So you want to upgrade some VDAs?! Yeah you do! I’ve done some edits on other scripts. I’m also working out for additional revisions to check for present sessions. This targets the Server VDA version. You can edit the name to VDAWorkstationSetup_1912.exe in the script and accompanying files to upgrade on VDI as well. The base for this is listed below in the script from ChayScripts. You can also change the install switches and copy that into the install.bat file if you need different options (https://www.citrix.com/blogs/2018/01/08/citrix-vda-commandline-helper-tool/)

For the contents of the ServerNameTextFile, you will need FQDN of the servers for the invoke commands. This splits the FQDN off for the powercli aspect to snapshot the server.

# Base VDA removal / reinstall script. This uses Powershell ISE on 5.1 with needing to be ran with account with rights in VMware and on the target server as well as the module for PowerCLI. 
# Modified from https://github.com/ChayScripts/Citrix-VDA-Upgrade-Scripts scripts. Added snapshot for VMware and a report of previous versions.

$vdalist = get-content "C:\pathtotextfilewithfqdnservernames.txt"
$source = "placewherefilesarestored\vdaupgrade"
$dest = "c$\software\vdaupgrade"
$date = Get-Date -Format MMddyyyy
$report = @()

  foreach ($vda in $vdalist) {
    $line = "" | Select Name, PreviousVersion, SnapShot
    $vda1 = ($vda.split('.')[0])
    $line.Name = "$vda"
    $line.PreviousVersion = (invoke-command -ComputerName $vda -ScriptBlock {Get-WmiObject -Class Win32_Product | where name -match "Citrix Virtual Desktop Agent - x64" | select Name,Version}).Version
    $snapshot = (get-vm $vda1  | new-snapshot -name $date-$vda1-preupgrade)
    $line.SnapShot = (get-vm $vda1 | get-snapshot).name
    Write-Host "Working on $vda"
    if (!(Test-Path -Path \\$vda\c$\software\vdaupgrade)) {
        New-Item -ItemType Directory -Path \\$vda\c$\software -Name vdaupgrade
        Copy-Item "\\$source\install.bat" -Destination \\$vda\$dest -Force
        Copy-Item "\\$source\remove.bat" -Destination \\$vda\$dest -Force
        Copy-Item "\\$source\VDAServerSetup_1912.exe" -Destination \\$vda\$dest -Force
    }
    else {
        Copy-Item "\\$source\install.bat" -Destination \\$vda\$dest -Force
        Copy-Item "\\$source\remove.bat" -Destination \\$vda\$dest -Force
        Copy-Item "\\$source\VDAServerSetup_1912.exe" -Destination \\$vda\$dest -Force

    }
    Invoke-Command -ComputerName $vda -Scriptblock {
        $time = (Get-Date).AddMinutes(3)
        $action = New-ScheduledTaskAction -Execute 'c:\software\vdaupgrade\remove.bat'
        $trigger = New-ScheduledTaskTrigger -Once -At $time
        $principal = New-ScheduledTaskPrincipal  -RunLevel Highest -UserID "NT AUTHORITY\SYSTEM" -LogonType S4U

        Register-ScheduledTask -Action $action -Trigger $trigger -Principal $principal -TaskName "VDAUninstall" -Description "Citrix VDA Uninstall" 
    }

    Invoke-Command -ComputerName $vda -Scriptblock {
        $action = New-ScheduledTaskAction -Execute 'c:\software\vdaupgrade\install.bat'
        $trigger = New-ScheduledTaskTrigger -AtStartup 
        $principal = New-ScheduledTaskPrincipal  -RunLevel Highest -UserID "NT AUTHORITY\SYSTEM" -LogonType S4U

        Register-ScheduledTask -Action $action -Trigger $trigger -Principal $principal -TaskName "VDAInstall" -Description "Citrix VDA Install" 

    } 

    $report += $line

  }

$report | export-csv c:\scripts\logs\$date-vda-upgrades.csv -Append -NoTypeInformation

You will need to create an install.bat and remove.bat file with the contents below.

Install.bat
REM change port number in below command.
REM Use citrix vda command line helper tool from citrix. https://support.citrix.com/article/CTX234824 if needed
REM Install new VDA agent, delete files and scheduled tasks. Finally reboot.

C:\software\vdaupgrade\VDAServerSetup_1912.exe /masterpvsimage /virtualmachine /components VDA /controllers "DDC1 DDC2 DDC3" /noreboot /quiet /disableexperiencemetrics /enable_hdx_ports /enable_hdx_udp_ports /enable_real_time_transport /enable_remote_assistance
C:\Windows\system32\schtasks.exe /delete /tn VDAInstall /f
C:\Windows\system32\schtasks.exe /delete /tn VDAUninstall /f
del c:\software\vdaupgrade\remove.bat /F
del c:\software\vdaupgrade\VDAServerSetup_1912.exe /F
C:\Windows\System32\timeout.exe /t 5
C:\Windows\System32\shutdown.exe /r /t 20 /f
del c:\software\vdaupgrade\install.bat /F


Remove.bat
"C:\Program Files\Citrix\XenDesktopVdaSetup\XenDesktopVdaSetup.exe" /REMOVEALL /QUIET /NOREBOOT
C:\Windows\System32\shutdown.exe /r /t 5 /f