Powershell script for updating Octopus Tentacles to 2.x

UpgradeTentacle.ps1

function Uninstall-OldTentacle {
  Write-Output "Uninstalling the 1.0 Tentacle"

  $app = Get-WmiObject -Query "SELECT * FROM Win32_Product WHERE Name = 'Octopus Deploy Tentacle' AND Version < 2.0"          
  $app.Uninstall()
  
  & sc.exe delete "Octopus Tentacle"
}

function Upgrade-Tentacle
{ 
  Write-Output "Beginning Tentacle installation"
  Write-Output "Downloading Octopus Tentacle MSI..."
  $downloader = new-object System.Net.WebClient
  $downloader.DownloadFile("http://download.octopusdeploy.com/octopus/Octopus.Tentacle.2.0.13.1100-x64.msi", "Tentacle.msi")
  
  Write-Output "Installing MSI"
  $msiExitCode = (Start-Process -FilePath "msiexec.exe" -ArgumentList "/i Tentacle.msi /quiet" -Wait -Passthru).ExitCode
  Write-Output "Tentacle MSI installer returned exit code $msiExitCode"
  if ($msiExitCode -ne 0) {
    throw "Installation aborted"
  }
  
  Write-Output "Configuring and registering Tentacle"
   
  cd "${env:ProgramFiles}\Octopus Deploy\Tentacle"
  Write-Output "Configuring the 2.0 Tentacle"
  
  & .\tentacle.exe create-instance --instance "Tentacle" --config "${env:SystemDrive}\Octopus\Tentacle\Tentacle.config" --console
  & .\tentacle.exe configure --instance "Tentacle" --home "${env:SystemDrive}\Octopus" --console
  & .\tentacle.exe configure --instance "Tentacle" --app "${env:SystemDrive}\Octopus\Applications" --console
  & .\tentacle.exe configure --instance "Tentacle" --port "10933" --console
  & .\tentacle.exe configure --instance "Tentacle" --trust="*** ENTER OCTOPUS KEY HERE ***"
  & .\tentacle.exe import-certificate --instance "Tentacle" --from-registry  --console
  Write-Output "Stopping the 1.0 Tentacle"
  Stop-Service "Octopus Tentacle"
  Write-Output "Starting the 2.0 Tentacle"
  & .\tentacle.exe service --instance "Tentacle" --install --start
  
  Write-Output "Tentacle commands complete"
}

Upgrade-Tentacle
Uninstall-OldTentacle