“Incorrect padding” when trying to create managed Kubernetes cluster on Azure with AKS

Summary: I get an error when trying to create an AKS cluster from the command line.

Repro:

1. Installed azure-cli, logged in to account
2. az aks create --resource-group cb_aks_spike --name cbakscluster (resource group already exists)
3. I also tried az aks create --resource-group cb_aks_spike --name cbakscluster --generate-ssh-keys

Expected: The AKS cluster creation to start.

Actual: Error: az aks create: error: Incorrect padding

Notes: I initially posted this on Stack Overflow since I assumed it was something I did wrong, but after working through it with @benofben I think it could be a bug (or at least a confusing error message).

This error doesn’t occur when @benofben did it from bash on a Mac, and also doesn’t occur for me when I tried it in Cloud Shell-PowerShell

Environment summary

azure-cli (2.0.31) Windows 10 Enterprise 100.16299 Windows Powershell 5.1.16299.251

[DonaldAirey]

I’m a consultant at a customer site. I’m unable to control the name of the user directories and the one I’ve been given - “C:\Users\don airey” - has this issue. This command in the Repo above works fine on my home machine where my user directory is “C:\Users\DAirey” but fails when I’m at my client’s site. This is still a bug. Please fix it.

[tjprescott]

Try the following workaround: ssh-keygen -i -f existing_key.pub > formatted_key.pub

See related issue https://github.com/Azure/azure-cli/issues/2386 where this is confirmed to be a bug.