# Watch-UPS.ps1
# powershell v2 CP3
# Version: 1.5
# Date jan 2011
# Latest version: mar 2013
# Author:  Paul Weterings
# www.servercare.nl

# Description:
<#
This script monitors the UPS or Battery connected to the system in the
$computer variable. As soon as it detects that the system is going offline
(hence starts using the UPS/Battery it will compare the percentage
power left to a a list of system names provided in the 'watch-ups.csv' file.

Each system in the .csv list has an associated percentage listed; if the
battery level has dropped below the percentage listed for that system, the
script will send a shutdown request to that system.

The idea is to shut down the least critical systems first, providing them
a 'clean shutdown' rather then an abrupt power off when the UPS is empty.
Additionally; shutting down the least critical systems first will allow
other, possibly more critical systems (such as a NAS or SQL server for
example) to remain on the UPS longer, since it now has to cater to less
systems.

example contents of the .csv file:

systemname, percentage, status
game1, 80, 0
scom1, 80, 0
mail1, 50, 0
sql1, 10, 0
nas1, 5, 0

This means the game and scom servers will be shut down first, when the UPS
is at 80% power left. Since the UPS now has 2 less servers to support, there's
more power for the other servers to remain running during a power failure.
At 50% we stop the mail server, since typically an Exchange server needs some
time to shut down, we sent it the shutdown command fairly soon. We wait until
the very last drops of power left (resp 10% and 5%) to sent the sql and nas
server the shutdown command.

-systemname = needs to be a (network reachable) name of a system on the network.

-percentage = the percentage of power left in the UPS at which we need to send
a shutdown command to this system.

-status = 0 means the system should be shut down,
1 means ' no action' (for test situations for example) BE CAREFUL; after the power
goes off, and then on again the script will 're-arm' and status will be 0
for all servers. This means they will shut down at a second 'power failure'.

actions of this script are logged on screen and to the application eventlog of
the system running it as well as mailed.
#>

# the computer system that we will be measuring; the UPS is connected here.
# CHANGE THIS TO YOUR SYSTEM NAME THAT HAS THE UPS CONNECTED.
# or leave it '.' which is the local system
$computer = "mon1.DOMAIN"

$namespace = "root\CIMV2"
$batstat= @{"1"="battery is discharging";"2"="On AC";"3"="Fully Charged";"4"=`
"Low";"5"="Critical";"6"="Charging";"7"="Charging and High";"8"="Charging and`
 Low";"9"="Charging and Critical";"10"="Undefined";"11"="Partially Charged";}

# We will be sending a mail at each shutdown
# Change this to what you want
$emailFrom = "REMOVED"
# Make this your E-Mail address
$emailTo = "REMOVED"
$subject = "Watch-UPS action"
#Make this your SMTP mail server
$smtpServer = "REMOVED"
$smtp = new-object Net.Mail.SmtpClient($smtpServer)

# for eventlogging purposes:
# we simply want to know if our script was registered with the eventlog already
Get-EventLog -source Watch-UPS -LogName Application -ErrorAction silentlycontinue | Out-Null

if (-not$?)
{
    # there's an error, so we must not be listed yet, lets see to it we exist
    # for eventlogging
    New-EventLog -source Watch-UPS -LogName Application -ErrorAction silentlycontinue | Out-Null
}


# note that any error for Get-WMI object would not be a 'terminating error',
# since the script won't stop # you can't use try/catch or trap to catch any
# errors. I choose to be silent about the error and # handle the result to see
# if an error occurred.
$batinfo = Get-WmiObject -class Win32_Battery -computername $computer -ErrorAction silentlycontinue -namespace $namespace

# we want to check if we could reach a system, and if we did; did it return
# battery info?
# powershell is so great with stuff like this!
if ($? -and $batinfo)
{
     "Battery status on    : " + $computer +" status: "+ $batstat.Get_Item([string]$batinfo.BatteryStatus)
     "Percentage left      : " + $batinfo.EstimatedChargeRemaining

    # Read an interpret the configuration comma seperated values file
    # Note this is a hardcoded path, you could also use the 'Get-Location' cmdlet
    $path = "C:\netshutdown\watch-ups\"#Get-Location
    $lines = Import-Csv "$path\watch-ups.csv"

