Munin contributed plugins

#!/bin/bash

# -*- bash -*-

: <<=cut

=head1 NAME

nginx error - Munin plugin to monitor nginx error rates (http status codes per minute).

=head1 APPLICABLE SYSTEMS

Any Linux host, running nginx, with bash version > 4.0

=head1 CONFIGURATION

This shows the default configuration of this plugin.  You can override

the log file path and the logpattern.

  [nginx_error]

	env.logpath    /var/log/nginx

	env.logpattern a.*.log

	Nginx must also be configured to log accesses in "combined" log format (default)

=head1 USAGE

Link this plugin to /etc/munin/plugins/ and restart the munin-node.

This plugin also can be used like wildcard-plugin for monitoring particular virtual host log.

E.g.

    ln -s /usr/share/munin/plugins/nginx_error /etc/munin/plugins/nginx_error_mydomaincom

will parse the log file /var/log/nginx/a.mydomaincom.log

You can change 'env.logpattern' using asterisk ('*') to match your logs filenames.

=head1 INTERPRETATION

The plugin shows nginx http "error" status rates by parsing access log.

=head1 MAGIC MARKERS

 #%# family=auto

 #%# capabilities=autoconf

=head1 BUGS

None known.

=head1 VERSION

$Id:$

=head1 AUTHOR

vovansystems@gmail.com, 2013

=head1 LICENSE

GPLv3

=cut

if [ -z $logpath ]; then

  logpath='/var/log/nginx'

fi

name=`basename $0`

domain=${name/nginx_error/}

if [[ $domain != '_' && ${#domain} -ne 0 ]]; then

  domain=${domain:1}

  if [ -z $logpattern ]; then

    logpattern='a.*.log'

  fi

  logpattern=${logpattern/\*/$domain}

else

  logpattern='access.log'

fi

log="$logpath/$logpattern"

# declaring an array with http status codes, we are interested in

declare -A http_codes

http_codes[400]='Bad Request'

http_codes[401]='Unauthorized'

http_codes[403]='Forbidden'

http_codes[404]='Not Found'

http_codes[405]='Method Not Allowed'

http_codes[406]='Not Acceptable'

http_codes[408]='Request Timeout'

http_codes[429]='Too Many Requests'

http_codes[499]='Client Connection Terminated'

http_codes[500]='Internal Server Error'

http_codes[502]='Bad Gateway'

http_codes[503]='Service Unavailable'

do_ () { # Fetch

  for k in ${!http_codes[@]}; do

    #value=`awk -v k=$k '{if ($9 == k) { print $9 }}' $log | wc -l` # this is very slow and ugly

    value=`awk -v k=$k '{if ($9 == k) { i += 1 }} END { print i }' $log` # this is much better

    echo "error$k.value ${value:-0}"

  done

  exit 0

}

do_config () {

  echo "graph_title $logpattern - Nginx errors per minute"

  echo 'graph_vlabel pages with http error codes / ${graph_period}'

  echo "graph_category nginx"

  echo "graph_period minute"

  echo "graph_info This graph shows nginx error amount per minute"

  for k in ${!http_codes[@]}; do

    echo "error$k.type DERIVE"

    echo "error$k.min 0"

    echo "error$k.label $k ${http_codes[$k]}"

  done

  exit 0

}

do_autoconf () {

  echo yes

  exit 0

}

case $1 in

  config|autoconf|'')

  eval do_$1

esac

exit $?