Nagios::Plugin(3) User Contributed Perl Documentation Nagios::Plugin(3)NAMENagios::Plugin - A family of perl modules to streamline writing Nagios
plugins
SYNOPSIS
# Constants OK, WARNING, CRITICAL, and UNKNOWN are exported by default
# See also Nagios::Plugin::Functions for a functional interface
use Nagios::Plugin;
# Constructor
$np = Nagios::Plugin->new; # OR
$np = Nagios::Plugin->new( shortname => "PAGESIZE" ); # OR
# use Nagios::Plugin::Getopt to process the @ARGV command line options:
# --verbose, --help, --usage, --timeout and --host are defined automatically.
$np = Nagios::Plugin->new(
usage => "Usage: %s [ -v|--verbose ] [-H <host>] [-t <timeout>] "
. "[ -c|--critical=<threshold> ] [ -w|--warning=<threshold> ]",
);
# add valid command line options and build them into your usage/help documentation.
$np->add_arg(
spec => 'warning|w=s',
help => '-w, --warning=INTEGER:INTEGER . See '
. 'http://nagiosplug.sourceforge.net/developer-guidelines.html#THRESHOLDFORMAT '
. 'for the threshold format. ',
);
# Parse @ARGV and process standard arguments (e.g. usage, help, version)
$np->getopts;
# Exit/return value methods - nagios_exit( CODE, MESSAGE ),
# nagios_die( MESSAGE, [CODE])
$page = retrieve_page($page1)
or $np->nagios_exit( UNKNOWN, "Could not retrieve page" );
# Return code: 3;
# output: PAGESIZE UNKNOWN - Could not retrieve page
test_page($page)
or $np->nagios_exit( CRITICAL, "Bad page found" );
# nagios_die() is just like nagios_exit(), but return code defaults
# to UNKNOWN
$page = retrieve_page($page2)
or $np->nagios_die( "Could not retrieve page" );
# Return code: 3;
# output: PAGESIZE UNKNOWN - Could not retrieve page
# Threshold methods
$code = $np->check_threshold(
check => $value,
warning => $warning_threshold,
critical => $critical_threshold,
);
$np->nagios_exit( $code, "Threshold check failed" ) if $code != OK;
# Message methods (EXPERIMENTAL AND SUBJECT TO CHANGE) -
# add_message( CODE, $message ); check_messages()
for (@collection) {
if (m/Error/) {
$np->add_message( CRITICAL, $_ );
} else {
$np->add_message( OK, $_ );
}
}
($code, $message) = $np->check_message();
nagios_exit( $code, $message );
# If any items in collection matched m/Error/, returns CRITICAL and
# the joined set of Error messages; otherwise returns OK and the
# joined set of ok messages
# Perfdata methods
$np->add_perfdata(
label => "size",
value => $value,
uom => "kB",
threshold => $threshold,
);
$np->add_perfdata( label => "time", ... );
$np->nagios_exit( OK, "page size at http://... was ${value}kB" );
# Return code: 0;
# output: PAGESIZE OK - page size at http://... was 36kB \
# | size=36kB;10:25;25: time=...
DESCRIPTIONNagios::Plugin and its associated Nagios::Plugin::* modules are a
family of perl modules to streamline writing Nagios plugins. The main
end user modules are Nagios::Plugin, providing an object-oriented
interface to the entire Nagios::Plugin::* collection, and
Nagios::Plugin::Functions, providing a simpler functional interface to
a useful subset of the available functionality.
The purpose of the collection is to make it as simple as possible for
developers to create plugins that conform the Nagios Plugin guidelines
(http://nagiosplug.sourceforge.net/developer-guidelines.html).
EXPORTS
Nagios status code constants are exported by default:
OK
WARNING
CRITICAL
UNKNOWN
DEPENDENT
The following variables are also exported on request:
%ERRORS
A hash mapping error strings ("CRITICAL", "UNKNOWN", etc.) to the
corresponding status code.
