Add a support for a default AWS event handler

README.md

@@ -615,6 +615,18 @@ def your_recurring_function(event, context):
 
 You can find more [example event sources here](http://docs.aws.amazon.com/lambda/latest/dg/eventsources.html).
 
+You can also respond to events dynamically using the `default_event_handler` setting, which can be useful for handling events from unknown sources or sources configured at run time:
+
+```javascript
+{
+  "production": {
+    ...,
+    "default_event_handler": "your_module.your_handler_function",
+    ...
+  }
+}
+```
+
 ## Asynchronous Task Execution
 
 Zappa also now offers the ability to seamlessly execute functions asynchronously in a completely separate AWS Lambda instance!

zappa/cli.py

@@ -2389,6 +2389,9 @@ def create_package(self, output=None):
                     event_mapping[arn] = function
             settings_s = settings_s + "AWS_EVENT_MAPPING={0!s}\n".format(event_mapping)
 
+            default_event_handler = self.stage_config.get('default_event_handler')
+            settings_s = settings_s + "AWS_DEFAULT_EVENT_HANDLER={0!r}\n".format(default_event_handler)
+
             # Map Lext bot events
             bot_events = self.stage_config.get('bot_events', [])
             bot_events_mapping = {}

zappa/handler.py

@@ -312,7 +312,7 @@ def get_function_for_aws_event(self, record):
             arn = record['s3']['bucket']['arn']
 
         if arn:
-            return self.settings.AWS_EVENT_MAPPING.get(arn)
+            return self.settings.AWS_EVENT_MAPPING.get(arn, self.settings.AWS_DEFAULT_EVENT_HANDLER)
 
         return None