suppress diff on encryption key name if the database instance is a re…

…plica (#5824) (#4130)

Signed-off-by: Modular Magician <magic-modules@google.com>

.changelog/5824.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+sql: fixed bug where permadiff of `encryption_key_name` would show on `google_sql_database_instance` for replica instances.
+```

google-beta/resource_sql_database_instance.go

@@ -83,6 +83,16 @@ var (
 	}
 )
 
+func diffSuppressSqlReplicaKeyName(k, old, new string, d *schema.ResourceData) bool {
+	if d.Get("replica_configuration") != nil {
+		// This is a replica and the config value must be null, but the API will
+		// return the key name of the master instance, so we'll suppress this diff
+		return true
+	}
+
+	return false
+}
+
 func resourceSqlDatabaseInstance() *schema.Resource {
 	return &schema.Resource{
 		Create: resourceSqlDatabaseInstanceCreate,
@@ -436,9 +446,10 @@ settings.backup_configuration.binary_log_enabled are both set to true.`,
 			},
 
 			"encryption_key_name": {
-				Type:     schema.TypeString,
-				Optional: true,
-				ForceNew: true,
+				Type:             schema.TypeString,
+				Optional:         true,
+				DiffSuppressFunc: diffSuppressSqlReplicaKeyName,
+				ForceNew:         true,
 			},
 
 			"root_password": {