variable
    contact_groups                  ops
}

NOTE: If no formatter is specified, nagios-herald defaults to the base formatter and generates generic content for messages.