Assigning Gateways and Agents to Management Servers using PowerShell

########### Gateway Stuff

# Get a specific gateway server object by name
$Gateway = Get-SCOMManagementServer | where {$_.Name –eq "dmzscomagw1.dmz.net"}

# Show the gateway server assignments for primary and failover
$Gateway.GetPrimaryManagementServer().DisplayName
$Gateway.GetFailoverManagementServers().DisplayName

# Gateway set parent Examples
$Primary = Get-SCOMManagementServer | where {$_.Name –eq "scom1.opsmgr.net"} 
$Failover = Get-SCOMManagementServer | where {$_.Name –eq "scom2.opsmgr.net"}
$FailoverList = Get-SCOMManagementServer | where {$_.Name –ne "scom1.opsmgr.net" -and $_.IsGateway -eq $false}

# Set the gateway server to a specific primary
Set-SCOMParentManagementServer -GatewayServer $Gateway -PrimaryServer $Primary

# Set the gateway server to a specific failover
Set-SCOMParentManagementServer -GatewayServer $Gateway -FailoverServer $Failover

# Set the gateway server to a list of management servers for failover
Set-SCOMParentManagementServer -GatewayServer $Gateway -FailoverServer $FailoverList

# Set the gateway server failover to empty
Set-SCOMParentManagementServer -GatewayServer $Gateway -FailoverServer $null

# End

########### Agent Stuff

# Get Management Server Object Examples
$Primary = Get-SCOMManagementServer | where {$_.Name –eq "scom1.opsmgr.net"} 
$Failover = Get-SCOMManagementServer | where {$_.Name –eq "scom2.opsmgr.net"}
$FailoverList = Get-SCOMManagementServer | where {$_.Name –ne "scoma1.opsmgr.net" -and $_.IsGateway -eq $false}

# Get a specific agent by name
$Agent = Get-SCOMAgent -DNSHostName 'server.opsmgr.net'

# Get all agents currently assigned to a management server or GW
$Agents = Get-SCOMAgent -ManagementServer $Primary

# Get parent assignments for an agent
$Agent.GetPrimaryManagementServer().DisplayName
$Agent.GetFailoverManagementServers().DisplayName

# Agent set parent Examples
Set-SCOMParentManagementServer -Agent $Agent -PrimaryServer: $Primary
Set-SCOMParentManagementServer -Agent $Agent -PrimaryServer: $Gateway
Set-SCOMParentManagementServer -Agent $Agent -FailoverServer $Failover
Set-SCOMParentManagementServer -Agent $Agent -FailoverServer $FailoverList

# Reassigning all agents in an array of agents
FOREACH ($Agent in $Agents)
{
  [string]$AgentName = $Agent.DisplayName
  Write-Host "`nStarting agent assignment for ($AgentName)"
  $PriBefore = $Agent.GetPrimaryManagementServer().DisplayName
  $FailBefore = $Agent.GetFailoverManagementServers().DisplayName
  Write-Host "Primary before assignment for ($AgentName) is ($PriBefore)"
  Write-Host "Failover before assignment for ($AgentName) is ($FailBefore)"
  IF ($FailBefore)
  {
    # We need to remove any failover settings for this agent in case we are setting a primary server already in the failover list
    Write-Host "Removing Failover...."
    Set-SCOMParentManagementServer -Agent $Agent -FailoverServer $null
  }
  Write-Host "Assigning...."
  Set-SCOMParentManagementServer -Agent $Agent -PrimaryServer: $Primary
  Set-SCOMParentManagementServer -Agent $Agent -FailoverServer $Failover  
  $PriAfter = $Agent.GetPrimaryManagementServer().DisplayName
  $FailAfter = $Agent.GetFailoverManagementServers().DisplayName
  Write-Host "Primary before assignment for ($AgentName) is ($PriAfter)"
  Write-Host "Failover before assignment for ($AgentName) is ($FailAfter)"
}

# End