Compile DSC configurations in Azure Automation State Configuration

  • Article

You can compile Desired State Configuration (DSC) configurations in Azure Automation State Configuration in the following ways:

  • Azure State Configuration compilation service

    • Beginner method with interactive user interface
    • Easily track job state

  • Windows PowerShell

    • Call from Windows PowerShell on local workstation or build service
    • Integrate with development test pipeline
    • Provide complex parameter values
    • Work with node and non-node data at scale
    • Significant performance improvement

You can also use Azure Resource Manager templates with Azure Desired State Configuration (DSC) extension to push configurations to your Azure VMs. The Azure DSC extension uses the Azure VM Agent framework to deliver, enact, and report on DSC configurations running on Azure VMs. For compilation details using Azure Resource Manager templates, see Desired State Configuration extension with Azure Resource Manager templates.

Compile a DSC configuration in Azure State Configuration

Portal

  1. In your Automation account, click State configuration (DSC).
  2. Click on the Configurations tab, then click on the configuration name to compile.
  3. Click Compile.
  4. If the configuration has no parameters, you're prompted to confirm if you want to compile it. If the configuration has parameters, the Compile Configuration blade opens so that you can provide parameter values.
  5. The Compilation Job page is opened so that you can track compilation job status. You can also use this page to track the node configurations (MOF configuration documents) placed on the Azure Automation State Configuration pull server.

Azure PowerShell

You can use Start-AzAutomationDscCompilationJob to start compiling with Windows PowerShell. The following sample code begins compilation of a DSC configuration called SampleConfig.

Start-AzAutomationDscCompilationJob -ResourceGroupName 'MyResourceGroup' -AutomationAccountName 'MyAutomationAccount' -ConfigurationName 'SampleConfig'

Start-AzAutomationDscCompilationJob returns a compilation job object that you can use to track job status. You can then use this compilation job object with Get-AzAutomationDscCompilationJob to determine the status of the compilation job, and Get-AzAutomationDscCompilationJobOutput to view its streams (output). The following sample starts compilation of the SampleConfig configuration, waits until it has completed, and then displays its streams.

$CompilationJob = Start-AzAutomationDscCompilationJob -ResourceGroupName 'MyResourceGroup' -AutomationAccountName 'MyAutomationAccount' -ConfigurationName 'SampleConfig'

while($null -eq $CompilationJob.EndTime -and $null -eq $CompilationJob.Exception)
{
    $CompilationJob = $CompilationJob | Get-AzAutomationDscCompilationJob
    Start-Sleep -Seconds 3
}

$CompilationJob | Get-AzAutomationDscCompilationJobOutput -Stream Any

Declare basic parameters

Parameter declaration in DSC configurations, including parameter types and properties, works the same as in Azure Automation runbooks. See Starting a runbook in Azure Automation to learn more about runbook parameters.

The following example uses FeatureName and IsPresent parameters to determine the values of properties in the ParametersExample.sample node configuration, generated during compilation.

Configuration ParametersExample
{
    param(
        [Parameter(Mandatory=$true)]
        [string] $FeatureName,

        [Parameter(Mandatory=$true)]
        [boolean] $IsPresent
    )

    $EnsureString = 'Present'
    if($IsPresent -eq $false)
    {
        $EnsureString = 'Absent'
    }

    Node 'sample'
    {
        WindowsFeature ($FeatureName + 'Feature')
        {
            Ensure = $EnsureString
            Name   = $FeatureName
        }
    }
}

You can compile DSC configurations that use basic parameters in the Azure Automation State Configuration portal or with Azure PowerShell.

Portal

In the portal, you can enter parameter values after clicking Compile.

Configuration compile parameters

Azure PowerShell

PowerShell requires parameters in a hashtable, where the key matches the parameter name and the value equals the parameter value.

$Parameters = @{
    'FeatureName' = 'Web-Server'
    'IsPresent' = $False
}

Start-AzAutomationDscCompilationJob -ResourceGroupName 'MyResourceGroup' -AutomationAccountName 'MyAutomationAccount' -ConfigurationName 'ParametersExample' -Parameters $Parameters

For information about passing PSCredential objects as parameters, see Credential assets.

Compile configurations containing composite resources in Azure Automation

The Composite Resources feature allows you to use DSC configurations as nested resources inside a configuration. This feature enables the application of multiple configurations to a single resource. See Composite resources: Using a DSC configuration as a resource to learn more about composite resources.

Note

So that configurations containing composite resources compile correctly, you must first import into Azure Automation any DSC resources that the composites rely upon. Adding a DSC composite resource is no different from adding any PowerShell module to Azure Automation. This process is documented in Manage Modules in Azure Automation.

Manage ConfigurationData when compiling configurations in Azure Automation

ConfigurationData is a built-in DSC parameter that allows you to separate structural configuration from any environment-specific configuration while using PowerShell DSC. For more information, see Separating "What" from "Where" in PowerShell DSC.

Note

When compiling in Azure Automation State Configuration, you can use ConfigurationData in Azure PowerShell but not in the Azure portal.

The following example DSC configuration uses ConfigurationData via the $ConfigurationData and $AllNodes keywords. You also need the xWebAdministration module for this example.

