Using PowerShell Desired State Configuration to Unzip Files

A couple of months ago I wrote a blog about a PowerShell Function to Unzip Files Using the .NET Framework 4.5 with Fallback to COM. I’ve since discovered that the new Desired State Configuration (DSC) feature in PowerShell version 4 can unzip files. You probably wouldn’t use this feature just to unzip a single file to a single server, but it does open up some interesting possibilities.

This blog article is not meant to be an all inclusive tutorial on DSC, it’s only meant to give you a peek inside the built-in DSC Archive Resource capabilities.

First, define your DSC configuration to create your MOF (Managed Object Format) file:

configuration UnZipFile {

    param (
        [Parameter(Mandatory=$True)]
        [string[]]$ComputerName,

        [string]$Path,
        [string]$Destination
    )

    node $ComputerName {

        archive ZipFile {
        Path = $Path
        Destination = $Destination
        Ensure = 'Present'

        }

    }

}

Notice that by parameterizing the configuration, I’m able to use my parameters instead of having to rewrite the configuration each time:

dsc-archive1.png

Voila! MOF file created:

UnzipFile -ComputerName Server01 -Path \\dc01\Share\ServerAdd.zip -Destination C:\

dsc-archive2.png

Since I defined the ComputerName parameter as mandatory, if I forget to specify that parameter I’ll be prompted for a value for it. I can also specify more than one value and create multiple MOF files for different nodes, all with a single command:

dsc-archive3.png

Now I’ll apply this configuration to Server01 to place it in the desired state:

Start-DscConfiguration UnZipFile -ComputerName Server01 -Wait -Verbose

dsc-archive4.png

The first time I ran this command, I thought there was a problem with the archive file due to the messages about files missing or not being a file. This is actually DSC checking the destination to see if the files already exist.

I removed one of the files and reapplied the state to confirm that the messages about files missing are indeed about the destination and not the source:

dsc-archive5.png

What I really like is that reapplying the state only extracted the one missing file and not the entire archive since all of the other files already existed.

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