Telemetry in PowerShellForGitHub

The PowerShellForGitHub module has a number of interesting things about it. One interesting aspect is it’s implementation for collecting telemetry data, Telemetry.ps1. Telemetry is very useful to help answer the questions of:

• What aspects of your service are being used most frequently?
• What aspects are malfunctioning?
• Are there particular flows of usage which can be simplified?

But, to be able to collect the data necessary to answer those questions you have to make the collection process incredibly easy. The goal would be to boil down the collection process to single line of code. And that’s what PowerShellForGitHub tried to do.

The level of data collection the module provides does take more than a single of line of code to use, but it’s so easily done as a part of the development process, it doesn’t feel like “extra work” or “overhead”. Here’s a snippet from GitHubRelease.ps1’s Get-GitHubRelease:

Looking through the function you can see a hashtable called $telemtryProperties created earlier on and it’s properties are slowly filled in as the function continues. Eventually, it gets to the point where a common function, Invoke-GHRestMethodMultipleResults is called and the telemetry information is passed off the underlying provider.

All of the hard work of setting up where the information will be collected and how it’s collected it abstracted away, and it boils down to be a subfeature of a single function, Invoke-GHRestMethodXYZ. Boiling everything down to that single line of code is what makes the telemetry in that module soo useful: it’s approachable. It’s not a headache that you have to go setup yourself or get permissions too, it just works.

To make it work at that level was no easy feat though! The code which makes all of that possible, including the amazing supplementary function’s like Get-PiiSafeString, is really long and involves the usage of nuget.exe to download and load Microsoft’s Application Insights and Event Tracing .NET libraries. These are hidden away in Telemetry.ps1 and NugetTools.ps1.

So, given the idea that “Telemetry is an incredibly useful and necessary piece of software development in order to answer the questions asked at the top of this article”, the new question becomes “How can you refactor the telemetry code from PowerShellForGitHub to be an easy to reuse package that any PowerShell module could take advantage of?”