{"id":1861,"date":"2014-01-09T18:15:00","date_gmt":"2014-01-09T18:15:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/powershell\/2014\/01\/09\/separating-what-from-where-in-powershell-dsc\/"},"modified":"2024-02-22T14:36:33","modified_gmt":"2024-02-22T22:36:33","slug":"separating-what-from-where-in-powershell-dsc","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/powershell\/separating-what-from-where-in-powershell-dsc\/","title":{"rendered":"Separating “What” from “Where” in PowerShell DSC"},"content":{"rendered":"
\n

As you already know we introduced PowerShell Desired State Configuration to the world at our TechEd NA 2013 Session<\/a>. The session also introduced the notion of structural configuration (what)\u00a0and environmental configuration (where) (at the 25:50 min mark). Structural configuration defines what is needed and does not change based on the environment. For instance, a configuration can require IIS to be installed \u2013 whether we have one node, or many nodes, whether it is a development environment or a production environment. It does not matter – we need IIS installed. Environmental configuration defines the environment in which the configuration is deployed. For instance, the node names and source file locations can change from a development to a test to a production environment. <\/span><\/span><\/p>\n

 <\/p>\n

DSC offers the ability to separate structural configuration from environment configurational. This provides the ability to scale up or down a configuration across machines.<\/span><\/p>\n

\"Image<\/a><\/p>\n

The way to specify environmental configuration is through the <\/span>ConfigurationData<\/span> automatic parameter which is a hash table. Alternatively, the parameter can also take a .psd1 file containing the hashtable<\/span><\/span><\/span><\/p>\n

 <\/p>\n

PS C:\\> Get-Command MyConfiguration -Syntax<\/span><\/p>\n

\u00a0<\/span><\/p>\n

MyConfiguration [[-InstanceName]< string>] [[-OutputPath] <string>] [[-ConfigurationData]< hashtable>] <\/span><\/p>\n

\u00a0<\/span><\/p>\n

This hash table needs to have at least one key <\/span>AllNodes<\/span> \u2013 whose value is structured. ConfigurationData\u00a0can have any number of additional keys and value mappings added. For example:<\/span><\/span><\/p>\n

 <\/p>\n

$MyData<\/span> =<\/span> <\/span><\/p>\n

@{<\/span><\/p>\n

\u00a0\u00a0\u00a0 AllNodes =<\/span> @();<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 NonNodeData =<\/span> “”<\/span>\u00a0\u00a0 <\/span><\/p>\n

} <\/span><\/p>\n

\u00a0<\/span><\/p>\n

The Key of interest is <\/span>AllNodes<\/span>. Its value is an array. However each element of the array is a hash table in itself with NodeName being a required key<\/span><\/span><\/p>\n

 <\/p>\n

$MyData<\/span> =<\/span> <\/span><\/p>\n

@{<\/span><\/p>\n

\u00a0\u00a0\u00a0 AllNodes =<\/span> <\/span><\/p>\n

\u00a0\u00a0\u00a0 @(<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-1”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-2”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-3”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 );<\/span><\/p>\n

\u00a0\u00a0\u00a0 NonNodeData =<\/span> “”<\/span>\u00a0\u00a0 <\/span><\/p>\n

}<\/span><\/p>\n

\u00a0<\/span><\/p>\n

Each hash table entry in AllNodes <\/span>corresponds to configuration data for one node in the configuration. The hash table can have any number of other keys (other than the required <\/span>NodeName <\/span>key)<\/span><\/span><\/p>\n

 <\/p>\n

$MyData<\/span> =<\/span> <\/span><\/p>\n

@{<\/span><\/p>\n

\u00a0\u00a0\u00a0 AllNodes =<\/span> <\/span><\/p>\n

\u00a0\u00a0\u00a0 @(<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-1”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-2”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “SQLServer”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-3”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 );<\/span><\/p>\n

\u00a0\u00a0\u00a0 NonNodeData =<\/span> “”<\/span>\u00a0\u00a0 <\/span><\/p>\n

}<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0<\/span><\/p>\n

DSC provides 3 special variables for use within the configuration which can access elements from the configuration data.<\/span><\/p>\n