Configuration ConfigurationDataSample
{
    Import-DscResource -ModuleName xWebAdministration -Name MSFT_xWebsite

    Write-Verbose $ConfigurationData.NonNodeData.SomeMessage

    Node $AllNodes.Where{$_.Role -eq 'WebServer'}.NodeName
    {
        xWebsite Site
        {
            Name         = $Node.SiteName
            PhysicalPath = $Node.SiteContents
            Ensure       = 'Present'
        }
    }
}

You can compile the preceding DSC configuration with Windows PowerShell. The following script adds two node configurations to the Azure Automation State Configuration pull service: ConfigurationDataSample.MyVM1 and ConfigurationDataSample.MyVM3.

$ConfigData = @{
    AllNodes = @(
        @{
            NodeName = 'MyVM1'
            Role = 'WebServer'
        },
        @{
            NodeName = 'MyVM2'
            Role = 'SQLServer'
        },
        @{
            NodeName = 'MyVM3'
            Role = 'WebServer'
        }
    )

    NonNodeData = @{
        SomeMessage = 'I love Azure Automation State Configuration and DSC!'
    }
}

Start-AzAutomationDscCompilationJob -ResourceGroupName 'MyResourceGroup' -AutomationAccountName 'MyAutomationAccount' -ConfigurationName 'ConfigurationDataSample' -ConfigurationData $ConfigData

Work with assets in Azure Automation during compilation

Asset references are the same in both Azure Automation State Configuration and runbooks. For more information, see the following:

Credential assets

DSC configurations in Azure Automation can reference Automation credential assets using the Get-AutomationPSCredential cmdlet. If a configuration has a parameter that specifies a PSCredential object, use Get-AutomationPSCredential by passing the string name of an Azure Automation credential asset to the cmdlet to retrieve the credential. Then make use of that object for the parameter requiring the PSCredential object. Behind the scenes, the Azure Automation credential asset with that name is retrieved and passed to the configuration. The example below shows this scenario in action.

Keeping credentials secure in node configurations (MOF configuration documents) requires encrypting the credentials in the node configuration MOF file. Currently you must give PowerShell DSC permission to output credentials in plain text during node configuration MOF generation. PowerShell DSC is not aware that Azure Automation encrypts the entire MOF file after its generation through a compilation job.

You can tell PowerShell DSC that it is okay for credentials to be outputted in plain text in the generated node configuration MOFs using configuration Data. You should pass PSDscAllowPlainTextPassword = $true via ConfigurationData for each node block name that appears in the DSC configuration and uses credentials.

The following example shows a DSC configuration that uses an Automation credential asset.

Configuration CredentialSample
{
    Import-DscResource -ModuleName PSDesiredStateConfiguration
    $Cred = Get-AutomationPSCredential 'SomeCredentialAsset'

    Node $AllNodes.NodeName
    {
        File ExampleFile
        {
            SourcePath      = '\\Server\share\path\file.ext'
            DestinationPath = 'C:\destinationPath'
            Credential      = $Cred
        }
    }
}

You can compile the preceding DSC configuration with PowerShell. The following PowerShell code adds two node configurations to the Azure Automation State Configuration pull server: CredentialSample.MyVM1 and CredentialSample.MyVM2.

$ConfigData = @{
    AllNodes = @(
        @{
            NodeName = '*'
            PSDscAllowPlainTextPassword = $True
        },
        @{
            NodeName = 'MyVM1'
        },
        @{
            NodeName = 'MyVM2'
        }
    )
}

Start-AzAutomationDscCompilationJob -ResourceGroupName 'MyResourceGroup' -AutomationAccountName 'MyAutomationAccount' -ConfigurationName 'CredentialSample' -ConfigurationData $ConfigData

Note

When compilation is complete, you might receive the error message The 'Microsoft.PowerShell.Management' module was not imported because the 'Microsoft.PowerShell.Management' snap-in was already imported. You can safely ignore this message.

Compile your DSC configuration in Windows PowerShell

The process to compile DSC configurations in Windows PowerShell is included in the PowerShell DSC documentation Write, Compile, and Apply a Configuration. You can execute this process from a developer workstation or within a build service, such as Azure DevOps. You can then import the MOF files produced by compiling the configuration into the Azure State Configuration service.

Compiling in Windows PowerShell also provides the option to sign configuration content. The DSC agent verifies a signed node configuration locally on a managed node. Verification ensures that the configuration applied to the node comes from an authorized source.

You can also import node configurations (MOF files) that have been compiled outside of Azure. The import includes compilation from a developer workstation or in a service such as Azure DevOps. This approach has multiple advantages, including performance and reliability.

Note

A node configuration file must be no larger than 1 MB to allow Azure Automation to import it.

For more information about signing of node configurations, see Improvements in WMF 5.1 - How to sign configuration and module.

Import a node configuration in the Azure portal

  1. In your Automation account, click State configuration (DSC) under Configuration Management.

  2. On the State configuration (DSC) page, click on the Configurations tab, then click Add.

  3. On the Import page, click the folder icon next to the Node Configuration File field to browse for a node configuration MOF file on your local computer.

    Browse for local file

  4. Enter a name in the Configuration Name field. This name must match the name of the configuration from which the node configuration was compiled.

  5. Click OK.

Import a node configuration with Azure PowerShell

You can use the Import-AzAutomationDscNodeConfiguration cmdlet to import a node configuration into your Automation account.

Import-AzAutomationDscNodeConfiguration -AutomationAccountName 'MyAutomationAccount' -ResourceGroupName 'MyResourceGroup' -ConfigurationName 'MyNodeConfiguration' -Path 'C:\MyConfigurations\TestVM1.mof'

Next steps