Support SNS subscription attributes (#1087)

* remove code for local test

* Add SNS set_subscription_attributes and get_subscription_attributes

moto/sns/models.py

@@ -13,7 +13,7 @@ from moto.core import BaseBackend, BaseModel
 from moto.core.utils import iso_8601_datetime_with_milliseconds
 from moto.sqs import sqs_backends
 from .exceptions import (
-    SNSNotFoundError, DuplicateSnsEndpointError, SnsEndpointDisabled
+    SNSNotFoundError, DuplicateSnsEndpointError, SnsEndpointDisabled, SNSInvalidParameter
 )
 from .utils import make_arn_for_topic, make_arn_for_subscription
 
@@ -76,6 +76,7 @@ class Subscription(BaseModel):
         self.endpoint = endpoint
         self.protocol = protocol
         self.arn = make_arn_for_subscription(self.topic.arn)
+        self.attributes = {}
 
     def publish(self, message, message_id):
         if self.protocol == 'sqs':
@@ -301,6 +302,26 @@ class SNSBackend(BaseBackend):
             raise SNSNotFoundError(
                 "Endpoint with arn {0} not found".format(arn))
 
+    def get_subscription_attributes(self, arn):
+        _subscription = [_ for _ in self.subscriptions.values() if _.arn == arn]
+        if not _subscription:
+            raise SNSNotFoundError("Subscription with arn {0} not found".format(arn))
+        subscription = _subscription[0]
+
+        return subscription.attributes
+
+    def set_subscription_attributes(self, arn, name, value):
+        if name not in ['RawMessageDelivery', 'DeliveryPolicy']:
+            raise SNSInvalidParameter('AttributeName')
+
+        # TODO: should do validation
+        _subscription = [_ for _ in self.subscriptions.values() if _.arn == arn]
+        if not _subscription:
+            raise SNSNotFoundError("Subscription with arn {0} not found".format(arn))
+        subscription = _subscription[0]
+
+        subscription.attributes[name] = value
+
 
 sns_backends = {}
 for region in boto.sns.regions():