 <\/p>\n

1.\u00a0\u00a0\u00a0\u00a0 <\/span><\/span>$AllNodes<\/span>: It<\/span>is a special variable that will refer to the <\/span>AllNodes <\/span>collection. It also supports filtering using simplified .Where() and .ForEach() syntax. So you can author a configuration like this<\/span><\/span><\/p>\n

\n

configuration<\/span> MyConfiguration<\/span><\/span><\/p>\n

{<\/span><\/p>\n

\u00a0\u00a0\u00a0 node $AllNodes<\/span>.<\/span>Where{$_<\/span>.<\/span>Role -eq<\/span> “WebServer”<\/span>}.<\/span>NodeName<\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\n

 <\/p>\n

\u00a0<\/span>\u00a0\u00a0 }<\/span><\/p>\n

} <\/span><\/p>\n

\u00a0<\/span><\/p>\n

When the configuration is invoked with the <\/span>ConfigurationData<\/span> parameter the filter returns a set of nodes for use in the node statement. This avoids the need for having to hard code the node name in a configuration (or parameterizing it always). This is equivalent to writing the following (When the above configuration is invoked with <\/span>\u2013ConfigurationData<\/span>$MyData<\/span>presented above):<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

configuration<\/span> MyConfiguration<\/span><\/span><\/p>\n

{<\/span><\/p>\n

\u00a0\u00a0\u00a0 node Server1<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span><\/p>\n

\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0 node Server3<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span><\/p>\n

\u00a0\u00a0\u00a0 }<\/span><\/p>\n

} <\/span><\/p>\n

\u00a0<\/span><\/p>\n

2.\u00a0\u00a0\u00a0\u00a0 <\/span><\/span>$Node<\/span>: Once a set of nodes is filtered from <\/span>$AllNodes<\/span>, <\/span>$Node<\/span>can be used to refer to the current entry.<\/span><\/span><\/p>\n

\n

configuration<\/span> MyConfiguration<\/span><\/span><\/p>\n

{<\/span><\/p>\n

\u00a0\u00a0\u00a0 Import-DscResource<\/span> -ModuleName<\/span> xWebAdministration<\/span> -Name<\/span> MSFT_xWebsite<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0 node $AllNodes<\/span>.<\/span>Where{$_<\/span>.<\/span>Role -eq<\/span> “WebServer”<\/span>}.<\/span>NodeName<\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xWebsite Site<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> $Node<\/span>.<\/span>SiteName<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 PhysicalPath =<\/span> $Node<\/span>.<\/span>SiteContents<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 }<\/span><\/p>\n

} <\/span><\/p>\n

The above configuration is equivalent to writing the following (when evaluated with <\/span>$MyData<\/span>presented above)<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

configuration<\/span> MyConfiguration<\/span><\/span><\/p>\n

{<\/span><\/p>\n

\u00a0\u00a0\u00a0 Import-DscResource<\/span> -ModuleName<\/span> xWebAdministration<\/span> -Name<\/span> MSFT_xWebsite<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0 node Nana-VM-1<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xWebsite Site<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Website1”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 PhysicalPath =<\/span> “C:\\Site1”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span><\/p>\n

\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0 node Nana-VM-3<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xWebsite Site<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Website3”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 PhysicalPath =<\/span> “C:\\Site3”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span><\/p>\n

\u00a0\u00a0\u00a0 }<\/span><\/p>\n

} <\/span><\/p>\n

\u00a0<\/span><\/p>\n

Note<\/span><\/strong>: xWebsite is a resource that we published as part of DSC Resource Kit Wave 1. More information on the same can be found <\/em><\/span>here<\/span><\/a><\/em><\/span><\/p>\n

\u00a0<\/span><\/p>\n

If you want some properties to apply to all the nodes, then it can be specified with <\/span>NodeName <\/span>as \u201c<\/span>*<\/span>\u201d (Note: * is a special notion. Wildcards are not supported)<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0<\/span><\/p>\n

