Preferred.ps1

function Set-ClusterVMPreferredOwner {
  <#
      .SYNOPSIS
      Will configure Preferred Owners for Virtual Machine running on Failover Cluster
  
      .DESCRIPTION
      Uses Invoke-Command to allow for PSCredential
      If Preferred Owner is provided will verify if it matches cluster Owner Nodes. 
      If yes - will set Preferred Owners for given VMs.
      If no - will abort.
      If $null, or '' is provided will reset Preferred Owners to defaults for given VM
  
      .PARAMETER Cluster
      Cluster Name
  
      .PARAMETER Credential
      Optional PSCredential used to connect to cluster
  
      .PARAMETER VMName
      Virtual Machine Name or array of names to process
  
      .PARAMETER PreferredOwner
      Preferred Owner to set for given VM
  
      .EXAMPLE
      Set-ClusterVMPreferredOwner -Cluster 'Cluster' -VMName 'VM1' -PreferredOwner 'Node1' -Verbose
      Will set Preferred Owner on VM1 to Node1
  
      VERBOSE: Processing with default credentials of user {mczerniawski_admin}
      VERBOSE: Given preferred owner {Node1} was found in nodes of cluster {Cluster}
      VERBOSE: Processing VM {VM1}
      VERBOSE: VM {VM1} current preferred owner: {}
      VERBOSE: Setting preferred owner: {Node1} for VM {VM1} 
      VERBOSE: VM {VM1} current preferred owner: {Node1}
  
      .EXAMPLE
      Set-ClusterVMPreferredOwner -Cluster 'Cluster' -VMName 'VM1','VM2' -Credential (Get-Credential) -Verbose
      Will set Preferred Owner on VM1 to Node1
  
      VERBOSE: Processing with provided credentials {contoso\mczerniawski_admin}
      VERBOSE: Provided no Preferred Owner. Will reset to default setting
      VERBOSE: Processing VM {VM1}
      VERBOSE: VM {VM1} current preferred owner: {Node1}
      VERBOSE: Setting preferred owner: {} for VM {VM1} 
      VERBOSE: VM {VM1} current preferred owner: {}
      VERBOSE: Processing VM {VM2}
      VERBOSE: VM {VM2} current preferred owner: {}
      VERBOSE: Setting preferred owner: {} for VM {VM2} 
      VERBOSE: VM {VM2} current preferred owner: {}
  
  #>
  
  
  
  [CmdletBinding()]
  param(
    [Parameter(Mandatory, HelpMessage = 'Provide Cluster Name',
    ValueFromPipeline, ValueFromPipelineByPropertyName)]
    [ValidateNotNullOrEmpty()]
    [System.String]
    $Cluster,
  
    [Parameter(Mandatory = $false, HelpMessage = 'Provide Credentials for Cluster',
    ValueFromPipeline, ValueFromPipelineByPropertyName)]
    [System.Management.Automation.PSCredential]
    $Credential,
  
    [Parameter(Mandatory, HelpMessage = 'Provide VMName',
    ValueFromPipeline, ValueFromPipelineByPropertyName)]
    [ValidateNotNullOrEmpty()]
    [System.String[]]
    $VMName,
  
    [Parameter(Mandatory = $false, HelpMessage = 'Provide Preferred Owners Nodes to restrict VM to failover to',
    ValueFromPipeline,ValueFromPipelineByPropertyName)]
    [System.String[]]
    $PreferredOwner
  )
  begin {
    #region PSSession parameters
    $connectionParams = @{
      ComputerName = $Cluster
    }
    if ($PSBoundParameters.ContainsKey('Credential')) {
      $connectionParams.Credential = $Credential
      Write-Verbose -Message "Processing with provided credentials {$($Credential.UserName)}"
    }
    else {
      Write-Verbose -Message "Processing with default credentials of user {$($env:USERNAME)}"
    }
    $ClusterSession = New-PSSession @connectionParams -ErrorAction Stop
    #endregion 
       
    #region Validate Preferred Owner
    $nodesInCluster = Invoke-Command -Session $ClusterSession -ScriptBlock {
      Get-ClusterNode | Select-Object -ExpandProperty Name
    }
    #null or empty string - reset to defaults
    if (-not $PreferredOwner) {
      Write-Verbose -Message "Provided no Preferred Owner. Will reset to default setting"
      $PreferredOwner = ''
    }
    #check if given hosts given in $PreferredOwner are members of $Cluster
    else {
      switch (Compare-Object -ReferenceObject @($nodesInCluster) -DifferenceObject @($PreferredOwner) -IncludeEqual ) {
        {$PSItem.SideIndicator -eq '=>'} {
          Write-Error -Message "Given preferred owner {$($PSItem.InputObject)} not found in nodes of cluster {$Cluster}. Aborting" -ErrorAction Stop
          break
        }
        {$PSItem.SideIndicator -eq '=='} {
          Write-Verbose -Message "Given preferred owner {$($PSItem.InputObject)} was found in nodes of cluster {$Cluster}" 
        }
  
      }
    }
    #endregion
  }
  process {
    foreach ($VM in $VMName) {
      Write-Verbose -Message "Processing VM {$VM}"
      $ClusterVM = Invoke-Command -Session $ClusterSession  -ScriptBlock {
        Get-ClusterGroup -Name $USING:VM -ErrorAction SilentlyContinue | Select-Object *
      }
      if (-not $ClusterVM) { 
        Write-Error -Message "VM {$VM} not found on cluster {$Cluster}"
      }
      else {
        $currentPreferredOwners = Invoke-Command -Session $ClusterSession  -ScriptBlock {
          Get-ClusterGroup -Name $USING:VM | Get-ClusterOwnerNode | Select-Object -ExpandProperty OwnerNodes
        }
        Write-Verbose -Message "VM {$VM} current preferred owner: {$($currentPreferredOwners -join ',')}"
        Write-Verbose -Message "Setting preferred owner: {$($PreferredOwner -join ',')} for VM {$VM} "
        Invoke-Command -Session $ClusterSession  -ScriptBlock {
          Get-ClusterGroup -Name $USING:VM | Set-ClusterOwnerNode -Owners $USING:PreferredOwner
        }
        $currentPreferredOwners = Invoke-Command -Session $ClusterSession  -ScriptBlock {
          Get-ClusterGroup -Name $USING:VM | Get-ClusterOwnerNode | Select-Object -ExpandProperty OwnerNodes
        }
        Write-Verbose -Message "VM {$VM} current preferred owner: {$($currentPreferredOwners -join ',')}"
      }
    }
  }
  end {
    $ClusterSession | Remove-PSSession -ErrorAction SilentlyContinue
  }
}