    # Report to screen what servers we are looking after
    "`nWatch-UPS will manage:"
    $lines
    # And lets show in the eventlog we started (nice to know if you start this script as a task)
    write-eventlog -logname Application -source Watch-UPS -eventID 3001 -entrytype Information -message "Watch-UPS 1.5 started"
    "-------------------------------"
}
else
{
    if ($error)
    {
        "Could not find any battery/UPS information on system: " + $computer
        throw $error[0].Exception
    }
}
$wewereonbattery = $false
$powerstatus = $true

# Never ending story, we keep looping. Don't worry, we're not using much resources. (hardly any)
while($true)
{
    $batinfo = Get-WmiObject -class Win32_Battery -computername $computer -ErrorAction silentlycontinue -namespace $namespace
    if ($?) # No error?
    {
        # Only check if we need to take action (BatteryStatus = 2 is not on AC)
        if ($batinfo.BatteryStatus -ne 2)
        {
            $date = Get-Date
            if ($powerstatus)
            {
                write-eventlog -logname Application -source Watch-UPS -eventID 3003 -entrytype Warning -message "$date : power failure detected" -category 1
                $powerstatus = $false
            }
            $wewereonbattery = $true
            # Iterate through all the systems we have found in the config file
            # and check their reboot-percentages against our UPS percentage
            foreach ($system in $lines)
            {
                # Do we have a winner?
                if ($batinfo.EstimatedChargeRemaining -le $system.percentage -and $system.status -eq 0)
                {
                    # We are shutting down the system, lets log it in the
                    # eventlog and put it on screen
                    $date = Get-Date
                    $report = "$date : shutting down " + $system.systemname + " at " + $system.percentage +"% power left."
                    write-eventlog -logname Application -source Watch-UPS -eventID 3002 -entrytype Information -message $report -category 1
                    $report
                    # This assumes the script is being run with credentials
                    # that allow shutting down the remote system.
                    # Use a service account with the correct rights to run this if you start this script as a task.
                    #
                    # If you really want credentials:
                    # (gwmi win32_operatingsystem -ComputerName MyServer
                    # -cred (get-credential)
                    # where (get-credential) can be replaced with credentials
                    # (not a good idea to put credentials in a script!)

                    # msdn.microsoft.com/en-us/library/aa394058(VS.85).aspx
                    $shutsys = gwmi win32_operatingsystem -ComputerName $system.systemname -ErrorAction silentlycontinue
                    if($?) # Did the WMI operation go OK?
                    {
                        # WMI has found the system, so we should be able to
                        # send it a shutdown command
                        $shutsys.Win32Shutdown(12)
                        # remember that we have sent this system a shutdown
                        # command, so we only do it once for each powerloss,
                        # we store this status (1) with the system info.
                        $system.status =1

                        # Lets notify the user by sending an E-Mail
                        $body = $system.systemname + " was sent the shutdown command."
                        $smtp.Send($emailFrom, $emailTo, $subject, $body)
                    }
                    else
                    {
                        $body = $system.systemname + ": The system to shut down was not reached"
                        # it wasn't there, so we ignore it from now on
                        $system.status =-1
                        $smtp.Send($emailFrom, $emailTo, $subject, $body)
                        write-eventlog -logname Application -source Watch-UPS -eventID 3003 -entrytype Warning -message $body -category 1
                    }
                }
            }
        }
        else
        {   # Since the UPS is appearantly on AC, all systems need to
            # be "shutdownable".
            # we basically " re-arm" the status after a potental powerloss
            # may have previously shut down systems but the script kept running
            # as power was restored.
            # We only do this after we initially lost power once...
            if ($wewereonbattery)
            {
                $date = Get-Date
                if ($powerstatus -eq $false)
                {
                    write-eventlog -logname Application -source Watch-UPS -eventID 3003 -entrytype Information -message "$date : AC power detected" -category 1
                    $powerstatus = $true
                }
                foreach ($system in $lines)
                {
                    $system.status = 0
                }
            }
        }
    }
    else
    {
        $date = Get-Date
        "$date : No UPS system found - was it shut down?"
    }

    # Lets wait a second
    Start-Sleep -Seconds 1
}