Get-AzureRMResource by tag when tag value is "unknown" displays all resources

[sluhn-woodrum]

Description

From this article: https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-group-using-tags

When performing this command, I receive an output of all resources in the resource group $RG.

(Get-AzureRmResource -ResourceGroupName $RG -Tag @{cost_center="unknown"}).Name

In this case, all but a few resources have a defined cost_center, and I have a subscription policy that places an "unknown" value for the tag "cost_center". This is using Azure Powershell 6.5. Previously, I used the command Find-AzureRmResource -TagName "cost_center" -TagValue "unknown" which pulled this list of resources that needed to be updated.

If I change the command (and update one of the resources to a cost_center of abc123, the PS command just returns the 1 resource. Additionally, the Azure portal properly displays the "unknown" cost center resources appropriately, so I believe this to be a bug in Azure PS 6.5

Script/Steps for Reproduction

(Get-AzureRmResource -ResourceGroupName $RG -Tag @{cost_center="unknown"}).Name

Module Version

Get-Module -Name AzureRM -ListAvailable

Directory: C:\Program Files\WindowsPowerShell\Modules

ModuleType Version Name ExportedCommands

---

Script 6.5.0 AzureRM
Script 5.7.0 AzureRM

Environment Data

$PSVersionTable

Name Value

---

PSVersion 5.1.17134.137
PSEdition Desktop
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 10.0.17134.137
CLRVersion 4.0.30319.42000
WSManStackVersion 3.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1

Debug Output

[sluhn-woodrum]

Update: The following syntax also has the same issue, whereby the value of "unknown" displays all resources in the RG.

Get-AzureRmResource -ResourceGroupName $RG -Tagname "cost_center" -TagValue "unknown" | ft

[cormacpayne]

@Woodrum good catch! I'm able to reproduce this on my machine. It looks like our logic is incorrect when handling the scenario where both a name and value are provided, but is correct when only one of the two is provided. Let me open a PR to fix this and hopefully get it into our next release.

In the meantime, you can workaround this issue with the following commands:

$name = "cost_center"
$value = "unknown"
Get-AzureRmResource -ResourceGroupName $RG | where { $_.Tags[$name] -eq $value } | ft

[sluhn-woodrum]

@cormacpayne - thanks a lot... the workaround is great. To be clear, the command did work when the value I passed was anything but "unknown". So passing both a name and value works, but if the value is "unknown" it displayed all resources.

[cormacpayne]

This has been fixed and will be available in the 6.6.0 release of AzureRM