#!/bin/bash
#
# Monitors NF conntrack value
#   SYSENG-14373
#

_chk_name="nf_conntrack_monitor"

_nf_warn="50"
_nf_crit="75"

if [[ ! -f /proc/sys/net/netfilter/nf_conntrack_count || ! -f /proc/sys/net/netfilter/nf_conntrack_max ]]; then
  echo "nf_conntrack - nf_conntrack module does not appear to be loaded!"
  exit 2
else
  _nfcount=$(cat /proc/sys/net/netfilter/nf_conntrack_count)
  _nfmax=$(cat /proc/sys/net/netfilter/nf_conntrack_max)

  _nf_warn_value=$(( _nfmax * _nf_warn / 100 ))
  _nf_crit_value=$(( _nfmax * _nf_crit / 100 ))

  _percentage_count=$(( _nfcount * 100 / _nfmax ))
  if [[ ${_percentage_count} -gt ${_nf_crit} ]]; then
    echo "nf_conntrack_count - ${_nfcount} NFconntrack is getting full (${_percentage_count}%) :sadserver:, please investigate."
    exit 2
  elif [[ ${_percentage_count} -gt ${_nf_warn} ]]; then
    echo "nf_conntrack_count - ${_nfcount} WARN"
    exit 1
  else
    echo "nf_conntrack_count - ${_nfcount} OK"
    exit 0
  fi
fi