#!/usr/bin/perl -w
# -*- cperl -*-
# Magic markers:
#%# family=auto
#%# capabilities=autoconf
# nginx_status --- Determine the current status of Nginx
#                  using the http_stub_status module.

# Copyright (C) 2010 António P. P. Almeida <appa@perusio.net>

# Author: António P. P. Almeida <appa@perusio.net>

# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

# Except as contained in this notice, the name(s) of the above copyright
# holders shall not be used in advertising or otherwise to promote the sale,
# use or other dealings in this Software without prior written authorization.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.

=head1 NAME

nginx_status - Munin plugin to show the connection status for nginx

=encoding utf8

=head1 APPLICABLE SYSTEMS

Any nginx host

=head1 CONFIGURATION

This shows the default configuration of this plugin.  You can override
the status URL and the User Agent.

  [nginx*]
      env.url http://localhost/nginx_status
      env.ua nginx-status-verifier/0.1

Nginx must also be configured.  Firstly the stub-status module must be
compiled, and secondly it must be configured like this:

  server {
        listen 127.0.0.1;
        server_name localhost;
        location /nginx_status {
                stub_status on;
                access_log   off;
                allow 127.0.0.1;
                deny all;
        }
  }

=head1 MAGIC MARKERS

  #%# family=auto
  #%# capabilities=autoconf

=head1 VERSION

1.1

=head1 BUGS

None known

=head1 AUTHOR

Unknown. Mantained by António Almeida <appa@perusio.net>

=head1 REPOSITORY

Source code at http://github.com/perusio/nginx-munin

=head1 LICENSE

MIT

=cut

my $ret = undef;

if (! eval "require LWP::UserAgent;") {
  $ret = "LWP::UserAgent not found";
}

chomp(my $fqdn=`hostname -f`);

## Environment defined variables.
## The default URL is nginx_status if different set it in the environment.
my $URL = exists $ENV{'url'} ? $ENV{'url'} : "http://$fqdn/nginx_status";
## The default user agent is ngnix-status-verifier/0.1 if different
## set it in the environment.
my $UA = exists $ENV{'ua'} ? $ENV{'ua'} : 'nginx-status-verifier/0.1';


## Munin autoconf method.
if (exists $ARGV[0] and $ARGV[0] eq "autoconf" ) {
  if ($ret) {
    print "no ($ret)\n";
    exit 1;
  }

  my $ua = LWP::UserAgent->new(timeout => 30);
  # Set the UA to something different from the libwww-perl.
  # This UA is blocked.
  $ua->agent($UA);
  my $response = $ua->request(HTTP::Request->new('GET',$URL));

  unless ($response->is_success and $response->content =~ /server/im) {
    print "no (no nginx status on $URL)\n";
    exit 1;
  } else {
    print "yes\n";
    exit 0;
  }
}

## Munin config method.
if (exists $ARGV[0] and $ARGV[0] eq "config") {
  print "graph_title NGINX status\n";
  print "graph_args --base 1000\n";
  print "graph_category nginx\n";
  print "graph_vlabel Connections\n";

  print "total.label Active connections\n";
  print "total.info  Active connections\n";
  print "total.draw LINE2\n";

  print "reading.label Reading\n";
  print "reading.info  Reading\n";
  print "reading.draw LINE2\n";

  print "writing.label Writing\n";
  print "writing.info  Writing\n";
  print "writing.draw LINE2\n";

  print "waiting.label Waiting\n";
  print "waiting.info  Waiting\n";
  print "waiting.draw LINE2\n";

  exit 0;
}

my $ua = LWP::UserAgent->new(timeout => 30);
# Set the UA to something different from the libwww-perl.
# That UA is blocked.
$ua->agent($UA);
my $response = $ua->request(HTTP::Request->new('GET',$URL));

# Active connections: 1845
# server accepts handled requests
# 4566318 4566318 84218236
# Reading: 2 Writing: 278 Waiting: 1565
if ($response->content =~ /Active connections:\s+(\d+).*Reading:\s+(\d+).*Writing:\s+(\d+).*Waiting:\s+(\d+)/s) {
  print "total.value $1\n";
  print "reading.value $2\n";
  print "writing.value $3\n";
  print "waiting.value $4\n";
} else {
  foreach (qw(total reading writing waiting)) {
    print "$_.value U\n";
  }
}