#!/bin/bash
# -*- sh -*-

: <<END

=head1 NAME

vhost_requests_ - Wildcard-plugin to monitor http requests by response status code to a particular virtual host.

=head1 CONFIGURATION

Example configuration follows.

  [vhost_requests_*]
    user root

Or you can just give read access to munin.

An example way to create links for all logfiles (remove the \ from the \$s):
for f in \$(ls /var/log/apache2/*access_log) ; do ln -s /usr/share/munin/plugins/vhost_requests_ vhost_requests_\$(basename \$f); done

Also refer to max_lines, logdir, date_format and status_column below if you have any issue, if
you're on fedora you'll need to change at least logdir.

=head2 ENVIRONMENT VARIABLES

This plugin does not use environment variables

=head2 WILDCARD PLUGIN

This is a wildcard plugin.  To show requests by response status code
on a particular virtual host, link vhost_requests_<desired_access_log_filename> to this file.

E.g.

 ln -s /usr/share/munin/plugins/vhost_requests_ /etc/munin/plugins/vhost_requests_host.org-access_log

=head1 AUTHOR

Roberto Rodriguez

=cut
END

# This is the format that date will use to generate access_log like entries
date_format='+%d/%b/%Y:%R'
# This is where apache stores logfiles
logdir=/var/log/apache2

# By default process the whole logfile, but you can set a value different than 0 to limit the lines to process.
# This is useful if the plugin is hurting your performance, a way to calculate this could be:
# The expected requests in five minutes (you can grab this from the maximum value in the y legend)
# / 5 * 6 (Because we left the last minute to the next round)
# times how high can an unexpected peak be (Example 3 times)
# So, if we have 1000 requests every five minutes max_lines could be:
# 1000 / 5 * 6 * 3 = 3600
# It should improve performance because at 1000 requests per 5 minutes you have 288000 per day but it will only read 3600 each time.
max_lines=0
# If your http status code comes in a different column, you can change it here: (Assuming ' ' is the column separator)
status_column=9

file_name=`basename $0 | sed 's/^vhost_requests_//g'`

case $1 in
   config)
echo graph_category webserver
echo graph_title Requests by Status Code $file_name
echo graph_vlabel Nr of Requests
echo S200.label 200 OK
echo S206.label 206 Partial Content
echo S301.label 301 Moved Permanently
echo S302.label 302 Found
echo S303.label 303 See Other
echo S304.label 304 Not Modified
echo S400.label 400 Bad Request
echo S403.label 403 Forbidden
echo S404.label 404 Not Found
echo S405.label 405 Method Not Allowed
echo S500.label 500 Internal Server Error
echo S502.label 502 Bad Gateway
echo S503.label 503 Service Unavailable
echo S200.draw AREA
echo S206.draw STACK
echo S301.draw STACK
echo S302.draw STACK
echo S303.draw STACK
echo S304.draw STACK
echo S400.draw STACK
echo S403.draw STACK
echo S404.draw STACK
echo S405.draw STACK
echo S500.draw STACK
echo S502.draw STACK
echo S503.draw STACK
        exit 0;;
esac

if [ $max_lines -eq 0 ]
then
	for f in $(seq 5); do grep $(date $date_format -d "-$f min") $logdir/$file_name; done | cut -d' ' -f $status_column | sort | uniq -c | awk '{ print "S"$2".value "$1; }'
else
	for f in $(seq 5); do tail -n $max_lines $logdir/$file_name | grep $(date $date_format -d "-$f min"); done | cut -d' ' -f $status_column | sort | uniq -c | awk '{ print "S"$2".value "$1; }'
fi