#!/bin/bash
# Copyright (C) 2008-2010  Equinox Software, Inc.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# postgres Backend Count
# Written by: Equinox Software, September 22, 2010 - Lee Dickens
# Modified by: Equinox Software, March 13, 2014 - Michael Tate
USAGE="check_backends2 <max_connnections (default 800 if empty)> <pool|pg (default pg if empty)>"
if [[ $1 == *help* ]]; then
  echo "Usage: $USAGE"
  exit 0
fi

## GET/SET Variables ##
# Use "max_connections" from postgresql.conf
if [ -n "$1" ]; then
  MAXCX=$1
else
  MAXCX="800"
#  MAXCX=`grep max_connections $(find /etc/postgresql/ -name postgresql.conf|tail -n1)` | grep -v "^#"|tr -cd '[[:digit:]]{}'`
fi

# Platform: plain postgres or pgpool
if [ -n "$2" ]; then
  PLATCX=$2
else
  PLATCX="pg"
fi

if [[ $PLATCX == "pg" ]]; then
 PGCX=$MAXCX
 # PG warn and crit, high and low
 PGCXWL=$(($PGCX/10))           # PostgreSQL number of connections WARN level, low (10% of max)
 PGCXCL=$(($PGCXWL/2))          # PostgreSQL number of connections CRIT level, low (5% of max)
 PGCXC=$(($PGCX-$PGCXWL))    # PostgreSQL number of connections CRIT level, high (90% of max)
 PGCXW=$(($PGCXC-$PGCXWL))       # PostgreSQL number of connections WARN level, high (80% of max)
 PGACT=`ps ax|grep -v grep | grep -c postgres`

 if [ $PGACT -lt $PGCXCL ]; then
   EXITSTATUS="CRIT: postgresql backends = $PGACT/$PGCX"
   EXITCODE=2
 elif [ $PGACT -lt $PGCXWL ]; then
   EXITSTATUS="WARN: postgresql backends = $PGACT/$PGCX"
   EXITCODE=1
 elif [ $PGACT -gt $PGCXW ]; then
   EXITSTATUS="WARN: postgresql backends = $PGACT/$PGCX"
   EXITCODE=1
 elif [ $PGACT -gt $PGCXW ]; then
   EXITSTATUS="CRIT: postgresql backends = $PGACT/$PGCX"
   EXITCODE=2
 else
   EXITSTATUS="OK: postgresql backends = $PGACT/$PGCX"
   EXITCODE=0
 fi

elif [[ $PLATCX == "pool" ]]; then
 POOLCX=$MAXCX
 # PGPOOL warn and crit, high and low
 POOLCXWL=$(($PGCX/10))           # PostgreSQL number of connections WARN level, low (10% of max)
 POOLCXCL=$(($PGCXWL/2))          # PostgreSQL number of connections CRIT level, low (5% of max)
 POOLCXC=$(($PGCX-$PGCXWL))    # PostgreSQL number of connections CRIT level, high (90% of max)
 POOLCXW=$(($PGCXC-$PGCXWL))       # PostgreSQL number of connections WARN level, high (80% of max)
 POOLACT=`ps ax|grep -v "wait\|grep" | grep -c pgpool`

 if [ $POOLACT -lt $POOLACTCXCL ]; then
   EXITSTATUS="CRIT: postgresql backends = $PGACT/$PGCX and pgpool backends = $POOLACT/$POOLACTCX"
   EXITCODE=2
 elif [ $POOLACT -lt $POOLACTCXWL ]; then
   EXITSTATUS="WARN: postgresql backends = $PGACT/$PGCX and pgpool backends = $POOLACT/$POOLACTCX"
   EXITCODE=1
 elif [ $POOLACT -gt $POOLACTCXC ]; then
   EXITSTATUS="CRIT: postgresql backends = $PGACT/$PGCX and pgpool backends = $POOLACT/$POOLACTCX"
   EXITCODE=2
 elif [ $POOLACT -gt $POOLACTCXW ]; then
   EXITSTATUS="WARN: postgresql backends = $PGACT/$PGCX and pgpool backends = $POOLACT/$POOLACTCX"
   EXITCODE=1
 else
   EXITSTATUS="OK: pgpool backends = $POOLACT/$POOLACTCX"
   EXITCODE=0
 fi

else
  echo "Usage: $USAGE"
  exit 0
fi


echo "$EXITSTATUS"
exit $EXITCODE