MSI Installer

installcheck.ps1

# TODO: change variable expansion method for newer approach ({0}, etc.)

# Exitcodes ($lastexitcode)
#  0: Success
#  1: MSI doesn't exist
#  2: Not our first time
#  All other codes (=>13): see https://docs.microsoft.com/en-us/windows/win32/msi/error-codes

# Vars
$workingdir = "C:\\working"
$touchFile = "do_not_retry_LAPS.touch"
$installer = "LAPS.x64.msi"
$childNametoCheck = "{EA8CB806-C109-4700-96B4-F1F268E5036C}"
# Child Names will either be GUID (MSFT standard), or equivalent to DisplayName
# LAPS Identifiying Number
# {EA8CB806-C109-4700-96B4-F1F268E5036C}

function ExitWithCode
{
    param($exitcode)
    $host.SetShouldExit($exitcode)
    exit $exitcode
}

function Get-InstalledPrograms-ChildName()
{
    $regLocations = (
        "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\", 
        "HKCU:\Software\Microsoft\Windows\CurrentVersion\Uninstall\",
        "HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\"
        )

    Get-ChildItem ($regLocations | Where { Test-Path $_ } ) |
        Get-ItemProperty |
        Where {
            ( (Get-Member -InputObject $_ -Name DisplayName) -and $_.DisplayName -ne $Null) -and
            (!(Get-Member -InputObject $_ -Name SystemComponent) -or $_.SystemComponent -ne "1") -and 
            (!(Get-Member -InputObject $_ -Name ParentKeyName) -or $_.ParentKeyName -eq $Null)
            } |
        Select PSChildName
}

# Step 1: Get Working directory in order
New-Item -Path $workingdir -ItemType Directory -ErrorAction SilentlyContinue

if ( -not (Test-Path "$workingdir\$installer" -PathType Leaf) ) {
    Write-Host "MSI $installer does not exist in working directory $workingdir.  Failing script."
    ExitWithCode -exitcode 1
}

# Step 2: Check conditions to allow MSI install
# 1. MSI must not be installed
# 2. This must be our first attempt, evidenced by stop file in $
#
# NB: We are deliberately NOT using Get-WmiObject Win32_Product because it may modify the Guest OS if it finds errors
# within the installer database.  Avoiding this by looking to Uninstall registry keys.

if ( @(Get-InstalledPrograms-ChildName | Where-Object { $_.PSChildName -eq $childNametoCheck }).Count -ge 1) {
    Write-Host "Package found, ignore"
    ExitWithCode -exitcode 0
} else {
    if ( -not (Test-Path "$workingdir\$touchFile" -PathType Leaf) ) {
        # Step 3: Install MSI
        Write-Host "Package not found, and this is our first time installing.  Proceeding with install"

        $DataStamp = Get-Date -Format yyyyMMddTHHmmss
        $logFile = "$workingdir\$installer-$DataStamp.log"
        $MSIArguments = @("/i", ("$workingdir\$installer"), "/qn", "/norestart", "/L*v", $logFile)

        # Create touch file so we never can run this branch again
        Out-File -FilePath "$workingdir\$touchFile"

        # Start installation
        $status = (Start-Process "msiexec.exe" -ArgumentList $MSIArguments -Wait -NoNewWindow -Passthru).ExitCode

        if ($status -ge 1) {
            Write-Host "MSI install failed"
        } else {
            Write-Host "MSI passed 0 - success"
        }

        # Pass exit code back
        ExitWithCode -exitcode $status

    } else {
        Write-Host "Package not found, and this is NOT our first time.  Failing."
        ExitWithCode -exitcode 2
    }
}

Write-Host "We should not reach here."
ExitWithCode -exitcode 127