azurerm_cosmosdb_mongo_collection - correctly read the _id index back when mongo 3.6

azurerm/internal/services/cosmos/cosmosdb_mongo_collection_resource.go

@@ -279,6 +279,7 @@ func resourceArmCosmosDbMongoCollectionUpdate(d *schema.ResourceData, meta inter
 
 func resourceArmCosmosDbMongoCollectionRead(d *schema.ResourceData, meta interface{}) error {
 	client := meta.(*clients.Client).Cosmos.MongoDbClient
+	accClient := meta.(*clients.Client).Cosmos.DatabaseClient
 	ctx, cancel := timeouts.ForRead(meta.(*clients.Client).StopContext, d)
 	defer cancel()
 
@@ -301,6 +302,12 @@ func resourceArmCosmosDbMongoCollectionRead(d *schema.ResourceData, meta interfa
 	d.Set("resource_group_name", id.ResourceGroup)
 	d.Set("account_name", id.DatabaseAccountName)
 	d.Set("database_name", id.MongodbDatabaseName)
+
+	accResp, err := accClient.Get(ctx, id.ResourceGroup, id.DatabaseAccountName)
+	if err != nil {
+		return fmt.Errorf("reading Cosmos Account %q : %+v", id.DatabaseAccountName, err)
+	}
+	d.Set("database_name", id.MongodbDatabaseName)
 	if props := resp.MongoDBCollectionGetProperties; props != nil {
 		if res := props.Resource; res != nil {
 			d.Set("name", res.ID)
@@ -313,8 +320,16 @@ func resourceArmCosmosDbMongoCollectionRead(d *schema.ResourceData, meta interfa
 			for k := range res.ShardKey {
 				d.Set("shard_key", k)
 			}
+			accountIsVersion36 := false
+			if accProps := accResp.DatabaseAccountGetProperties; accProps != nil {
+				for _, v := range *accProps.Capabilities {
+					if *v.Name == "EnableMongo" {
+						accountIsVersion36 = true
+					}
+				}
+			}
 
-			indexes, systemIndexes, ttl := flattenCosmosMongoCollectionIndex(res.Indexes)
+			indexes, systemIndexes, ttl := flattenCosmosMongoCollectionIndex(res.Indexes, accountIsVersion36)
 			if err := d.Set("default_ttl_seconds", ttl); err != nil {
 				return fmt.Errorf("failed to set `default_ttl_seconds`: %+v", err)
 			}
@@ -399,7 +414,7 @@ func expandCosmosMongoCollectionIndex(indexes []interface{}, defaultTtl *int) *[
 	return &results
 }
 
-func flattenCosmosMongoCollectionIndex(input *[]documentdb.MongoIndex) (*[]map[string]interface{}, *[]map[string]interface{}, *int32) {
+func flattenCosmosMongoCollectionIndex(input *[]documentdb.MongoIndex, accountIsVersion36 bool) (*[]map[string]interface{}, *[]map[string]interface{}, *int32) {
 	indexes := make([]map[string]interface{}, 0)
 	systemIndexes := make([]map[string]interface{}, 0)
 	var ttl *int32
@@ -422,6 +437,13 @@ func flattenCosmosMongoCollectionIndex(input *[]documentdb.MongoIndex) (*[]map[s
 				systemIndex["unique"] = true
 
 				systemIndexes = append(systemIndexes, systemIndex)
+
+				if accountIsVersion36 {
+					index["keys"] = utils.FlattenStringSlice(v.Key.Keys)
+					index["unique"] = true
+					indexes = append(indexes, index)
+				}
+
 			case "DocumentDBDefaultIndex":
 				// Updating system index `DocumentDBDefaultIndex` is not a supported scenario.
 				systemIndex["keys"] = utils.FlattenStringSlice(v.Key.Keys)

azurerm/internal/services/cosmos/cosmosdb_mongo_collection_resource_test.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"testing"
 
+	"github.com/Azure/azure-sdk-for-go/services/preview/cosmos-db/mgmt/2020-04-01-preview/documentdb"
 	"github.com/hashicorp/terraform-plugin-sdk/helper/resource"
 	"github.com/hashicorp/terraform-plugin-sdk/terraform"
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/internal/acceptance"
@@ -179,6 +180,25 @@ func TestAccAzureRMCosmosDbMongoCollection_autoscale(t *testing.T) {
 	})
 }
 
+func TestAccAzureRMCosmosDbMongoCollection_ver36(t *testing.T) {
+	data := acceptance.BuildTestData(t, "azurerm_cosmosdb_mongo_collection", "test")
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { acceptance.PreCheck(t) },
+		Providers:    acceptance.SupportedProviders,
+		CheckDestroy: testCheckAzureRMCosmosDbMongoCollectionDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccAzureRMCosmosDbMongoCollection_ver36(data),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					testCheckAzureRMCosmosDbMongoCollectionExists(data.ResourceName),
+				),
+			},
+			data.ImportStep(),
+		},
+	})
+}
+
 func testCheckAzureRMCosmosDbMongoCollectionDestroy(s *terraform.State) error {
 	client := acceptance.AzureProvider.Meta().(*clients.Client).Cosmos.MongoDbClient
 	ctx := acceptance.AzureProvider.Meta().(*clients.Client).StopContext
@@ -343,3 +363,27 @@ resource "azurerm_cosmosdb_mongo_collection" "test" {
 }
 `, testAccAzureRMCosmosDbMongoDatabase_basic(data), data.RandomInteger)
 }
+
+func testAccAzureRMCosmosDbMongoCollection_ver36(data acceptance.TestData) string {
+	return fmt.Sprintf(`
+%[1]s
+
+resource "azurerm_cosmosdb_mongo_database" "test" {
+  name                = "acctest-%[2]d"
+  resource_group_name = azurerm_cosmosdb_account.test.resource_group_name
+  account_name        = azurerm_cosmosdb_account.test.name
+}
+
+resource "azurerm_cosmosdb_mongo_collection" "test" {
+  name                = "acctest-%[2]d"
+  resource_group_name = azurerm_cosmosdb_mongo_database.test.resource_group_name
+  account_name        = azurerm_cosmosdb_mongo_database.test.account_name
+  database_name       = azurerm_cosmosdb_mongo_database.test.name
+
+  index {
+    keys   = ["_id"]
+    unique = true
+  }
+}
+`, testAccAzureRMCosmosDBAccount_capabilities(data, documentdb.MongoDB, []string{"EnableMongo"}), data.RandomInteger)
+}