ResourceGroup default doesn't work properly in AzurePSDrive in Azure Cloud Shell

[HemantMahawar]

Description

In Azure Cloud Shell's AzurePSDrive, when you try to invoke a cmdlet without specifying resourcegroup, the cmdlet errors due to multiple values defined in PSDefaultParameterValues

Script/Steps for Reproduction

Navigate to a resourcegroup inside AzurePSDrive and call a Get-AzureRM*cmdlet that takes a resourcegroup parameter

cd Azure:\<subscription name>\ResourceGroups\<resource group name>
Get-AzureRmVpnClientPackage

#Output
WARNING: Multiple different default values are defined in $PSDefaultParameterValues for the 
parameter matching the following name or alias: ResourceGroupName. These defaults have been ignored.

cmdlet Get-AzureRmVpnClientPackage at command pipeline position 1
Supply values for the following parameters:
(Type !? for Help.)
ResourceGroupName:

Module Version

Get-Module -Name AzureRM -ListAvailable

#Output 
          Directory: C:\Program Files\WindowsPowerShell\Modules

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Script     5.4.0      AzureRM

Environment Data

$PSVersionTable

#Output
Name                           Value
----                           -----
PSVersion                      5.1.14393.1944
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.14393.1944
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

Root Cause

AzurePSDrive defines a default value of resourcegroup parameter for *-AzureRM cmdlets

$PSDefaultParameterValues['*-AzureRM*:ResourceGroupName']

#Output
if($pwd -like 'Azure:\*\ResourceGroups\*'){($pwd -split '\\')[3]}

[maddieclayton]

Fixed in PR linked above. @HemantMahawar Please let me know if this does not fix the issue on CloudShell when the release is deployed on next Tuesday.

[HemantMahawar]

@maddieclayton Shouldn't the fix be specific to AzurePSDrive in Cloudshell instead of all up across Cloudshell? The way I understand the fix is to ignore setting PSDefaultParameterValues for AzureRM cmdlets in Cloudshell all up.

Though, I don't know how often ResourceGroupName defaults are set for AzureRM* cmdlets.

[HemantMahawar]

Moreover, AzurePSDrive ships for non-Cloudshell scenarios as well. And it would be applicable for those scenarios as well see here

[HemantMahawar]

@maddieclayton Thinking a bit more on this and talking to folks who owns AzurePSDrive module, looks like the fix should be done at AzurePSDrive layer as it sits on top of AzureRM* module and SHiPS provider. Do you agree? /cc @raghushantha.

[maddieclayton]

@HemantMahawar Do you know of an easy way to determine whether or not the user is running on the scenarios that we want to disable Set-AzureRmDefault for? Aaron told me that the ACC_CLOUD environment variable was the correct way to determine that, but it seems like this is incorrect.

[maddieclayton]

Summary of offline discussion: we should only disable Set-AzureRmDefault when we are within PSDrive. Current fix disables Set-AzureRmDefault in CloudShell, but this is not a permanent fix because PSDrive is available outside of CloudShell and not all CloudShell is run within PSDrive. CloudShell team will work on their side to disable/remove PSDefaultParameterValues set by Set-AzureRmDefault when inside of PSDrive, and reenable/add back the PSDefaultParameterValues set by Set-AzureRmDefault when the user cds out of PSDrive.