#!/usr/bin/env bash

# nscd (name server caching daemon) statistics
#
# Tested with nscd 2.13 on Debian 7.8
#
# This plugin is capable to show:
# - per-database (passwd, group, hosts, services):
#     - Suggested size
#     - Cache hit rate
#     - Number of currently cached values
#     - Number of max cached values
#
# Required permissions:
# - root permissions to run "nscd -g"
#
# OS: *NIX
#
# Author: Oliver Ladner <waste@lugh.ch>
#
# Configuration:
# - set env.nscd_cfg to nscd.conf path if necessary
# - Configure to run as root in /etc/munin/plugin-conf.d/munin-node
#   [nscd_*]
#    user root
#
# Notes:
#
# A low cache hit rate in combination with a shared cache configuration is
# normal, as clients can search the cache directly without asking the nscd
# daemon first. See http://goo.gl/dkwzDH

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

. "$MUNIN_LIBDIR/plugins/plugin.sh"
NSCD_CFG=${nscd_cfg:-/etc/nscd.conf}
AUTOCONF_CHECK=$(nscd -g | grep -ic 'yes.*cache is enabled')
SUGGEST_CHECK=$(nscd -g | grep -iB2 'yes.*cache is enabled' | awk '{print $1}' | head -1)
MODE=$(basename "$0" | sed 's/^nscd_//g' | tr '_' '.')

case $1 in
	autoconf)
		if [ -r "$NSCD_CFG" ] && [ "$AUTOCONF_CHECK" -gt 0 ]; then
			echo yes
		else
			echo "no (nscd config not found or no database enabled)"
		fi
		exit 0
		;;
	suggest)
		echo "$SUGGEST_CHECK"
		exit 0
		;;
	config)
		# --lower-limit needs to be > 0 for logarithmic scaling
		cat <<CONFIG
graph_args --base 1000  --lower-limit 0
graph_scale yes
graph_title nscd - ${MODE//_/ } cache
graph_info This graph shows nscd $MODE statistics
graph_vlabel % or count
suggestedsize.label Suggested size
cachehitrate.label Cache hit rate in %
cachehitrate.info A low cache hit rate in combination with a shared cache configuration is normal, as clients can search the cache directly without asking the nscd daemon first
currnumber.label Current number of cached values
maxnumber.label Maximum number of cached values
graph_category system
CONFIG
		;;
	fetch|*)
			nscd -g | awk "/^$MODE cache/ {printline = 1; print; next} /^.*cache:/ {printline = 0} printline" | \
			grep -E '(suggested size|cache hit rate|current number of cached values|maximum number of cached values)' | \
			sed 's/%//' | awk '{ if (NR==1) print "suggestedsize.value " $1; if (NR==2) print "cachehitrate.value " $1; if (NR==3) print "currnumber.value " $1; if (NR==4) print "maxnumber.value " $1}'
		;;
esac