Executing a powershell script stored as a gist

Introduction

I have been using Chocolatey to manage standard software builds for freshly created virtual machines (VM). I use a Mac and that requires me to stand up a Windows VM from time to time (cough Power BI) or I may want to run a SQL Server VM on Azure. Chocolatey allows me to preserve disk space by giving me the ability to writing a config script which I can fire up on a fresh VM and Chocolatey will proceed to download and install all defined software. This gives me the ability to create a VM, fire off a config, do some work and then clean up afterwards.

At some point I will write up some posts on Chocolatey as it’s a real time saver.

Objective

I have configured my build scripts as Powershell scripts because they install Chocolatey first. This allows me to run the build on a vanilla Windows VM. At present I copy the script to the VM and execute it. The objective is to avoid having to copy the file. My chocolatey scripts are hosted on github, so what I want to do is define a script that will execute the remote script. It’s worth noting, Chocolatey has the ability to fire configs stored as gists (does it? I am sure it does, I will confirm this) but that requires you to have Chocolatey installed first. Using this approach I can fire this on a vanilla VM, have chocolatey install and then install all remaining software.

Building the command

I have placed a gist at that simply writes “Hello World” to the console here;

https://gist.github.com/justinjbird/9118a3a5dfdecad19492b3e8ad54f81f

In order to use it in our command we need to get the plain text version. If we add /raw to the end of the URL this will present us with just that;

https://gist.github.com/justinjbird/9118a3a5dfdecad19492b3e8ad54f81f/raw

So now that we have defined that, we can fire the gist using Invoke-Expression ;

Invoke-Expression ((New-Object System.Net.WebClient).DownloadString('https://gist.github.com/justinjbird/9118a3a5dfdecad19492b3e8ad54f81f/raw'))

And there you have it!

So changing the URL for my chocolatey script gist, I can now copy and paste the command straight into the command line and kick off my automated builds. There is probably more I can do to automate this, still learning as I go!