Dynamic grouping of machines based on "Managed by" Active Directory Attribute

Solution 1:

After some research I found that someone already tackled this problem. Sort of. I modified this script. Got rid of the last couple of lines and added the logic below I needed. It is messy but it works like a charm. All you need to change is the management server and the inclusion regex (we have multiple domains but only want this sort of automation for one).

<Functions from original script go here>

$ManagementServer = "<ManagementServerGoesHere>"

$ManagementGroup = GetSCOMManagementGroup -ms $ManagementServer
$Groups = Get-SCOMGroup -DisplayName "Managed-By *"
$Groups |% {
    $Group = $_
    $Group.DisplayName -match "Managed-By (\w{3})" | Out-Null
    $sAMAccountName = $Matches[1]
    $User = Get-ADUser -Filter {sAMAccountName -eq $sAMAccountName}
    $UserDN = $User.DistinguishedName
    $ADManagedByComputers = Get-ADComputer -Filter {ManagedBy -eq $UserDN}
    $SCOMManagedByComputer = Get-SCOMGroup $Group.id | Get-SCOMClassInstance
    [string]$InstancesToAdd = ""
    [string]$InstancesToRemove = ""

    $ADManagedByComputers | % {
        if($SCOMManagedByComputer.DisplayName -notcontains $_.DNSHostName) {
            $Agent = Get-SCOMAgent -DNSHostName $_.DNSHostName
            if($Agent) {
                Write-Host ($_.DNSHostName + " not in SCOM Group " + $Group.DisplayName) -ForegroundColor Yellow
                $InstancesToAdd = $InstancesToAdd + "," + $Agent.Id
             } else {
                Write-Host ($_.DNSHostName + " has no Agent installed!") -ForegroundColor Gray
             }
        } else {
            Write-Host ($_.DNSHostname + " already in SCOM Group " + $Group.DisplayName) -ForegroundColor Green
        }
    }

    $SCOMManagedByComputer | % {
        if($_.DisplayName -match "<InclusionRegex>") {
            if($ADManagedByComputers.DNSHostName -notcontains $_.DisplayName) {
                Write-Host ($_.DisplayName + " should not be in SCOM Group " + $Group.DisplayName) -ForegroundColor DarkYellow
                $Agent = Get-SCOMAgent -DNSHostName $_.DisplayName
                if($Agent) {
                    $InstancesToRemove = $InstancesToRemove + "," + $Agent.Id
                }
            }  
        } else {
            Write-Host ($_.DisplayName + " is not in the domain scope. Skipping.") -ForegroundColor Cyan
        }
    }

    $InstancesToAdd = $InstancesToAdd.Trim(",")
    $InstancesToRemove = $InstancesToRemove.Trim(",")


        $ManagementPackName = ($Group | Get-SCOMClass).ManagementPackName
        $ManagementPackID = (Get-SCManagementPack -Name $ManagementPackName)
        $MP = ValidateGroup -mg $ManagementGroup -mp $MP -groupID $Group.FullName
    If($InstancesToAdd -ne "" -and $InstancesToRemove -ne "") {
        $MP = UpdateGroup -mg $ManagementGroup -mp $ManagementPackID -groupID $Group.FullName -instancesToAdd $InstancesToAdd -instancesToRemove $InstancesToRemove
    }

    if($InstancesToAdd -ne "" -and $InstancesToRemove -eq "") {
        $MP = UpdateGroup -mg $ManagementGroup -mp $MP -groupID $Group.FullName -instancesToAdd $InstancesToAdd
    }

    if($InstancesToAdd -eq "" -and $InstancesToRemove -ne "") {
        $MP = UpdateGroup -mg $ManagementGroup -mp $MP -groupID $Group.FullName -instancesToRemove $InstancesToRemove
    }
}