%STATUS_TEXT
A hash mapping status code constants (OK, WARNING, CRITICAL, etc.)
to the corresponding error string ("OK", "WARNING, "CRITICAL",
etc.) i.e. the reverse of %ERRORS.
CONSTRUCTOR
Nagios::Plugin->new;
Nagios::Plugin->new( shortname => 'PAGESIZE' );
Nagios::Plugin->new(
usage => "Usage: %s [ -v|--verbose ] [-H <host>] [-t <timeout>]
[ -c|--critical=<critical threshold> ] [ -w|--warning=<warning threshold> ] ",
version => $VERSION,
blurb => $blurb,
extra => $extra,
url => $url,
license => $license,
plugin => basename $0,
timeout => 15,
);
Instantiates a new Nagios::Plugin object. Accepts the following named
arguments:
shortname
The 'shortname' for this plugin, used as the first token in the
plugin output by the various exit methods. Default: uc basename $0.
usage ("Usage: %s --foo --bar")
Passing a value for the usage() argument makes Nagios::Plugin
instantiate its own "Nagios::Plugin::Getopt" object so you can
start doing command line argument processing. See "CONSTRUCTOR" in
Nagios::Plugin::Getopt for more about "usage" and the following
options:
version
url
blurb
license
extra
plugin
timeout
OPTION HANDLING METHODS
"Nagios::Plugin" provides these methods for accessing the functionality
in "Nagios::Plugin::Getopt".
add_arg
Examples:
# Define --hello argument (named parameters)
$plugin->add_arg(
spec => 'hello=s',
help => "--hello\n Hello string",
required => 1,
);
# Define --hello argument (positional parameters)
# Parameter order is 'spec', 'help', 'default', 'required?'
$plugin->add_arg('hello=s', "--hello\n Hello string", undef, 1);
See "ARGUMENTS" in Nagios::Plugin::Getopt for more details.
getopts()
Parses and processes the command line options you've defined,
automatically doing the right thing with help/usage/version
arguments.
See "GETOPTS" in Nagios::Plugin::Getopt for more details.
opts()
Assuming you've instantiated it by passing 'usage' to new(), opts()
returns the Nagios::Plugin object's "Nagios::Plugin::Getopt"
object, with which you can do lots of great things.
E.g.
if ( $plugin->opts->verbose ) {
print "yah yah YAH YAH YAH!!!";
}
# start counting down to timeout
alarm $plugin->opts->timeout;
your_long_check_step_that_might_time_out();
# access any of your custom command line options,
# assuming you've done these steps above:
# $plugin->add_arg('my_argument=s', '--my_argument [STRING]');
# $plugin->getopts;
print $plugin->opts->my_argument;
Again, see Nagios::Plugin::Getopt.
EXIT METHODS
nagios_exit( <CODE>, $message )
Exit with return code CODE, and a standard nagios message of the
form "SHORTNAME 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).
die( $message, [<CODE>] )
Alias for nagios_die(). Deprecated.
max_state, max_state_alt
These are wrapper function for Nagios::Plugin::Functions::max_state
and Nagios::Plugin::Functions::max_state_alt.
THRESHOLD METHODS
These provide a top level interface to the "Nagios::Plugin::Threshold"
module; for more details, see Nagios::Plugin::Threshold and
Nagios::Plugin::Range.
check_threshold( $value )
check_threshold( check => $value, warning => $warn, critical => $crit )
Evaluates $value against the thresholds and returns OK, CRITICAL,
or WARNING constant. The thresholds may be:
1. explicitly set by passing 'warning' and/or 'critical' parameters
to
"check_threshold()", or,
2. explicitly set by calling "set_thresholds()" before
"check_threshold()", or,
3. implicitly set by command-line parameters -w, -c, --critical or
--warning, if you have run "$plugin->getopts()".
