What is desired state configuration

Desired State Configuration (DSC) is a configuration management tool in PowerShell used to declaratively specify how a system should be configured. DSC enables administrators to automate the process of setting up and maintaining the desired configuration of servers and other infrastructure components.

With DSC, administrators can define the desired state of a system, such as the roles and features that should be installed, the configuration of specific applications, and the desired state of system settings and files. The DSC engine then ensures that the actual state of the system matches the desired state. If there are any discrepancies, DSC can automatically take corrective actions to bring the system back into compliance.

DSC can be used to manage configurations on individual servers or entire server farms, and it can be run locally or remotely, making it a powerful tool for managing large-scale IT infrastructure.

configuration ExampleDSC { node <NodeName> { # Define resource blocks here } } # Compile the configuration into a MOF file ExampleDSC -OutputPath .\ExampleDSC # Apply the configuration to the node Start-DscConfiguration -Path .\ExampleDSC -Wait -Verbose

Replace <NodeName> with the name of the server you want to configure. The resource blocks in the node section can be any DSC resources, such as File, WindowsFeature, or Service.

Here is an example of a desired state configuration for enabling the "Web Server (IIS)" role and "Static Content" feature on a Windows Server using PowerShell DSC:

Configuration IISInstall { Import-DscResource -ModuleName PSDesiredStateConfiguration Node 'localhost' { WindowsFeature IIS { Ensure = 'Present' Name = 'Web-Server' } WindowsFeature StaticContent { Ensure = 'Present' Name = 'Web-Static-Content' DependsOn = '[WindowsFeature]IIS' } } } IISInstall Start-DscConfiguration -Path .\IISInstall -Wait -Verbose

This configuration ensures that the IIS Web Server role and Static Content feature are installed on the local machine. The DependsOn property specifies that the installation of the Static Content feature depends on the installation of the IIS role.