From f28ad8ee293e239c0b743fcd8cfbb4617090811f Mon Sep 17 00:00:00 2001
From: Peter Van Bouwel <peter.vanbouwel@ipc.be>
Date: Tue, 11 Nov 2014 10:26:02 +0100
Subject: [PATCH] Alter get_tags to use the backend associated with the
 taggable object.  Also give volume and snapshot an additional backend
 attribute.

---
 moto/ec2/models.py          | 20 +++++++++++++++-----
 tests/test_ec2/test_tags.py |  4 ++--
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index 4684e02b3..8f9220142 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -109,7 +109,15 @@ class StateReason(object):
 
 class TaggedEC2Resource(object):
     def get_tags(self, *args, **kwargs):
-        tags = ec2_backend.describe_tags(filters={'resource-id': [self.id]})
+        if hasattr(self,"ec2_backend"):
+            backend = self.ec2_backend
+        elif hasattr(self,"ebs_backend"):
+            backend = self.ebs_backend
+        else:
+            raise NotImplementedError("Tagging of an object with backend that differs from ec2_backend or ebs_backend.")
+
+
+        tags = backend.describe_tags(filters={'resource-id': [self.id]})
         return tags
 
     def get_filter_value(self, filter_name):
@@ -1224,11 +1232,12 @@ class VolumeAttachment(object):
 
 
 class Volume(TaggedEC2Resource):
-    def __init__(self, volume_id, size, zone):
+    def __init__(self, ebs_backend, volume_id, size, zone):
         self.id = volume_id
         self.size = size
         self.zone = zone
         self.attachment = None
+        self.ebs_backend = ebs_backend
 
     @classmethod
     def create_from_cloudformation_json(cls, resource_name, cloudformation_json):
@@ -1253,11 +1262,12 @@ class Volume(TaggedEC2Resource):
 
 
 class Snapshot(TaggedEC2Resource):
-    def __init__(self, snapshot_id, volume, description):
+    def __init__(self, ebs_backend, snapshot_id, volume, description):
         self.id = snapshot_id
         self.volume = volume
         self.description = description
         self.create_volume_permission_groups = set()
+        self.ebs_backend = ebs_backend
 
 
 class EBSBackend(object):
@@ -1270,7 +1280,7 @@ class EBSBackend(object):
     def create_volume(self, size, zone_name):
         volume_id = random_volume_id()
         zone = self.get_zone_by_name(zone_name)
-        volume = Volume(volume_id, size, zone)
+        volume = Volume(self, volume_id, size, zone)
         self.volumes[volume_id] = volume
         return volume
 
@@ -1312,7 +1322,7 @@ class EBSBackend(object):
     def create_snapshot(self, volume_id, description):
         snapshot_id = random_snapshot_id()
         volume = self.get_volume(volume_id)
-        snapshot = Snapshot(snapshot_id, volume, description)
+        snapshot = Snapshot(self, snapshot_id, volume, description)
         self.snapshots[snapshot_id] = snapshot
         return snapshot
 
diff --git a/tests/test_ec2/test_tags.py b/tests/test_ec2/test_tags.py
index 15717519d..72e72fb86 100644
--- a/tests/test_ec2/test_tags.py
+++ b/tests/test_ec2/test_tags.py
@@ -315,8 +315,8 @@ def test_retrieved_snapshots_must_contain_their_tags():
     tag_key = 'Tag name'
     tag_value = 'Tag value'
     tags_to_be_set = {tag_key: tag_value}
-    conn = boto.connect_ec2('the_key', 'the_secret')
-    volume = conn.create_volume(80, "us-east-1a")
+    conn = boto.connect_ec2(aws_access_key_id='the_key', aws_secret_access_key='the_secret')
+    volume = conn.create_volume(80, "eu-west-1a")
     snapshot = conn.create_snapshot(volume.id)
     conn.create_tags([snapshot.id], tags_to_be_set)