Allow change InstanceClass without replacing resource

aurora-mysql.cfhighlander.rb

@@ -20,16 +20,12 @@
     ComponentParam 'ReaderPromotionTier', 1, allowedValues: [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]
     ComponentParam 'BacktrackWindow', 0
 
-    if engine_mode == 'provisioned'
-      ComponentParam 'WriterInstanceType'
-      ComponentParam 'ReaderInstanceType'
-    end
-
     if engine_mode == 'serverless' || engine_mode == 'serverlessv2'
       ComponentParam 'MaxCapacity', 2, allowedValues: [1, 2, 4, 8, 16, 32, 64, 128, 192, 256]
       ComponentParam 'MinCapacity', 2, allowedValues: [0, 0.5, 1, 2, 4, 8, 16, 32, 64, 128, 192, 256]
     end
-
+    ComponentParam 'WriterInstanceType'
+    ComponentParam 'ReaderInstanceType'
     ComponentParam 'KmsKeyId' if defined? kms_key_id
     ComponentParam 'VPCId', type: 'AWS::EC2::VPC::Id'
     ComponentParam 'SubnetIds', type: 'CommaDelimitedList'

aurora-mysql.cfndsl.rb

@@ -89,7 +89,8 @@
     Engine external_parameters[:engine]
     EngineVersion engine_version unless engine_version.nil?
 
-    EngineMode(external_parameters[:engine_mode] == 'serverlessv2' ? 'provisioned' : external_parameters[:engine_mode])
+    # The serverless engine mode only applies for Aurora Serverless v1 DB clusters. Aurora Serverless v1 no more supported.
+    EngineMode 'provisioned'
     EnableLocalWriteForwarding FnIf('EnableLocalWriteForwarding', true, Ref('AWS::NoValue'))
 
     PreferredMaintenanceWindow maintenance_window unless maintenance_window.nil?
@@ -128,55 +129,31 @@
     end
   }
 
-  if engine_mode == 'serverless' || engine_mode == 'serverlessv2'
-    RDS_DBInstance(:ServerlessDBInstance) {
-      DBParameterGroupName Ref(:DBInstanceParameterGroup)
-      Engine external_parameters[:engine]
-      DBInstanceClass 'db.serverless'
-      DBClusterIdentifier Ref(:DBCluster)
-      EnablePerformanceInsights Ref('EnablePerformanceInsights')
-      PerformanceInsightsRetentionPeriod FnIf('EnablePerformanceInsights', Ref('PerformanceInsightsRetentionPeriod'), Ref('AWS::NoValue'))
-      Tags tags
-    }
-
-    RDS_DBInstance(:ServerlessDBInstanceReader) {
-      Condition(:EnableReader)
-      DBParameterGroupName Ref(:DBInstanceParameterGroup)
-      Engine external_parameters[:engine]
-      DBInstanceClass 'db.serverless'
-      DBClusterIdentifier Ref(:DBCluster)
-      EnablePerformanceInsights Ref('EnablePerformanceInsights')
-      PerformanceInsightsRetentionPeriod FnIf('EnablePerformanceInsights', Ref('PerformanceInsightsRetentionPeriod'), Ref('AWS::NoValue'))
-      PromotionTier FnJoin('', ['0', Ref(:ReaderPromotionTier)])
-      Tags tags
-    }
-  else
-    RDS_DBInstance(:DBClusterInstanceWriter) {
-      DBSubnetGroupName Ref(:DBClusterSubnetGroup)
-      DBParameterGroupName Ref(:DBInstanceParameterGroup)
-      DBClusterIdentifier Ref(:DBCluster)
-      Engine external_parameters[:engine]
-      PubliclyAccessible 'false'
-      DBInstanceClass Ref(:WriterInstanceType)
-      EnablePerformanceInsights Ref('EnablePerformanceInsights')
-      PerformanceInsightsRetentionPeriod FnIf('EnablePerformanceInsights', Ref('PerformanceInsightsRetentionPeriod'), Ref('AWS::NoValue'))
-      Tags tags + [{ Key: 'Name', Value: FnJoin('-', [ Ref(:EnvironmentName), external_parameters[:component_name], 'writer-instance' ])}]
-    }
+  RDS_DBInstance(:DBClusterInstanceWriter) {
+    DBParameterGroupName Ref(:DBInstanceParameterGroup)
+    Engine external_parameters[:engine]
+    DBClusterIdentifier Ref(:DBCluster)
+    DBSubnetGroupName Ref(:DBClusterSubnetGroup)
+    EnablePerformanceInsights Ref('EnablePerformanceInsights')
+    PerformanceInsightsRetentionPeriod FnIf('EnablePerformanceInsights', Ref('PerformanceInsightsRetentionPeriod'), Ref('AWS::NoValue'))
+    Tags tags + [{ Key: 'Name', Value: FnJoin('-', [ Ref(:EnvironmentName), external_parameters[:component_name], 'writer-instance' ])}]
+    PubliclyAccessible 'false'
+    DBInstanceClass Ref(:WriterInstanceType)
+  }
 
-    RDS_DBInstance(:DBClusterInstanceReader) {
-      Condition(:EnableReader)
-      DBSubnetGroupName Ref(:DBClusterSubnetGroup)
-      DBParameterGroupName Ref(:DBInstanceParameterGroup)
-      DBClusterIdentifier Ref(:DBCluster)
-      Engine external_parameters[:engine]
-      PubliclyAccessible 'false'
-      DBInstanceClass Ref(:ReaderInstanceType)
-      EnablePerformanceInsights Ref('EnablePerformanceInsights')
-      PerformanceInsightsRetentionPeriod FnIf('EnablePerformanceInsights', Ref('PerformanceInsightsRetentionPeriod'), Ref('AWS::NoValue'))
-      PromotionTier FnJoin('', ['0', Ref(:ReaderPromotionTier)])
-      Tags tags + [{ Key: 'Name', Value: FnJoin('-', [ Ref(:EnvironmentName), external_parameters[:component_name], 'reader-instance' ])}]
-    }
-  end
+  RDS_DBInstance(:DBClusterInstanceReader) {
+    Condition(:EnableReader)
+    DBParameterGroupName Ref(:DBInstanceParameterGroup)
+    Engine external_parameters[:engine]
+    DBClusterIdentifier Ref(:DBCluster)
+    DBSubnetGroupName Ref(:DBClusterSubnetGroup)
+    EnablePerformanceInsights Ref('EnablePerformanceInsights')
+    PerformanceInsightsRetentionPeriod FnIf('EnablePerformanceInsights', Ref('PerformanceInsightsRetentionPeriod'), Ref('AWS::NoValue'))
+    Tags tags + [{ Key: 'Name', Value: FnJoin('-', [ Ref(:EnvironmentName), external_parameters[:component_name], 'reader-instance' ])}]
+    PubliclyAccessible 'false'
+    PromotionTier FnJoin('', ['0', Ref(:ReaderPromotionTier)])
+    DBInstanceClass Ref(:ReaderInstanceType)
+  }
 
   Route53_RecordSet(:DBHostRecord) {
     if external_parameters[:dns_format]