$MyData<\/span> =<\/span> <\/span><\/p>\n

@{<\/span><\/p>\n

\u00a0\u00a0\u00a0 AllNodes =<\/span> <\/span><\/p>\n

\u00a0\u00a0\u00a0 @(<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “*”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 LogPath\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “C:\\Logs”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-1”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteContents =<\/span> “C:\\Site1”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteName =<\/span> “Website1”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-2”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “SQLServer”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-3”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteContents =<\/span> “C:\\Site2”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteName =<\/span> “Website3”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 );<\/span><\/p>\n

} <\/span><\/p>\n

\u00a0<\/span><\/p>\n

Now every node has a LogPath property.<\/span><\/p>\n

\u00a0<\/span><\/p>\n

3.\u00a0\u00a0\u00a0\u00a0 <\/span><\/span>$ConfigurationData<\/span>: This variable can be used from within a configuration to access the configuration data hash table passed as a parameter. <\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

$MyData<\/span> =<\/span> <\/span><\/p>\n

@{<\/span><\/p>\n

\u00a0\u00a0\u00a0 AllNodes =<\/span> <\/span><\/p>\n

\u00a0\u00a0\u00a0 @(<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “*”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 LogPath\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “C:\\Logs”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-1”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteContents =<\/span> “C:\\Site1”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteName =<\/span> “Website1”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-2”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “SQLServer”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName =<\/span> “Nana-VM-3”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer”<\/span>;<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteContents =<\/span> “C:\\Site2”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SiteName =<\/span> “Website3”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 );<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0 NonNodeData =<\/span> <\/span><\/p>\n

\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ConfigFileContents =<\/span> (Get-Content<\/span> C:\\Template\\Config.xml<\/span>)<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0 }\u00a0\u00a0 <\/span><\/p>\n

} <\/span><\/p>\n

\u00a0<\/span><\/p>\n

configuration<\/span> MyConfiguration<\/span><\/span><\/p>\n

{<\/span><\/p>\n

\u00a0\u00a0\u00a0 Import-DscResource<\/span> -ModuleName<\/span> xWebAdministration<\/span> -Name<\/span> MSFT_xWebsite<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0 node $AllNodes<\/span>.<\/span>Where{$_<\/span>.<\/span>Role -eq<\/span> “WebServer”<\/span>}.<\/span>NodeName<\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xWebsite Site<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> $Node<\/span>.<\/span>SiteName<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 PhysicalPath =<\/span> $Node<\/span>.<\/span>SiteContents<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 File ConfigFile<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DestinationPath =<\/span> $Node<\/span>.<\/span>SiteContents +<\/span> “\\\\config.xml”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Contents =<\/span> $ConfigurationData<\/span>.<\/span>NonNodeData.<\/span>ConfigFileContents<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 }<\/span><\/p>\n

} <\/span><\/p>\n

\u00a0<\/span><\/p>\n

Here is a complete example using configuration data (already included in examples for\u00a0xWebAdministration module in DSC Resource Kit Wave 1<\/a><\/span>)<\/span><\/span><\/p>\n

 <\/p>\n

configuration<\/span> Sample_xWebsite_FromConfigurationData<\/span><\/span><\/p>\n

{<\/span><\/p>\n

\u00a0\u00a0\u00a0 # Import the module that defines custom resources<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 Import-DscResource<\/span> -Module<\/span> xWebAdministration<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0 # Dynamically find the applicable nodes from configuration data<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 Node $AllNodes<\/span>.<\/span>where{$_<\/span>.<\/span>Role -eq<\/span> “Web”<\/span>}.<\/span>NodeName<\/span><\/p>\n

