Automating the creation of a HDinsight cluster

Question

Hi,
I am trying to automate the creation of a HDinsight cluster using Azure Automation to execute a powershell script (the script from the automation gallery). When I try and run this (even without populating any defaults), it errors with the following error:
"Runbook definition is invalid. In a Windows PowerShell Workflow, parameter defaults may only be simple value types (such as integers) and strings. In addition, the type of the default value must match the type of the parameter."
The script I am trying to run is:
<#
 This PowerShell script was automatically converted to PowerShell Workflow so it can be run as a runbook.
 Specific changes that have been made are marked with a comment starting with “Converter:”
#>
<#
.SYNOPSIS
  Creates a cluster with specified configuration.
.DESCRIPTION
  Creates a HDInsight cluster configured with one storage account and default metastores. If storage account or container are not specified they are created
  automatically under the same name as the one provided for cluster. If ClusterSize is not specified it defaults to create small cluster with 2 nodes.
  User is prompted for credentials to use to provision the cluster.
  During the provisioning operation which usually takes around 15 minutes the script monitors status and reports when cluster is transitioning through the
  provisioning states.
.EXAMPLE
  .\New-HDInsightCluster.ps1 -Cluster "MyClusterName" -Location "North Europe"
  .\New-HDInsightCluster.ps1 -Cluster "MyClusterName" -Location "North Europe"  `
      -DefaultStorageAccount mystorage -DefaultStorageContainer myContainer `
      -ClusterSizeInNodes 4
#>
workflow New-HDInsightCluster99 {
 param (
     # Cluster dns name to create
     [Parameter(Mandatory = $true)]
     [String]$Cluster,
     # Location
     [Parameter(Mandatory = $true)]
     [String]$Location = "North Europe",
     # Blob storage account that new cluster will be connected to
     [Parameter(Mandatory = $false)]
     [String]$DefaultStorageAccount = "tavidon",
     # Blob storage container that new cluster will use by default
     [Parameter(Mandatory = $false)]
     [String]$DefaultStorageContainer = "patientdata",
     # Number of data nodes that will be provisioned in the new cluster
     [Parameter(Mandatory = $false)]
     [Int32]$ClusterSizeInNodes = 2,
     # Credentials to be used for the new cluster
     [Parameter(Mandatory = $false)]
     [PSCredential]$Credential = $null
 # Converter: Wrapping initial script in an InlineScript activity, and passing any parameters for use within the InlineScript
 # Converter: If you want this InlineScript to execute on another host rather than the Automation worker, simply add some combination of -PSComputerName, -PSCredential, -PSConnectionURI, or other workflow common parameters as parameters of
the InlineScript
 inlineScript {
  $Cluster = $using:Cluster
  $Location = $using:Location
  $DefaultStorageAccount = $using:DefaultStorageAccount
  $DefaultStorageContainer = $using:DefaultStorageContainer
  $ClusterSizeInNodes = $using:ClusterSizeInNodes
  $Credential = $using:Credential
  # The script has been tested on Powershell 3.0
  Set-StrictMode -Version 3
  # Following modifies the Write-Verbose behavior to turn the messages on globally for this session
  $VerbosePreference = "Continue"
  # Check if Windows Azure Powershell is avaiable
  if ((Get-Module -ListAvailable Azure) -eq $null)
      throw "Windows Azure Powershell not found! Please make sure to install them from 
  # Create storage account and container if not specified
  if ($DefaultStorageAccount -eq "") {
      $DefaultStorageAccount = $Cluster.ToLowerInvariant()
      # Check if account already exists then use it
      $storageAccount = Get-AzureStorageAccount -StorageAccountName $DefaultStorageAccount -ErrorAction SilentlyContinue
      if ($storageAccount -eq $null) {
          Write-Verbose "Creating new storage account $DefaultStorageAccount."
          $storageAccount = New-AzureStorageAccount –StorageAccountName $DefaultStorageAccount -Location $Location
      } else {
          Write-Verbose "Using existing storage account $DefaultStorageAccount."
  # Check if container already exists then use it
  if ($DefaultStorageContainer -eq "") {
      $storageContext = New-AzureStorageContext –StorageAccountName $DefaultStorageAccount -StorageAccountKey (Get-AzureStorageKey $DefaultStorageAccount).Primary
      $DefaultStorageContainer = $DefaultStorageAccount
      $storageContainer = Get-AzureStorageContainer -Name $DefaultStorageContainer -Context $storageContext -ErrorAction SilentlyContinue
      if ($storageContainer -eq $null) {
          Write-Verbose "Creating new storage container $DefaultStorageContainer."
          $storageContainer = New-AzureStorageContainer -Name $DefaultStorageContainer -Context $storageContext
      } else {
          Write-Verbose "Using existing storage container $DefaultStorageContainer."
  if ($Credential -eq $null) {
      # Get user credentials to use when provisioning the cluster.
      Write-Verbose "Prompt user for administrator credentials to use when provisioning the cluster."
      $Credential = Get-Credential
      Write-Verbose "Administrator credentials captured.  Use these credentials to login to the cluster when the script is complete."
  # Initiate cluster provisioning
  $storage = Get-AzureStorageAccount $DefaultStorageAccount
  New-AzureHDInsightCluster -Name $Cluster -Location $Location `
        -DefaultStorageAccountName ($storage.StorageAccountName + ".blob.core.windows.net") `
        -DefaultStorageAccountKey (Get-AzureStorageKey $DefaultStorageAccount).Primary `
        -DefaultStorageContainerName $DefaultStorageContainer `
        -Credential $Credential `
        -ClusterSizeInNodes $ClusterSizeInNodes
Many thanks
Brett

Answer 1

Hi,
it appears that [PSCredential]$Credential = $null is not correct, i to get the same
error, let me check further on it and revert back to you.
Best,
Amar