NAME

Nagios::Monitoring::Plugin::Functions - functions to simplify the creation of Nagios plugins

SYNOPSIS

    # Constants OK, WARNING, CRITICAL, and UNKNOWN exported by default
    use Nagios::Monitoring::Plugin::Functions;

    # nagios_exit( CODE, $message ) - exit with error code CODE,
    # and message "PLUGIN CODE - $message"
    nagios_exit( CRITICAL, $critical_error ) if $critical_error;
    nagios_exit( WARNING, $warning_error )   if $warning_error;
    nagios_exit( OK, $result );

    # nagios_die( $message, [$CODE] ) - just like nagios_exit(),
    # but CODE is optional, defaulting to UNKNOWN
    do_something()
      or nagios_die("do_something() failed horribly");
    do_something_critical()
      or nagios_die("do_something_critical() failed", CRITICAL);

    # check_messages - check a set of message arrays, returning a 
    # CODE and/or a result message
    $code = check_messages(critical => \@crit, warning => \@warn);
    ($code, $message) = check_messages(
      critical => \@crit, warning => \@warn,
      ok => \@ok );

    # get_shortname - return the default short name for this plugin
    #   (as used by nagios_exit/die; not exported by default)
    $shortname = get_shortname();

DESCRIPTION

This module is part of the Nagios::Monitoring::Plugin family, a set of modules for simplifying the creation of Nagios plugins. This module exports convenience functions for the class methods provided by Nagios::Monitoring::Plugin. It is intended for those who prefer a simpler functional interface, and who do not need the additional functionality of Nagios::Monitoring::Plugin.

EXPORTS

Nagios status code constants are exported by default:

    OK
    WARNING
    CRITICAL
    UNKNOWN
    DEPENDENT

as are the following functions:

    nagios_exit
    nagios_die
    check_messages

The following variables and functions are exported only on request:

    %ERRORS
    %STATUS_TEXT
    get_shortname
    max_state
    max_state_alt

FUNCTIONS

The following functions are supported:

nagios_exit( <CODE>, $message )

Exit with return code CODE, and a standard nagios message of the form "PLUGIN CODE - $message".

nagios_die( $message, [CODE] )

Same as nagios_exit(), except that CODE is optional, defaulting to UNKNOWN. NOTE: exceptions are not raised by default to calling code. Set $_use_die flag if this functionality is required (see test code).

check_messages( critical => \@crit, warning => \@warn )

Convenience function to check a set of message arrays and return an appropriate nagios return code and/or a result message. Returns only a return code in scalar context; returns a return code and an error message in list context i.e.

    # Scalar context
    $code = check_messages(critical => \@crit, warning => \@warn);
    # List context
    ($code, $msg) = check_messages(critical => \@crit, warning => \@warn);

check_messages() accepts the following named arguments:

critical => ARRAYREF

An arrayref of critical error messages - check_messages() returns CRITICAL if this arrayref is non-empty. Mandatory.

warning => ARRAYREF

An arrayref of warning error messages - check_messages() returns WARNING if this arrayref is non-empty ('critical' is checked first). Mandatory.

ok => ARRAYREF | SCALAR

An arrayref of informational messages (or a single scalar message), used in list context if both the 'critical' and 'warning' arrayrefs are empty. Optional.

join => SCALAR

A string used to join the relevant array to generate the message string returned in list context i.e. if the 'critical' array @crit is non-empty, check_messages would return:

    join( $join, @crit )

as the result message. Optional; default: ' ' (space).

join_all => SCALAR

By default, only one set of messages are joined and returned in the result message i.e. if the result is CRITICAL, only the 'critical' messages are included in the result; if WARNING, only the 'warning' messages are included; if OK, the 'ok' messages are included (if supplied) i.e. the default is to return an 'errors-only' type message.

If join_all is supplied, however, it will be used as a string to join the resultant critical, warning, and ok messages together i.e. all messages are joined and returned.

get_shortname

Return the default shortname used for this plugin i.e. the first token reported by nagios_exit/nagios_die. The default is basically

    uc basename( $ENV{NAGIOS_PLUGIN} || $0 )

with any leading 'CHECK_' and trailing file suffixes removed.

get_shortname is not exported by default, so must be explicitly imported.

max_state(@a)

Returns the worst state in the array. Order is: CRITICAL, WARNING, OK, UNKNOWN, DEPENDENT

The typical usage of max_state is to initialise the state as UNKNOWN and use it on the result of various test. If no test were performed successfully the state will still be UNKNOWN.

max_state_alt(@a)

Returns the worst state in the array. Order is: CRITICAL, WARNING, UNKNOWN, DEPENDENT, OK

This is a true definition of a max state (OK last) and should be used if the internal tests performed can return UNKNOWN.

SEE ALSO

Nagios::Monitoring::Plugin; the nagios plugin developer guidelines at https://nagios-plugins.org/doc/guidelines.html.

AUTHORS

This code is maintained by the Nagios Plugin Development Team: https://nagios-plugins.org/

COPYRIGHT AND LICENSE

Copyright (C) 2006-2015 by Nagios Plugin Development Team

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.