From 20d8318997dfd13bd700f458848679240fa3f8e1 Mon Sep 17 00:00:00 2001
From: Hugo Lopes Tavares <hltbra@gmail.com>
Date: Tue, 24 Feb 2015 17:56:26 -0500
Subject: [PATCH] Add support to tag filtering to Security Groups

---
 moto/ec2/models.py                     |  7 ++++++-
 tests/test_ec2/test_security_groups.py | 10 ++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index ac0bb4ddc..1336eedb8 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -92,7 +92,9 @@ from .utils import (
     filter_reservations,
     random_network_acl_id,
     random_network_acl_subnet_association_id,
-    random_vpn_gateway_id)
+    random_vpn_gateway_id,
+    is_tag_filter,
+)
 
 
 def validate_resource_ids(resource_ids):
@@ -1113,6 +1115,9 @@ class SecurityGroup(TaggedEC2Resource):
             for ingress in self.ingress_rules:
                 if getattr(ingress, ingress_attr) in filter_value:
                     return True
+        elif is_tag_filter(key):
+            tag_value = self.get_filter_value(key)
+            return tag_value in filter_value
         else:
             attr_name = to_attr(key)
             return getattr(self, attr_name) in filter_value
diff --git a/tests/test_ec2/test_security_groups.py b/tests/test_ec2/test_security_groups.py
index 861e492b8..e555bd694 100644
--- a/tests/test_ec2/test_security_groups.py
+++ b/tests/test_ec2/test_security_groups.py
@@ -248,3 +248,13 @@ def test_security_group_tagging():
     group = conn.get_all_security_groups("test-sg")[0]
     group.tags.should.have.length_of(1)
     group.tags["Test"].should.equal("Tag")
+
+
+@mock_ec2
+def test_security_group_tag_filtering():
+    conn = boto.connect_ec2()
+    sg = conn.create_security_group("test-sg", "Test SG")
+    sg.add_tag("test-tag", "test-value")
+
+    groups = conn.get_all_security_groups(filters={"tag:test-tag": "test-value"})
+    groups.should.have.length_of(1)