Cloudformation - EventBus support (#3052)

* add EventBus to model's map

* add support for creation of EventBus through cloudformation's api

* add cloudformation's delete

* add cloudformation's update

* add cloudformation's attribute

moto/cloudformation/parsing.py

@@ -96,6 +96,7 @@ MODEL_MAP = {
     "AWS::S3::Bucket": s3_models.FakeBucket,
     "AWS::SQS::Queue": sqs_models.Queue,
     "AWS::Events::Rule": events_models.Rule,
+    "AWS::Events::EventBus": events_models.EventBus,
 }
 
 UNDOCUMENTED_NAME_TYPE_MAP = {

moto/events/models.py

@@ -134,6 +134,52 @@ class EventBus(BaseModel):
 
         return json.dumps(policy)
 
+    def delete(self, region_name):
+        event_backend = events_backends[region_name]
+        event_backend.delete_event_bus(name=self.name)
+
+    def get_cfn_attribute(self, attribute_name):
+        from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
+
+        if attribute_name == "Arn":
+            return self.arn
+        elif attribute_name == "Name":
+            return self.name
+        elif attribute_name == "Policy":
+            return self.policy
+
+        raise UnformattedGetAttTemplateException()
+
+    @classmethod
+    def create_from_cloudformation_json(
+        cls, resource_name, cloudformation_json, region_name
+    ):
+        properties = cloudformation_json["Properties"]
+        event_backend = events_backends[region_name]
+        event_name = properties["Name"]
+        event_source_name = properties.get("EventSourceName")
+        return event_backend.create_event_bus(
+            name=event_name, event_source_name=event_source_name
+        )
+
+    @classmethod
+    def update_from_cloudformation_json(
+        cls, original_resource, new_resource_name, cloudformation_json, region_name
+    ):
+        original_resource.delete(region_name)
+        return cls.create_from_cloudformation_json(
+            new_resource_name, cloudformation_json, region_name
+        )
+
+    @classmethod
+    def delete_from_cloudformation_json(
+        cls, resource_name, cloudformation_json, region_name
+    ):
+        properties = cloudformation_json["Properties"]
+        event_backend = events_backends[region_name]
+        event_bus_name = properties["Name"]
+        event_backend.delete_event_bus(event_bus_name)
+
 
 class EventsBackend(BaseBackend):
     ACCOUNT_ID = re.compile(r"^(\d{1,12}|\*)$")
@@ -369,7 +415,7 @@ class EventsBackend(BaseBackend):
 
         return event_bus
 
-    def create_event_bus(self, name, event_source_name):
+    def create_event_bus(self, name, event_source_name=None):
         if name in self.event_buses:
             raise JsonRESTError(
                 "ResourceAlreadyExistsException",
@@ -406,7 +452,6 @@ class EventsBackend(BaseBackend):
             raise JsonRESTError(
                 "ValidationException", "Cannot delete event bus default."
             )
-
         self.event_buses.pop(name, None)
 
     def list_tags_for_resource(self, arn):