Unable to find type [CloudFileDirectory] error - dependent assemblies in a custom Azure DSC module

Question

I have created a custom module as a PowerShell class following, roughly, the instructions available at Writing a custom DSC resource with PowerShell classes. The intent is to connect to Azure File Storage and download some files. I am using Azure Automation DSC as my pull server.

Let me start by saying that, when run through the PowerShell ISE, the code works a treat. Something goes wrong when I upload it to Azure though - I get the error Unable to find type [CloudFileDirectory]. This type specifier comes from assemblies referenced in through the module Azure.Storage which is definitely in my list of automation assets.

At the tippy top of my psm1 file I have

Using namespace Microsoft.WindowsAzure.Storage.File

[DscResource()]
class tAzureStorageFileSync
{
    ...
    # Create the search context
    [CloudFileDirectory] GetBlobRoot()
    {
        ...
    }
    ...
}

I'm not sure whether this Using is supported in this scenario or not, so let's call that Question 1

To date I have tried:

Adding RequiredModules = @( "Azure.Storage" ) to the psd1 file
Adding RequiredAssemblies = @( "Microsoft.WindowsAzure.Storage.dll" ) to the psd1 file
Shipping the actual Microsoft.WindowsAzure.Storage.dll file in the root of the module zip that I upload (that has a terrible smell about it)

When I deploy the module to Azure with New-AzureRmAutomationModule it uploads and processes just fine. The Extracting activities... step works and gives no errors.

When I compile a configuration, however, the compilation process fails with the Unable to find type error I mentioned.

I have contemplated adding an Import-Module Azure.Storage above the class declaration, but I've never seen that done anywhere else before.

Question 2 Is there a way I can compile locally using a similar process to the one used by Azure DSC so I can test changes more quickly?

Question 3 Does anyone know what is going wrong here?

restless1987 restless1987 · Accepted Answer · 2016-11-02T10:25:29

Question 1/3: If you create classes in powershell and use other classes within, ensure that these classes are present BEFORE loading the scriptfile that contains your new class.

I.e.: Loader.ps1:

Import-Module Azure.Storage
. .\MyDSC-Class.ps1

Powershell checks if it finds all types you refer while interpreting the script, so all types must be loaded before that happens. You can do this by creating a scriptfile that loads all dependencies first and loads your script after that.

Unable to find type [CloudFileDirectory] error - dependent assemblies in a custom Azure DSC module

3 Answers