Introduction of Windows PowerShell "Desired State Configuration"

 

Did you heard about “PowerShell DSC”?  NO?  

You must me kidding me!!

Come on, these days it is more famous and in demand compare to “  Justin Bieber” and “ Shakira” ;)

 

Ok, jokes a part.

 

PowerShell DSC is the most uber-cool feature in PowerShell v4.

I love it.

It is introduced as the part of “Windows PowerShell V4”{wmf 4.0}.

Why you care? And what it do for you?

 

If you are lazy administrator, then it is a blessing for you, if you are busy administrator then it is a robot for you to help you out. It is a very good way to manage our IT infrastructure.

As an example, you can automate the whole process of deploying website using DSC, from installing IIS, configuring them, and copy your website content to the IIS server.

Imagine, you just need to create a script once and that’s all, you can use it with any or many servers.

DSC a new management platform for windows PowerShell, you just need to declare how you want to configure your software environment and it will do the rest for you.  

You can also set dependencies, for example, you can set that website won’t be copied, until IIS is not installed).

 DSC syntax is declarative and it make maintaining the configuration much easier.

 

Convinced? Yes? Good.

 

DSC work with resource providers, by default there are 12 resource providers in WMF 4.0. You can also create your custom resource and providers too.

List of Default Resources in WMF 4.0

Provider	Description
Windows PowerShell Desired State Configuration Archive Resource	Unpacks archive (.zip) files at specific paths on target nodes.
Windows PowerShell Desired State Configuration Environment Resource	Manages system environment variables on target nodes.
Windows PowerShell Desired State Configuration File Resource	Manages files and directories on target nodes.
Windows PowerShell Desired State Configuration Group Resource	Manages local groups on target nodes.
Windows PowerShell Desired State Configuration Log Resource	Logs configuration messages.
Windows PowerShell Desired State Configuration Package Resource	Installs and manages packages, such as Windows Installer and setup.exe packages, on target nodes.
Windows PowerShell Desired State Configuration Process Resource	Configures Windows processes on target nodes.
Windows PowerShell Desired State Configuration Registry Resource	Manages registry keys and values on target nodes.
Windows PowerShell Desired State Configuration Role Resource	Adds or removes Windows features and roles on target nodes.
Windows PowerShell Desired State Configuration Script Resource	Runs Windows PowerShell script blocks on target nodes.
Windows PowerShell Desired State Configuration Service Resource	Manages services on target nodes.
Windows PowerShell Desired State Configuration User Resource	Manages local user accounts on target nodes.

 

DSC Resource Kit Waves

 

To add the extra resources, you can download the DSC Resource Kit Wave1, Wave2, and Wave3 too. These Wave kits has extra configuration resources apart from 12 default resources.

 

DSC Resource Kit wave 1

http://blogs.msdn.com/b/powershell/archive/2013/12/26/holiday-gift-desired-state-configuration-dsc-resource-kit-wave-1.aspx

 

 

Resource	Description
xComputer	Name a computer and add it to a domain/workgroup
xVHD	Create and managed VHDs
xVMHyperV	Create and manage a Hyper-V Virtual Machine
xVMSwitch	Create and manage a Hyper-V Virtual Switch
xDNSServerAddress	Bind a DNS Server address to one or more NIC
xIPAddress	Configure IPAddress (v4 and v6)
xDSCWebService	Configure DSC Service (aka Pull Server)
xWebsite	Deploy and configure a website on IIS

 

 

DSC Resource Kit wave 2

http://blogs.msdn.com/b/powershell/archive/2014/02/07/need-more-dsc-resources-announcing-dsc-resource-kit-wave-2.aspx

 

