SSH Key Auth to GitHub on Win 10 w/ VSCode

My work computer has been using SSH keys to authenticate to GitHub for a while. But I’ve slept a few nights since I set that up and I have no clear memory of what I did.

I wanted to setup my home computer the the same way and struggled to figure out how to do it. So, I thought it might be worth documenting.

The secret (I think) … install git 2.20.0 or higher

In the end, the final change that made SSH key authentication work was updating my git installation from version 2.15.0 to 2.25.0. My work computer has 2.20.0 on it, so I figure that should be the minimum level.

Here’s an outline of the things I tried and notes about them:

	Work Computer	Home Computer	Notes
git (version)	2.20.0	2.15.0 –> 2.25.0	Didn’t work with 2.15.0. Finally worked with 2.25.0.
SSH keys	I don’t remember how I generated them. I think I generated the keys using ubuntu WSL.	Copied them from my work computer to my home computer using normal NTFS system (didn’t need Git Bash, WSL, or any of those). I did register the keys using ssh-add in `Git Bash`, ‘wsl’, and using the Windows 10 ssh-add (see Notes). But, in the end, I turned off Win10’s ssh-agent service and the SSH keys continued to be used for authentication.	On my current version of Win 10, you can start an ssh-agent service in windows. Which means you don’t need to to use a bash command prompt to execute `ssh-keygen` or `ssh-add` commands. Reminder: use `ssh-add –l` to list already registered keys.
Github PAT	I never created one for this machine.	I created one for this machine, and it would work for an individual commit (username: normal github account name, password: PAT)	I don’t think this is needed.

Submitting a Bug/Pull Request for Asp.Net Core

It’s great that the Asp.Net Core team has made the project open source. It makes finding bugs, resolving them and submit updates/pull requests tremendously more satisfying than when you would call Microsoft support, report your bug and hope the product team considered your problem high enough priority to justify their time.

Last week I put together a post on a NullReferenceException within the Microsoft.AspNetCore.Http.ItemsCollection object. I finished the post by filing a bug with the AspNetCore team (#16938). The next step I needed to do with download the source code for Asp.Net Core and create a fix for it.

So, the standard forking of the repository and creating a new branch to create the fix in was easy enough, but now came the interesting part. Submitting the Pull Request and receiving their feedback. The first thing that was pretty amazing was that I submitted the fix around 10 AM on Saturday morning (Pull Request #16947). By noon on a Saturday some one from the Asp.Net Core team had reviewed the pull request and already found improvements to the code. The best part of the review is that they are very talented programmers and found multiple ways to improve the unit test submitted and even found other errors in the original file that was being updated. They didn’t just review the code, they looked for ways to improve the overall product.

The fix I found for the NullReferenceException was to use a null-conditional operator to ensure that the exception didn’t occur. But, what they did was search the entire class for every place this might occur and suggested where else a null-conditional operator could be applied to prevent future issues. They are detailed.

The parts of my pull request they had the most feedback on were the unit tests, and the suggestions were are useful to simplify the code and get at the core of what was being tested. When running the unit tests on my local machine, I could tell that they really focused in how to make the unit tests as fast and efficient as possible. The dotnet test runner could run the 169 unit tests in the Microsoft.AspNetCore.Http library in under 4 seconds. For comparison, I’ve mostly been working with Powershell unit tests for a while, and loading up the Powershell runtime and the Pester module, before even running the tests, usually takes a good ~5 seconds.

Overall it was a pretty easy process and they accepted the update for inclusion in the Asp.Net Core 5.0 preview1 release. Now, for getting the fix merged into Asp.Net Core 3.X, that was a little more difficult (#17068).

Monitor and Download Latest .Net Core Installer

.NET Core has changed it’s IIS server installation model compared to .NET Full Framework. Full Framework updates were installable in offline installers, but they were also available through Windows Update/SCCM. However, with .NET Core the installer the IIS server installer, the “Hosting Bundle”, is only an offline installer that can be found by following these steps: (example for 2.2.7)

• Watching the github AspNetCore/releases page for new stable releases.
• Following the Download and Install link to the appropriate download.md.
• Finding the Downloads section and within the ASP.NET Core Runtime column, downloading the Hosting Bundle.

