script to pre-stage AD server and add to required groups

New-OPSWindowsServer.ps1

[CmdletBinding()]
param (
    [Parameter(Mandatory)]
    [string]
    $ComputerName, 

    # Parameter help description
    [Parameter()]
    [string]
    $OUPath = 'OU=Windows,OU=Servers,DC=mydomain,DC=local',

    # Parameter help description
    [Parameter(Mandatory)]
    [PSCredential]
    $Credential,

    # Parameter help description
    [Parameter(Mandatory)]
    [string]
    $Description,

    # Parameter help description
    [Parameter(Mandatory)]
    [ValidateSet('Pilot', 'Inner', 'Outer', 'Picking A', 'Picking B', 'Plant Overnight', 'Default')]
    [string]
    $PatchingRing
)

# check for the Active Directory PowerShell Module
if ($null -eq (Get-Module -Name ActiveDirectory -ListAvailable)) {
    Write-Warning 'Active Directory Module not found.'
    Write-Warning 'Exiting.'
    Start-Sleep -Seconds 2
    Exit
}

# Get a domain controller
$DC = Get-ADDomainController -DomainName mydomain.local -SiteName Ridge -Discover | Select-Object -ExpandProperty Name
# flip the parameter to the group name
switch ($PatchingRing) {
    'Pilot' { $WSUSGroup = 'WSUS Servers Pilot Ring' }
    'Inner' { $WSUSGroup = 'WSUS Servers Inner Ring' }
    'Outer' { $WSUSGroup = 'WSUS Servers Outer Ring' }
    'Picking A' { $WSUSGroup = 'WSUS Servers Picking A' }
    'Picking B' { $WSUSGroup = 'WSUS Servers Picking B' }
    'Plant Overnight' { $WSUSGroup = 'WSUS Servers Plant Overnight' }
    'Default' { $WSUSGroup = '' }
}

# Relevant information for groups that need to be created
$GroupsOU = 'OU=Local Groups,OU=Servers,OU=Groups,DC=mydomain,DC=local'
$GroupsToCreate = "SERVER_$ComputerName Local Admins", "SERVER_$ComputerName Remote Desktop Users"

try {
    # check to see if the computer already exists
    Get-ADComputer -Identity $ComputerName -ErrorAction Stop -Server $DC

    # if no error, write warning
    Write-Warning 'A computer with this name already exists'
} catch {
    # it does not already exist, let's create it
    try {
        $NewComputerParams = @{
            Name           = $ComputerName
            SAMAccountName = $ComputerName
            Path           = $OUPath
            Description    = $Description
            Enabled        = $False
            Credential     = $Credential
            Server         = $DC
            ErrorAction    = 'Stop'
        }
        # try to create the new server
        New-ADComputer @NewComputerParams
        
        # let's add it to a WSUS Group if necessary
        if ($WSUSGroup -ne '') {
            $WSUSGroupParams = @{
                Identity    = $WSUSGroup
                Members     = Get-ADComputer -Identity $ComputerName | Select-Object -ExpandProperty DistinguishedName
                Server      = $DC
                Credential  = $Credential
                ErrorAction = 'Stop'
            }
            Add-ADGroupMember @WSUSGroupParams
        } 
        
        catch {
            $TheError = $_ 
            # do something here - could not create the new computer -OR- add to the WSUS rings
            Write-Warning "Error creating computer: $ComputerName -OR- adding to group: $WSUSGroup"
        }
    
        # now we need to create some AD groups to manage local admins and RDP users
        
        # do the groups already exist?
        foreach ($group in $GroupsToCreate) {
            try {
                Get-ADGroup -Identity $group -Server $DC -ErrorAction Stop  
                Write-Warning "$Group already exists"
            } catch {
                if ($group -match 'Administrators') {
                    $GroupDescription = "This group is a member of the local administrators group on $ComputerName"
                } else {
                    $GroupDescription = "This group is a member of the local remote desktop users group on $ComputerName"
                }
                # create the new group
                $NewGroupParams = @{
                    Name           = $group
                    SAMAccountName = $group
                    DisplayName    = $group
                    Path           = $GroupsOU
                    GroupCategory  = 'Security'
                    GroupScope     = 'Global'
                    Description    = $GroupDescription
                    Server         = $DC
                    Credential     = $Credential
                    ErrorAction    = 'Stop'
                }
                New-ADGroup @NewGroupParams
            }
        }
    } catch {
        $TheError = $_ 
        # do something here - creating the new 
        Write-Warning 'Error 4'
    }
}