Automating Registration of PowerPath Licenses using Powershell/PowerCLI

Summary:
EMC documentation is atrocious.  Needless to say, their 'auto-registration' capability is poorly named and represented in my opinion.  It makes you think, deploy a vApp, copy license file, and you're done.  SOOOO NOT the case.  So here is my attempt to hopefully help make the license application portion 'automated' using PowerShell and PowerCLI cmdlets.

PreReq:

1. PowerPath 5.8 License vApp
2. PowerPath License File
3. RTools for Windows

Details:

1. Deploy the vApp
• Generate a license file from EMC's website, you'll need the IP and DNS name of the vApp.
• or contact your EMC support team to have them do it for you.
2. Copy the license file to the vApp's /etc/emc/licenses/ directory
3. Install RTools on a Windows server or your workstation
• I prefer to have my tools on a shared general purpose system.  This allows me to run scheduled scripts from one location.
4. Copy the same license file to C:\ProgramData\My Documents\emc\PowerPath\rpowermt
• The rpowermt tool reads this location to find out the license server IP address and name.
5. Now onto the Powershell portion of this post (Apologies for the formatting, I've been lazy in finding a new editor for Blogger):

#Connecting to vCenter
Connect-VIServer YourvCenterServerName

#Gather hosts in previously connected vCenter
$VMHosts = Get-VMHost

#Getting saved root credentials for esx hosts
#To generate this, you can use the New-VICredentialStore cmdlet
$VICreds = Get-VICredentialStoreItem -File D:\SomePath\RootCreds.xml

#This is where we begin working w/ each individual VM host.
Foreach ($VMHost in $VMHosts)
{
#Here we call the rpowermt executible, inserting the VM host name, and its root credentials
#We are capturing the output of this command into the $LicenseChk variable
$LicenseChk = & 'C:\Program Files (x86)\EMC\PowerPath\rpowermt\rpowermt.exe' check_registration host=$($VMHost.name) username=$($VICreds.User) password=$($VICreds.Password)
#Here we call a switch and do a regex check of the contents of $LicenseChk
    switch -regex ($LicenseChk)
    {
    #If $LicenseChk contains the word unlicensed, we then attempt to register the VM host w/ the license server.
    #A check is made again, if the host is still unlicensed, we output the contents of $LicenseChk to a file and e-mail ourselves to investigate and attempt manual remediation
    #If licensed successfully, we check if a file denoting that has already been generated, if not we output the contents of $LicenseChk to a file.
    #This is simply for record keeping.
    "unlicensed" 
        {
        & 'C:\Program Files (x86)\EMC\PowerPath\rpowermt\rpowermt.exe' register host=$($VMHost.name) username=$($VICreds.User) password=$($VICreds.Password)
        $LicenseChk = & 'C:\Program Files (x86)\EMC\PowerPath\rpowermt\rpowermt.exe' check_registration host=$($VMHost.name) username=$($VICreds.User) password=$($VICreds.Password)
            switch -regex ($LicenseChk)
            {
            "unlicensed" 
                {
                $LicenseChk | Out-File -FilePath C:\SomePath\PowerPathRegistrationFailure$($VMHost.name).txt 
                Send-MailMessage -SmtpServer yoursmtpserver.localdomain -To "AnEmailAddressyouOwn@somewhere.com" -From "ILikeDLs@somewhere.com"  -subject "$($VMHost.Name) PowerPath License Failure" -Body "$($VMHost.Name) failed to register a powerpath license.  Please attempt manually from someserveryourunthisfrom.localdomain"
                }
            "licensed" 
                {
                If (Test-Path C:\SomePath\$($VMHost.name).txt ){}
                Else{$LicenseChk | Out-File -FilePath C:\SomePath\$($VMHost.name).txt }
                }
            }
        }
    "licensed" 
        {
        If (Test-Path C:\SomePath\$($VMHost.name).txt ){}
        Else{$LicenseChk | Out-File -FilePath C:\SomePath\$($VMHost.name).txt }
        }
    }
}

#Once the loop completes, we disconnect from vCenter
Disconnect-VIServer YourvCenterServerName -Confirm:$false