Even though this process is really quick, it can feel repetitive and feel like something you shouldn’t need to do. This feeling can be compounded if you missed that a new release was created weeks or months before and someone else points outs the update to you.

So, a small solution to these two minor inconveniences is to setup a watcher script which will monitor the AspNetCore teams github repository for new releases, and upon finding a new one will download the Hosting Bundle and notify you of the update. This solution could run on a nightly basis.

In this example script those previously mentioned pieces of functionality are provided by:

• PowerShellForGithub\Get-GitHubRelease
  
  This function can be used to pull back all the releases for a github repository and the results can be filtered to find the latest stable release.
  
  In order to know if the latest release is newer than the release you currently have on your servers, you could simply check the date stamp for that release was the current day. However, for this sample script, it’s going to assume you can query an external system to find out the latest installed version.
  
  
• Selenium \ SeleniumUcsb
  
  Selenium is used to navigate through the github release pages and find links to the download. It then downloads the Hosting Bundle installer by parsing through the pages to find the appropriate link. The parsing is actually a bit difficult to figure out sometimes, so an XPath Helper/tester for your browser can be really handy.
  
  
• Emailing
  
  Send-MailMessage … yeah, that’s pretty straight forward.

Powershell: Using a file hash to test for a change

The PowershellForGitHub module is great! But … sometimes it can be a bit verbose when it’s trying to help out new users/developers of the module. This isn’t a bad thing in any way, just a personal preference thing. And, the module owner, Howard Wolosky, is really open to suggestions. Which is great!

So, I opened a ticket (PowerShellForGitHub Issue #124) to explain my confusion over the warning messages. And, to be fair, I explained my confusion in a very confusing way. But, he was nice enough to work through it with me and we found that something we needed was a way to tell if someone had updated a settings file after downloading the module on their machine.

Enter, Get-FileHash.

This command looks like it’s been around for quite a while, but it does the classic job of creating a hash of a file. And, that hash can be stored in code, so that it can be used to check if a change in the file has occurred.

So, how to use the check.

Here’s the original code:

And, here’s the updated code using Get-FileHash:

PowerShellForGitHub–Adding Get-GitHubRelease

PowerShellForGitHub is an awesome powershell module for interacting with the GitHub API. It has a wide set of features that are already implemented and its supported by Microsoft(!!). You can also tell the amount of care the maintainer, Howard Wolosky, has put into it when you dig into the code and read through the inline documentation, contributing documentation and telemetry support(!!). BTW, if you ever need to create a PII transmittable string, check it out: Get-PiiSafeString.

One of the features I was looking for the other day was the ability to retrieve a list of releases for a repository. (I was building a script to monitor the dotnet/core releases; in order to build an ASP.NET Core Hosting Bundle auto-installer.)

I submitted a pull request of the update last week and was really impressed with all the automation in the pull request processing. The first thing that surprised me was the integrated msftclas bot (Microsoft Contribution License Agreements), which posted a legal agreement form that I (or the company I represent) consent to give Microsoft ownership of the code we contribute. It was soo smooth and easy to do.

Next was the meticulous level of comments and review notes on the pull request. If he made all those comments by hand, holy moly! That would be amazing and I would want to praise him for his patience and level of detail. Hopefully, some of the comments were stubbed out by a script/bot; which would be a really cool script to know about.

So, I’m gonna go through the comments and see if I can update this pull request.

• *facepalm* Wow, I really missed changing the name GitHubLabels.ps1 to GitHubReleases.ps1 in the .tests.ps1 file.
  
• White space in .tests.ps1: Ahhh … I can better see the white space formatting style now.
  
• Examples missing documentation: Hahaha! My mistake. It looks like I started writing them and got distracted.
  
• Telemetery: I loved the note:
  
  For these, I think it's less interesting to store the encrypted value of the input, but more so that the input was provided (simply in terms of tracking how a command is being used).
  
  Thank you for pointing that out! It makes complete sense.

In summary, a big Thank You to Howard Wolosky and the Microsoft team for making this module! It was a huge time saver and really informative on how to write Powershell code in a better way.