refresh db_instances tool

	modified:   builders.py
	modified:   plugins/refresh.py

botoform/builders.py

@@ -752,9 +752,15 @@ def finish_instance_roles(self, instance_role_cfg, instances=None):
 
     def db_instances(self, db_instance_cfg):
         """Build RDS DB Instances."""
+        existing_rds_names = self.evpc.rds.get_related_db_ids()
 
         for rds_name, db_cfg in db_instance_cfg.items():
 
+            if rds_name in existing_rds_names:
+                msg = 'skipping RDS db_instance: {} (it already exists)'
+                self.log.emit(msg.format(rds_name), 'debug')
+                continue
+
             self.log.emit('creating {} RDS db_instance ...'.format(rds_name))
 
             # make list of security group ids.

botoform/plugins/refresh.py

@@ -59,7 +59,7 @@ def instance_roles(args, evpc):
 
 def load_balancers(args, evpc):
     """
-    Refresh elb Load_balancers.
+    Refresh ELB load_balancers.
 
     :param args: The parsed arguments and flags from the CLI.
     :param evpc: An instance of :meth:`botoform.enriched.vpc.EnrichedVPC`.
@@ -69,6 +69,18 @@ def load_balancers(args, evpc):
     builder = get_builder_for_existing_vpc(evpc, args)
     builder.load_balancers(builder.config.get('load_balancers', no_cfg))
 
+def db_instances(args, evpc):
+    """
+    Refresh RDS db_instances.
+
+    :param args: The parsed arguments and flags from the CLI.
+    :param evpc: An instance of :meth:`botoform.enriched.vpc.EnrichedVPC`.
+
+    :returns: None
+    """
+    builder = get_builder_for_existing_vpc(evpc, args)
+    builder.db_instances(builder.config.get('db_instances', no_cfg))
+
 def private_zone(args, evpc):
     """
     Refresh private zone with new records / values.
@@ -135,6 +147,7 @@ def security_groups(args, evpc):
   'instance_roles'  : instance_roles,
   'security_groups' : security_groups,
   'load_balancers'  : load_balancers,
+  'db_instances'    : db_instances,
 }
 
 class Refresh(object):