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Validate operating system information in a configuration

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This example shows how you can use the Microsoft/OSInfo resource to assert that a configuration document applies to a specific operating system.

Important

The osinfo command and Microsoft/OSInfo resource are a proof-of-concept example for use with DSCv3. Don't use it in production.

Definition

The configuration document defines a resource group called Operating System Assertion with an instance of the Microsoft/OSInfo resource.

The resource group uses the DSC/AssertionGroup resource to ensure that the test method is called for every instance in the group, regardless of the actual configuration operation being applied. When DSC processes the resource group, it calls the test operation for the nested instances instead of the get and set operations. Instances in the group never change the state of the system.

The instance of the Microsoft/OSInfo resource defines the bitness property to validate that the configuration is applied on a 64-bit operating system.

# yaml-language-server: $schema=https://raw.githubusercontent.com/PowerShell/DSC/main/schemas/2023/08/config/document.json
$schema: https://raw.githubusercontent.com/PowerShell/DSC/main/schemas/2023/08/config/document.json
resources:
  - name: Operating System Assertion
    type: DSC/AssertionGroup
    properties:
      $schema: https://raw.githubusercontent.com/PowerShell/DSC/main/schemas/2023/08/config/document.json
      resources:
        - name: Is64BitOS
          type: Microsoft/OSInfo
          properties:
            bitness: '64'

Getting the current state

To get the current state of the instances in the configuration document, pass the contents of the document to the dsc config get command.

configuration=$(cat ./osinfo.config.dsc.yaml)
echo configuration | dsc config get

The output depends on whether the operating system is 32-bit or 64-bit.

Applied to a 32-bit Linux operating system, the get result shows that the Is64BitOS instance is out of the desired state because the bitness property is 32.

results:
- name: Operating System Assertion
  type: DSC/AssertionGroup
  result:
    actualState:
      results:
      - name: Is64BitOS
        type: Microsoft/OSInfo
        result:
          desiredState:
            bitness: '64'
          actualState:
            $id: https://developer.microsoft.com/json-schemas/dsc/os_info/20230303/Microsoft.Dsc.OS_Info.schema.json
            family: Linux
            version: '20.04'
            codename: focal
            bitness: '32'
            architecture: i386
          inDesiredState: false
          differingProperties:
          - bitness
      messages: []
      hadErrors: false
messages: []
hadErrors: false

Enforcing the desired state

To enforce the desired state of the instances in the configuration document, pass the contents of the document to the dsc config set command.

echo configuration | dsc config set

The output depends on whether the operating system is 32-bit or 64-bit. In all cases, the changedProperties field for the result is an empty list. The DSC/AssertionGroup resource group never changes system state and the Microsoft/OSInfo resource doesn't implement the set operation.

results:
- name: Operating System Assertion
  type: DSC/AssertionGroup
  result:
    beforeState:
      results:
      - name: Is64BitOS
        type: Microsoft/OSInfo
        result:
          desiredState:
            bitness: '64'
          actualState:
            $id: https://developer.microsoft.com/json-schemas/dsc/os_info/20230303/Microsoft.Dsc.OS_Info.schema.json
            family: Linux
            version: '20.04'
            codename: focal
            bitness: '32'
            architecture: i386
          inDesiredState: false
          differingProperties:
          - bitness
      messages: []
      hadErrors: false
    afterState:
      results:
      - name: Is64BitOS
        type: Microsoft/OSInfo
        result:
          desiredState:
            bitness: '64'
          actualState:
            $id: https://developer.microsoft.com/json-schemas/dsc/os_info/20230303/Microsoft.Dsc.OS_Info.schema.json
            family: Linux
            version: '20.04'
            codename: focal
            bitness: '32'
            architecture: i386
          inDesiredState: false
          differingProperties:
          - bitness
      messages: []
      hadErrors: false
    changedProperties: []
messages: []
hadErrors: false