# Check free space on Windows volume mount points
# 
# This script will execute checks against volume mount points using WMI via powershell and nsclient++ 
# 
# 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.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
#
# Revision History
# 2013-08-14	Barry Mulholland [basra.mulholland@gmail.com]	1.0
#															* Initial script created
#
# To execute from within NSClient++
#
#[NRPE Handlers]
#check_windows_volume_mount_point_freespace=cmd /c echo Scripts\CheckWindowsVolumeMountPointFreeSpace.ps1; exit($lastexitcode) | PowerShell.exe -Command -
#
# On the check_nrpe command include the -t 20, since it takes some time to load the cmdlet's.


$server = $env:computername
$NagiosStatus = "0"
$NagiosDescription = ""
$Critical = 5
$Warning = 10


$volumes = Get-WmiObject -computer $server win32_volume | Where-object {$_.DriveLetter -eq $null -and $_.Label -notlike "*System Reserved*"} | ForEach-Object {
	$Label = $_.Label
	#Calculate totals in GB, round to 2 decimal places
	$TotalGB = [math]::round(($_.Capacity/ 1073741824),2)
	$FreeGB = [math]::round(($_.FreeSpace / 1073741824),2)
	#Calculate free space as percentage, 
	$FreePerc = [math]::round(((($_.FreeSpace / 1073741824)/($_.Capacity / 1073741824)) * 100),0)

	#Check to see if volume free space is less than $Critical
	if ($FreeGB -lt $Critical)
	{
		#Format for Nagios
		if ($NagiosDescription -ne "")
		{
			$NagiosDescription = $NagiosDescription + ", "
		}
		#Add details of failure
		$NagiosDescription = $NagiosDescription + "Volume: " + $Label + " Total Size (GB):" + $TotalGB + ", Free Space (GB):" + $FreeGB + ", Free (%):" + $FreePerc
		#Set the status to failed
		$NagiosStatus = "2"
	}
	#Else check to make sure it's not less than $Warning
	elseif ($FreeGB -lt $Warning)
	{
		#Format for Nagios
		if ($NagiosDescription -ne "")
		{
			$NagiosDescription = $NagiosDescription + ", "
		}
		#Add details of warning
		$NagiosDescription = $NagiosDescription + "Volume: " + $Label + " Total Size (GB):" + $TotalGB + ", Free Space (GB):" + $FreeGB + ", Free (%):" + $FreePerc
		#Set the status to warning
		if ($NagiosStatus -ne "2")
		{
			$NagiosStatus = "1"
		}
	}
}

# Output, final text message for Nagios
if ($NagiosStatus -eq "2")
{
	Write-Host "CRITICAL: " $NagiosDescription
}
elseif ($NagiosStatus -eq "1")
{
	Write-Host "WARNING: " $NagiosDescription
}
else
{
	Write-Host "OK: All volumes have adequate free space"
}

exit $NagiosStatus