\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # Install the IIS role<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 WindowsFeature IIS<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Web-Server”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # Install the ASP .NET 4.5 role<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 WindowsFeature AspNet45<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Web-Asp-Net45”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # Stop an existing website (set up in Sample_xWebsite_Default)<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xWebsite DefaultSite<\/span> <\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Default Web Site”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 State\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Stopped”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 PhysicalPath\u00a0\u00a0\u00a0 =<\/span> $Node<\/span>.<\/span>DefaultWebSitePath<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DependsOn\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “[WindowsFeature]IIS”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # Copy the website content<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 File WebContent<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SourcePath\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> $Node<\/span>.<\/span>SourcePath<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DestinationPath =<\/span> $Node<\/span>.<\/span>DestinationPath<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Recurse\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> $true<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Type\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Directory”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DependsOn\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “[WindowsFeature]AspNet45”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # Create a new website<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 xWebsite BakeryWebSite<\/span> <\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 {<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ensure\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Present”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> $Node<\/span>.<\/span>WebsiteName<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 State\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Started”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 PhysicalPath\u00a0\u00a0\u00a0 =<\/span> $Node<\/span>.<\/span>DestinationPath<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DependsOn\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “[File]WebContent”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 }<\/span><\/p>\n

}<\/span><\/p>\n

\u00a0<\/span><\/p>\n

# Content of configuration data file (e.g. ConfigurationData.psd1) could be:<\/span><\/p>\n

\u00a0<\/span><\/p>\n

# Hashtable to define the environmental data<\/span><\/p>\n

@{<\/span><\/p>\n

\u00a0\u00a0\u00a0 # Node specific data<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0 AllNodes =<\/span> @(<\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # All the WebServer has following identical information <\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “*”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 WebsiteName\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “FourthCoffee”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SourcePath\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “C:\\BakeryWebsite\\”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DestinationPath\u00a0\u00a0\u00a0 =<\/span> “C:\\inetpub\\FourthCoffee”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 DefaultWebSitePath =<\/span> “C:\\inetpub\\wwwroot”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer1.fourthcoffee.com”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Web”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @{<\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NodeName\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “WebServer2.fourthcoffee.com”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Role\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 =<\/span> “Web”<\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/span><\/p>\n

\u00a0\u00a0\u00a0 );<\/span><\/p>\n

}<\/span><\/p>\n

\u00a0<\/span><\/p>\n

# Pass the configuration data to configuration as follows:<\/span><\/p>\n

Sample_xWebsite_FromConfigurationData<\/span> -ConfigurationData<\/span> ConfigurationData.psd1 <\/span><\/span><\/p>\n

 <\/p>\n

Separating the environmental configuration from structural configuration helps author configuration without having to \u201chard code\u201d environment specific information in a configuration declaration. DSC provides a mechanism to do so but does not enforce it. The separation can be very specific to a configuration and its environment and each configuration author can use it as they seem fit.<\/span><\/p>\n

 <\/p>\n

Happy configuring !!!<\/span><\/p>\n

\u00a0<\/span><\/p>\n

Narayanan (Nana) Lakshmanan<\/span><\/p>\n

Development Lead – PowerShell DSC<\/span><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

As you already know we introduced PowerShell Desired State Configuration to the world at our TechEd NA 2013 Session. The session also introduced the notion of structural configuration (what)\u00a0and environmental configuration (where) (at the 25:50 min mark). Structural configuration defines what is needed and does not change based on the environment. For instance, a configuration […]<\/p>\n","protected":false},"author":600,"featured_media":13641,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[142,150,248,251,345,348],"class_list":["post-1861","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-powershell","tag-desired-state-configuration","tag-dsc","tag-powershell","tag-powershell-4-0","tag-windows-powershell-4-0","tag-windows-powershell-desired-state-configuration"],"acf":[],"blog_post_summary":"

As you already know we introduced PowerShell Desired State Configuration to the world at our TechEd NA 2013 Session. The session also introduced the notion of structural configuration (what)\u00a0and environmental configuration (where) (at the 25:50 min mark). Structural configuration defines what is needed and does not change based on the environment. For instance, a configuration […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/posts\/1861","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/users\/600"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/comments?post=1861"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/posts\/1861\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/media\/13641"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/media?parent=1861"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/categories?post=1861"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/tags?post=1861"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}