Dynamically Determine a DSC Configuration Name Inside a Configuration


I ran across a scenario where I needed to reference the name of the configuration inside the configuration. I was looking for an automatic variable that contained this information, however I was unable to locate one searching online or by asking colleagues. The suggestions I received were to call the Get-PSCallStack cmdlet or use the $MyInvocation automatic variable.

To test these options, I created a small config and wrote the output of the options using Write-Verbose.

Get-PSCallStack

Configuration MyConfig
{
    Write-Verbose -Message ( Get-PSCallStack | Format-Table -AutoSize | Out-String )
}

MyConfig -Verbose

VERBOSE:
Command       Arguments
-------       ---------
              {}
Configuration {ArgsToBody=System.Collections.Hashtable, Name=MyConfig, ResourceModuleTuplesToImport=, Body=...
MyConfig      {Verbose=True}
<ScriptBlock> {}

The configuration name "MyConfig" is the third item in the array, and therefore would be referenced like `(Get-PSCallStack)[2].Command`. Not terribly bad, but not as simple as I would like.

$MyInvocation

Configuration MyConfig
{
    Write-Verbose -Message ( $MyInvocation | Format-List -Property * | Out-String )
}

MyConfig -Verbose

VERBOSE: 

MyCommand             : 
BoundParameters       : {}
UnboundArguments      : {}
ScriptLineNumber      : 7
OffsetInLine          : 1
HistoryId             : 14
ScriptName            : 
Line                  : MyConfig -Verbose
PositionMessage       : At line:7 char:1
                        + MyConfig -Verbose
                        + ~~~~~~~~~~~~~~~~~
PSScriptRoot          : 
PSCommandPath         : 
InvocationName        : 
PipelineLength        : 0
PipelinePosition      : 0
ExpectingInput        : False
CommandOrigin         : Internal
DisplayScriptPosition :

The "Line" property of $MyInvocation contains the full command that was executed. I could use some string manipulation to retrieve the name of the configuration, however Get-PSCallStack is simpler at this point.

$MyTypeName

At this point, Get-PSCallStack looks like the best option, however I was still curious if there is an automatic variable that contains only the configuration name. To investigate the variables available inside the configuration, I executed the following:

Configuration MyConfig
{
    Write-Verbose -Message ( Get-Variable | Where-Object -FilterScript { $_.Value -match '^MyConfig$' } | Out-String )
}

MyConfig -Verbose

VERBOSE:
Name       Value 
----       -----
MyTypeName MyConfig

Success! There is an automatic variable called $MyTypeName that contains only my configuration name. This is the easy button option I was looking for.

Comments (0)

Skip to main content