Show Arc error on 20H2 only if Arc intent is specified (Azure#15550)

* Show warning only if Arc intent is specified

Show warning only if Arc intent is specified on 20H2 OS.

* Updated Change Log

Updated Change Log on Arc error update logic

Author: digot007

src/StackHCI/Az.StackHCI.psm1

@@ -2367,43 +2367,49 @@ param(
 
             if($ArcCmdletsAbsentOnNodes.Count -ge 1)
             {
-                $ArcCmdletsNotAvailableErrorMsg = $ArcCmdletsNotAvailableError -f ($ArcCmdletsAbsentOnNodes -join ",")
-                Write-Error -Message $ArcCmdletsNotAvailableErrorMsg
-                $registrationOutput | Add-Member -MemberType NoteProperty -Name $OutputPropertyResult -Value [OperationStatus]::Failed
-                Write-Output $registrationOutput
-                return
-            }
-
-            $arcResourceId = $resourceId + $HCIArcInstanceName
-            $arcResourceGroupName = $ResourceGroupName
-
-            $arcres = Get-AzResource -ResourceId $arcResourceId -ApiVersion $HCIArcAPIVersion -ErrorAction Ignore
-
-            if($arcres -eq $null)
-            {
-                $arcres = New-AzResource -ResourceId $arcResourceId -ApiVersion $HCIArcAPIVersion -Force
-            }
-            else
-            {
-                if ($arcres.Properties.aggregateState -eq $ArcSettingsDisableInProgressState)
+                # Show Arc error on 20h2 only if -EnableAzureArcServer:$true is explicity passed by user
+                if($PSBoundParameters.ContainsKey('EnableAzureArcServer'))
                 {
-                    Write-Error -Message $ArcRegistrationDisableInProgressError
+                    $ArcCmdletsNotAvailableErrorMsg = $ArcCmdletsNotAvailableError -f ($ArcCmdletsAbsentOnNodes -join ",")
+                    Write-Error -Message $ArcCmdletsNotAvailableErrorMsg
                     $registrationOutput | Add-Member -MemberType NoteProperty -Name $OutputPropertyResult -Value [OperationStatus]::Failed
                     Write-Output $registrationOutput
                     return
                 }
             }
+            else
+            {
+                $arcResourceId = $resourceId + $HCIArcInstanceName
+                $arcResourceGroupName = $ResourceGroupName
 
-            $arcResourceGroupName = $arcres.Properties.arcInstanceResourceGroup
-            $arcAppName = $ResourceName + ".arc"
+                $arcres = Get-AzResource -ResourceId $arcResourceId -ApiVersion $HCIArcAPIVersion -ErrorAction Ignore
 
-            Write-Verbose "Register-AzStackHCI: Arc registration triggered. ArcResourceGroupName: $arcResourceGroupName"
-            $arcResult = Register-ArcForServers -IsManagementNode $IsManagementNode -ComputerName $ComputerName -Credential $Credential -TenantId $TenantId -SubscriptionId $SubscriptionId -ResourceGroup $arcResourceGroupName -Region $Region -AppName $arcAppName -ClusterDNSSuffix $clusterDNSSuffix -IsWAC:$IsWAC
+                if($arcres -eq $null)
+                {
+                    $arcres = New-AzResource -ResourceId $arcResourceId -ApiVersion $HCIArcAPIVersion -Force
+                }
+                else
+                {
+                    if ($arcres.Properties.aggregateState -eq $ArcSettingsDisableInProgressState)
+                    {
+                        Write-Error -Message $ArcRegistrationDisableInProgressError
+                        $registrationOutput | Add-Member -MemberType NoteProperty -Name $OutputPropertyResult -Value [OperationStatus]::Failed
+                        Write-Output $registrationOutput
+                        return
+                    }
+                }
 
-            if($arcResult -ne [ErrorDetail]::Success)
-            {
-                $operationStatus = [OperationStatus]::RegisterSucceededButArcFailed
-                $registrationOutput | Add-Member -MemberType NoteProperty -Name $OutputPropertyErrorDetail -Value $arcResult
+                $arcResourceGroupName = $arcres.Properties.arcInstanceResourceGroup
+                $arcAppName = $ResourceName + ".arc"
+
+                Write-Verbose "Register-AzStackHCI: Arc registration triggered. ArcResourceGroupName: $arcResourceGroupName"
+                $arcResult = Register-ArcForServers -IsManagementNode $IsManagementNode -ComputerName $ComputerName -Credential $Credential -TenantId $TenantId -SubscriptionId $SubscriptionId -ResourceGroup $arcResourceGroupName -Region $Region -AppName $arcAppName -ClusterDNSSuffix $clusterDNSSuffix -IsWAC:$IsWAC
+
+                if($arcResult -ne [ErrorDetail]::Success)
+                {
+                    $operationStatus = [OperationStatus]::RegisterSucceededButArcFailed
+                    $registrationOutput | Add-Member -MemberType NoteProperty -Name $OutputPropertyErrorDetail -Value $arcResult
+                }
             }
         }
 

src/StackHCI/ChangeLog.md

@@ -18,6 +18,8 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* Made changes to show Arc not supported error on 20H2 only if intent to enable Arc is specified by user.
+    - Show Arc not supported error on 20H2 only if -EnableAzureArc:$true is specified in registration Cmdlet.
 
 ## Version 0.8.0
 * Made changes to use FQDN while connecting to nodes and the cluster.