The return value is ready to pass to C <nagios_exit>, e . g .,
$p->nagios_exit(
return_code => $p->check_threshold($result),
message => " sample result was $result"
);
set_thresholds(warning => "10:25", critical => "~:25")
Sets the acceptable ranges and creates the plugin's
Nagios::Plugins::Threshold object. See
http://nagiosplug.sourceforge.net/developer-guidelines.html#THRESHOLDFORMAT
for details and examples of the threshold format.
threshold()
Returns the object's "Nagios::Plugin::Threshold" object, if it has
been defined by calling set_thresholds(). You can pass a new
Threshold object to it to replace the old one too, but you
shouldn't need to do that from a plugin script.
MESSAGE METHODS
EXPERIMENTAL AND SUBJECT TO CHANGE
add_messages and check_messages are higher-level convenience methods to
add and then check a set of messages, returning an appropriate return
code and/or result message. They are equivalent to maintaining a set of
@critical, @warning, and and @ok message arrays (add_message), and then
doing a final if test (check_message) like this:
if (@critical) {
nagios_exit( CRITICAL, join(' ', @critical) );
}
elsif (@warning) {
nagios_exit( WARNING, join(' ', @warning) );
}
else {
nagios_exit( OK, join(' ', @ok) );
}
add_message( <CODE>, $message )
Add a message with CODE status to the object. May be called
multiple times. The messages added are checked by check_messages,
following.
Only CRITICAL, WARNING, and OK are accepted as valid codes.
check_messages()
Check the current set of messages and return an appropriate nagios
return code and/or a result message. In scalar context, returns
only a return code; in list context returns both a return code and
an output message, suitable for passing directly to nagios_exit()
e.g.
$code = $np->check_messages;
($code, $message) = $np->check_messages;
check_messages returns CRITICAL if any critical messages are found,
WARNING if any warning messages are found, and OK otherwise. The
message returned in list context defaults to the joined set of
error messages; this may be customised using the arguments below.
check_messages accepts the following named arguments (none are
required):
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. 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.
critical => ARRAYREF
Additional critical messages to supplement any passed in via
add_message().
warning => ARRAYREF
Additional warning messages to supplement any passed in via
add_message().
ok => ARRAYREF | SCALAR
Additional ok messages to supplement any passed in via
add_message().
PERFORMANCE DATA METHODS
add_perfdata( label => "size", value => $value, uom => "kB", threshold
=> $threshold )
Add a set of performance data to the object. May be called multiple
times. The performance data is included in the standard plugin
output messages by the various exit methods.
See the Nagios::Plugin::Performance documentation for more
information on performance data and the various field definitions,
as well as the relevant section of the Nagios Plugin guidelines
(http://nagiosplug.sourceforge.net/developer-guidelines.html#AEN202).
EXAMPLES
"Enough talk! Show me some examples!"
See the file 'check_stuff.pl' in the 't' directory included with the
Nagios::Plugin distribution for a complete working example of a plugin
script.
VERSIONING
The Nagios::Plugin::* modules are currently experimental and so the
interfaces may change up until Nagios::Plugin hits version 1.0,
although every attempt will be made to keep them as backwards
compatible as possible.
SEE ALSO
See Nagios::Plugin::Functions for a simple functional interface to a
subset of the available Nagios::Plugin functionality.
See also Nagios::Plugin::Getopt, Nagios::Plugin::Range,
Nagios::Plugin::Performance, Nagios::Plugin::Range, and
Nagios::Plugin::Threshold.
The Nagios Plugin project page is at http://nagiosplug.sourceforge.net.
BUGS
Please report bugs in these modules to the Nagios Plugin development
team: nagiosplug-devel@lists.sourceforge.net.
AUTHOR
Maintained by the Nagios Plugin development team -
http://nagiosplug.sourceforge.net.
Originally by Ton Voon, <ton.voon@altinity.com>.
COPYRIGHT AND LICENSE
Copyright (C) 2006 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, either Perl version 5.8.4 or, at
your option, any later version of Perl 5 you may have available.
perl v5.14.1 2010-12-03 Nagios::Plugin(3)
