I Hate PowerShell (Installment 3783)

So, I know I've skipped a few numbers since my I Hate PowerShell (Installment 3769) post. That post still applies and, yes, there've been several more annoyances encountered since authoring that post.

For the project I'm currently working on, I can only access my remote Windows (Server 2022) hosts using AWS's  FleetManager service. The VPCs are otherwise configured to block access via direct RDP.

At any rate, the first time I login, I fire up PowerShell. I go to type into the resulting "terminal" window and… nothing. The window doesn't accept my keyboard input. Perplexed, I Slack the teammate who asked me to write the automation for the Windows provisioning-tasks that he'd been doing manually. I note my problem to him. He tells me, "install PowerShell 7".

I update the userData I pass as part of launching my EC2 so as to implement that advice. I wait for the userData's execution to complete and then login. Once the remote desktop session becomes fully responsive, I fire up powershell …and find that I am still unable to type. Perplexed, I do some digging around and find that "upgrade to PowerShell 7" doesn't _actually_ upgrade PowerShell, it just installs a second, newer version of PowerShell alongside the system default. If I want to access the newer version, I need to call `pwsh`, instead. So, I do so. The new window opens and, as advertised, I'm able to type into that window.

Now, I'm a person possessed of significant curiousity. As such, my curious brain thinks, "what happens if I call `powershell` from the PS7 window I'm able to type into". To sate my curiosity, I do so. Suddenly, the window I was previously able to type into no longer accepts keyboard input.

So, yeah, if I want to be able to type into windows opened from the default PowerShell version, I need to add some further plumbing to my userData. Specifically, I need to include some logic to update the default PowerShell installation's `PSReadLine` module.

Notionally, I could skip the installation of PS7. However, its installation seems to be the default work-around for this project (still don't know if I'd call that an "anti-pattern" or not). As such, I fear that not having it installed will result in the eventual users of my automation screaming about it not being installed.

At any rate, if I want to be able to type into the default PowerShell version and I want PowerShell 7 available for others' use, my userData payload needs to look like:

# Ensure the default PowerShell (v5.x) windows accept typed-in content
Install-PackageProvider -name NuGet -Force
Install-Module `
  -Name PSReadLine `
  -Repository PSGallery `
  -Force

# Install PowerShell 7
iex "& { $(irm https://aka.ms/install-powershell.ps1) } -UseMSI"

So. Yeah. But, at least my deployment target works. 

Interestingly, I don't seem to run into the "can't type into the window" problem if I use the AWS SSM CLI to login. Or maybe I didn't start trying that route until I was already including the PSReadLine update-juju into my userData payload?

Also interestingly, because the PS7 installation is a parallel installation, if I want to use the  AWS SSM CLI to login directly to a PS7 session, I have to update my CLI-access invocation from:

aws ssm start-session --target <INSTANCE_ID>

To:

aws ssm start-session --target <INSTANCE_ID> \
  --document-name AWS-StartInteractiveCommand \
  --parameters command="pwsh"

I guess the "don't try to change the system-wide PS version" guidance that search-results are showing me are a lot like "don't try to replace the system-default Python version" cautions for Red Hat distros?