Make e2e var loading faster (#3103)

e2e/test/prerequisites/E2ETestsSetup/LoadEnvironmentVariablesFromKeyVault.ps1

@@ -19,7 +19,7 @@ Function Connect-AzureSubscription()
 
     if (-not $azureContext)
     {
-        Write-Host "`nPlease login to Azure..."
+        Write-Host "`nPlease login to Azure."
         az login
         $azureContext = az account show
     }
@@ -28,7 +28,7 @@ Function Connect-AzureSubscription()
     $sub = az account show --output tsv --query id
     if ($sub -ne $SubscriptionId)
     {
-        Write-Host "`nSelecting subscription $SubscriptionId`n"
+        Write-Host "`nSelecting subscription $SubscriptionId.`n"
         az account set --subscription $SubscriptionId
     }
 
@@ -37,16 +37,17 @@ Function Connect-AzureSubscription()
 
 Connect-AzureSubscription | Out-Null
 
-# Load all secrets from KeyVault and set the appropriate Environment Variable
+# Load all secrets from KeyVault and set the appropriate environment variable
 $ids = az keyvault secret list --subscription $SubscriptionId --vault-name $KeyVaultName --query '[*].id' --output tsv
-ForEach ($id in $ids)
-{
+Write-Host "`nSetting environment variables:"
+$ids | ForEach-Object -Parallel {
     # az keyvault secret show does not return a name in its properties so we need to extract it from the id
-    # The ids have parts seperated by / and extracting the 5th part gets us the name of the Key
+    $value = az keyvault secret show --subscription $using:SubscriptionId --id $_ --query 'value' --output tsv
+
+    # The ids have parts separated by a '/' and extracting the 5th part gets us the name of the Key
     # After we extract the name of the Key, we also want to replace dashes with underscores so that we convert it to the correct Environment Vairable name to be set
     # Ex: https://test-kv.vault.azure.net/secrets/IOTHUB-NAME/f7953b248a3e46cfa6fc59651794db2e - Extract IOTHUB-NAME and convert to IOTHUB_NAME
-    $name = $id.split('/')[4].Replace('-', '_')
-    Write-Host("Setting Environment Variable $name")
-    $value = az keyvault secret show --subscription $SubscriptionId --id $id --query 'value' --output tsv
-    Set-Item -Path Env:$name -Value "$value"
+    $envVarName = $_.split('/')[4].Replace('-', '_')
+    Write-Host "`t$envVarName"
+    Set-Item -Path Env:$envVarName -Value "$value"
 }