I am in the process of a deep dive into DSC and I want to store my custom modules and DSC Resources in source control. To make it easy to run PowerShell modules you have to import them or have them on the PSModulePath environment variable. Since I don’t want to point a source repository to the default PowerShell module path, I want to add my custom module path to PSModulePath. This will save me some time when it comes to having to import modules and module changes. This means I will always be running the most recent version of my modules even the buggy ones, so if you do this, understand the implications.

It’s actually pretty easy to automate this with PowerShell. Since I already have some experience updating environment variables with PowerShell I just created a new script to add my custom module path to PSModulePath.

$currentModulePath = [Environment]::GetEnvironmentVariable("PSModulePath", "Machine")
$customModulePath = "C:\_DSC\DSCResources"
$newModulePath = $currentModulePath + ";" + $customModulePath

[Environment]::SetEnvironmentVariable("PSModulePath", $newModulePath, "Machine")

I complicated this script a bit so it is more self evident on what is happening (code as documentation – no comments necessary).

I can envision someone needing to also remove a path from PSModulePath, but this is enough to get started so I will leave it up to you, until I have a need for that :).

UPDATES

When running this script in an Invoke-Command on a remote session the modules aren’t immediately available if I tried to use modules in the new path. This is because the path is not updated on the remote session. A quick workaround for me was to remove the session and recreate it.

Get-PSSession | Remove-PSSession;

This removes all sessions so you may not want to do this. Since I don’t care about sessions I like it. This was just a one line change in my workflow script and it didn’t cause too much latency in the script execution. I know there are some other solutions that involve messing with the registry, but this is a one time deal so resetting the remote session works for me.