Resource	Description	Module Name
xADDomain	Create and manage an Active Directory Domain	xActiveDirectory
xADDomainController	Create and manage an AD Domain Controller	xActiveDirectory
xADUser	Create and manage an AD User	xActiveDirectory
xWaitForADDomain	Pause configuration implementation until the AD Domain is available.  Used for cross machine synchronization.	xActiveDirectory
xSqlServerInstall	Create and manage a SQL Server Installation.	xSqlps
xSqlHAService	Create and manage a SQL High Availability Service.	xSqlps
xSqlHAEndpoint	Create and manage the endpoint used to access a SQL High Availability Group.	xSqlps
xSqlHAGroup	Create and manage a SQL High Availability Group.	xSqlps
xWaitForSqlHAGroup	Pause configuration implementation until a SQL HA Group is available.  Used for cross machine synchronization.	xSqlps
xCluster	Create and manage a cluster.	xFailOverCluster
xWaitForCluster	Pause configuration until a cluster is available.  Used for cross machine synchronization.	xFailOverCluster
xSmbShare	Create and manage a SMB Share.	xSmbShare
xFirewall	Create and manage Firewall rules	xNetworking
xVhdFile	Manage files to be copied into a Vhd.	xHyper-V
xWebsite	Added functionality to xWebsite to support configuration of https websites.	xWebAdministration
xVhd	Bug fixes	xHyper-V

 

DSC Resource Kit wave 3

http://blogs.msdn.com/b/powershell/archive/2014/03/28/dsc-resource-kit-wave-3.aspx

 

Module	Resource	Description
xWebAdministration	xWebAppPool	Create, remove, start, stop an IIS Application Pool
	xWebVirtualDirectory	Create or remove a virtual directory
	xWebApplication	Create or remove a web application
	xWebConfigKeyValue	Configure AppSettings section of Web.Config
xDatabase	xDatabase	Create, drop & deploy databases
	xDBPackage	Backup & restore databases
xSystemSecurity	xUAC	Enable or disable User Account Control prompt
	xIEEsc	Enable or disable IE Enhanced Security Configuration
xRemoteDesktopSessionHost	xRDSessionDeployment	Creates and configures a deployment in RDSH.
	xRDSessionCollection	Creates a RDSH collection.
	xRDSessionCollectionConfiguration	Configures a RDSH collection.
	xRDRemoteApp	Publish applications for your RDSH collection
xPSDesiredStateConfiguration	xWindowsProcess	Adds ability to run as a specific user to the existing WindowsProcess resource
	xService	Update to existing Service resource to include create/configure service
	xRemoteFile	Download files from a URI
	xPackage	Adds ability to run as a specific user to the existing resource, includes VS Setup
	xArchive	Create, update, extract a Zip file
	xEndpoint	Creates a remoting endpoint
Updates	xDscResourceDesigner, xComputer, xVMHyperV, xDNSServerAddress	Feature additions and bug fixes

 

Naming conventions,

 

The resource and modules those names are started with “X” are means they are experimental, and those resource and modules are starts with “c” means, they are supported and provided by community. Microsoft reserve resourced and module name without any prefixed (“x”,”c”) for future use, if you are going to create you own custom resources, make sure, you can add some “prefix” in it for safe side J

 

How it works.

 

There are few steps to make DSC working

1.      Create a DSC Configuration script.

2.      Execute DSC configuration script.

a.      When we run the configuration script, it produce a MOF file.

3.      Deploy it

a.      Using Pull Method

                                                              i.      HTTP

                                                            ii.      HTTPS

b.      Using Push Method

                                                              i.      Manual Method

 

When we deploy the MOF files to the node (computers), they will start configuring themselves.  

Managed Object Format

DSC is has a dependency on MOF, when we run  the DSC configuration script  it export the “MOF” document file.

So what is the MOF?

As per Microsoft documentation “Managed Object Format (MOF) is the language used to describe Common Information Model (CIM) classes.

            Source : http://msdn.microsoft.com/en-us/library/aa823192(v=vs.85).aspx ”

 

 

That's all for today, see you in next blog post.

Thanks .

Regards

Aman Dhally

 

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