Fix ELB.describe_tags with multiple LoadBalancerNames.

moto/elb/responses.py

@@ -277,6 +277,7 @@ class ELBResponse(BaseResponse):
         return template.render()
 
     def describe_tags(self):
+        elbs = []
         for key, value in self.querystring.items():
             if "LoadBalancerNames.member" in key:
                 number = key.split('.')[2]
@@ -284,9 +285,10 @@ class ELBResponse(BaseResponse):
                 elb = self.elb_backend.get_load_balancer(load_balancer_name)
                 if not elb:
                     raise LoadBalancerNotFound(load_balancer_name)
+                elbs.append(elb)
 
         template = self.response_template(DESCRIBE_TAGS_TEMPLATE)
-        return template.render(tags=elb.tags)
+        return template.render(load_balancers=elbs)
 
 ADD_TAGS_TEMPLATE = """<AddTagsResponse xmlns="http://elasticloadbalancing.amazonaws.com/doc/2012-06-01/">
   <AddTagsResult/>
@@ -305,9 +307,11 @@ REMOVE_TAGS_TEMPLATE = """<RemoveTagsResponse xmlns="http://elasticloadbalancing
 DESCRIBE_TAGS_TEMPLATE = """<DescribeTagsResponse xmlns="http://elasticloadbalancing.amazonaws.com/doc/2012-06-01/">
   <DescribeTagsResult>
     <TagDescriptions>
+      {% for elb in load_balancers %}
       <member>
+        <LoadBalancerName>{{ elb.name }}</LoadBalancerName>
         <Tags>
-          {% for key, value in tags.items() %}
+          {% for key, value in elb.tags.items() %}
           <member>
             <Value>{{ value }}</Value>
             <Key>{{ key }}</Key>
@@ -315,6 +319,7 @@ DESCRIBE_TAGS_TEMPLATE = """<DescribeTagsResponse xmlns="http://elasticloadbalan
           {% endfor %}
         </Tags>
       </member>
+      {% endfor %}
     </TagDescriptions>
   </DescribeTagsResult>
   <ResponseMetadata>

tests/test_elb/test_elb.py

@@ -698,3 +698,23 @@ def test_add_remove_tags():
     tags.should.have.key('i').which.should.equal('b')
     tags.should.have.key('j').which.should.equal('c')
 
+
+    client.create_load_balancer(
+        LoadBalancerName='other-lb',
+        Listeners=[{'Protocol':'tcp', 'LoadBalancerPort':433, 'InstancePort':8433}],
+        AvailabilityZones=['us-east-1a', 'us-east-1b']
+    )
+
+    client.add_tags(LoadBalancerNames=['other-lb'],
+                    Tags=[{
+                       'Key': 'other',
+                       'Value': 'something'
+                    }])
+
+    lb_tags = { l['LoadBalancerName']: { d['Key']: d['Value'] for d in l['Tags'] } for l in client.describe_tags(LoadBalancerNames=['my-lb', 'other-lb'])['TagDescriptions'] }
+
+    lb_tags.should.have.key('my-lb')
+    lb_tags.should.have.key('other-lb')
+
+    lb_tags['my-lb'].shouldnt.have.key('other')
+    lb_tags['other-lb'].should.have.key('other').which.should.equal('something')