From 13f8938a6c2ab79d92de8cb2a2e5bb4a03388660 Mon Sep 17 00:00:00 2001
From: Kyriakos Oikonomakos <koikonom@users.noreply.github.com>
Date: Thu, 22 Jul 2021 16:28:22 +0100
Subject: [PATCH] support for Azure Event Hubs Namespace Premium tier (#12695)

Adds support for the Premium tier of the event hubs namespace resource.
It is not possible to actually move from/to that tier so setting the sku
to `Premium` forces the resource to be re-created.

This will also throw an error if someone attempts to create a premium
namespace without setting zone_redundant to true.
---
 .../eventhub/eventhub_namespace_resource.go   | 22 ++++++++++++--
 .../eventhub_namespace_resource_test.go       | 30 +++++++++++++++++++
 .../docs/r/eventhub_namespace.html.markdown   |  2 +-
 3 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/azurerm/internal/services/eventhub/eventhub_namespace_resource.go b/azurerm/internal/services/eventhub/eventhub_namespace_resource.go
index e35630fced2a..f0ee82c183ee 100644
--- a/azurerm/internal/services/eventhub/eventhub_namespace_resource.go
+++ b/azurerm/internal/services/eventhub/eventhub_namespace_resource.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/Azure/azure-sdk-for-go/services/preview/eventhub/mgmt/2018-01-01-preview/eventhub"
@@ -69,8 +70,9 @@ func resourceEventHubNamespace() *pluginsdk.Resource {
 				Required:         true,
 				DiffSuppressFunc: suppress.CaseDifference,
 				ValidateFunc: validation.StringInSlice([]string{
-					string(eventhub.Basic),
-					string(eventhub.Standard),
+					string(namespaces.SkuNameBasic),
+					string(namespaces.SkuNameStandard),
+					string(namespaces.SkuNamePremium),
 				}, true),
 			},
 
@@ -249,6 +251,22 @@ func resourceEventHubNamespace() *pluginsdk.Resource {
 
 			"tags": tags.Schema(),
 		},
+		CustomizeDiff: pluginsdk.CustomizeDiffShim(func(ctx context.Context, d *pluginsdk.ResourceDiff, v interface{}) error {
+			oldSku, newSku := d.GetChange("sku")
+			if d.HasChange("sku") {
+				if strings.EqualFold(newSku.(string), string(namespaces.SkuNamePremium)) || strings.EqualFold(oldSku.(string), string(namespaces.SkuTierPremium)) {
+					log.Printf("[DEBUG] cannot migrate a namespace from or to Premium SKU")
+					d.ForceNew("sku")
+				}
+				if strings.EqualFold(newSku.(string), string(namespaces.SkuTierPremium)) {
+					zoneRedundant := d.Get("zone_redundant").(bool)
+					if !zoneRedundant {
+						return fmt.Errorf("zone_redundant needs to be set to true when using premium SKU")
+					}
+				}
+			}
+			return nil
+		}),
 	}
 }
 
diff --git a/azurerm/internal/services/eventhub/eventhub_namespace_resource_test.go b/azurerm/internal/services/eventhub/eventhub_namespace_resource_test.go
index 11dacb7223fa..693e1264c7cc 100644
--- a/azurerm/internal/services/eventhub/eventhub_namespace_resource_test.go
+++ b/azurerm/internal/services/eventhub/eventhub_namespace_resource_test.go
@@ -388,6 +388,14 @@ func TestAccEventHubNamespace_BasicWithSkuUpdate(t *testing.T) {
 				check.That(data.ResourceName).Key("capacity").HasValue("2"),
 			),
 		},
+		{
+			Config: r.premium(data),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+				check.That(data.ResourceName).Key("sku").HasValue("Premium"),
+				check.That(data.ResourceName).Key("capacity").HasValue("1"),
+			),
+		},
 	})
 }
 
@@ -588,6 +596,28 @@ resource "azurerm_eventhub_namespace" "test" {
 `, data.RandomInteger, data.Locations.Primary, data.RandomInteger)
 }
 
+func (EventHubNamespaceResource) premium(data acceptance.TestData) string {
+	return fmt.Sprintf(`
+provider "azurerm" {
+  features {}
+}
+
+resource "azurerm_resource_group" "test" {
+  name     = "acctestRG-eh-%d"
+  location = "%s"
+}
+
+resource "azurerm_eventhub_namespace" "test" {
+  name                = "acctesteventhubnamespace-%d"
+  location            = azurerm_resource_group.test.location
+  resource_group_name = azurerm_resource_group.test.name
+  sku                 = "Premium"
+  capacity            = "1"
+  zone_redundant      = true
+}
+`, data.RandomInteger, data.Locations.Primary, data.RandomInteger)
+}
+
 func (EventHubNamespaceResource) standardWithIdentity(data acceptance.TestData) string {
 	return fmt.Sprintf(`
 provider "azurerm" {
diff --git a/website/docs/r/eventhub_namespace.html.markdown b/website/docs/r/eventhub_namespace.html.markdown
index 96af0b2b7d58..4cd7e95ce6df 100644
--- a/website/docs/r/eventhub_namespace.html.markdown
+++ b/website/docs/r/eventhub_namespace.html.markdown
@@ -41,7 +41,7 @@ The following arguments are supported:
 
 * `location` - (Required) Specifies the supported Azure location where the resource exists. Changing this forces a new resource to be created.
 
-* `sku` - (Required) Defines which tier to use. Valid options are `Basic` and `Standard`.
+* `sku` - (Required) Defines which tier to use. Valid options are `Basic`, `Standard`, and `Premium`. Please not that setting this field to `Premium` will force the creation of a new resource and also requires setting `zone_redundant` to true.
 
 * `capacity` - (Optional) Specifies the Capacity / Throughput Units for a `Standard` SKU namespace. Default capacity has a maximum of `20`, but can be increased in blocks of 20 on a committed purchase basis.