s3api: Better handle 503s in get_container_info, too

Change-Id: I269a59559a943fbf2781224d6962b25f6e07d30c
Related-Change: Iadb0a40092b8347eb5c04785cc14d1324cc9396f

swift/common/middleware/s3api/s3request.py

@@ -1485,8 +1485,10 @@ class S3Request(swob.Request):
         info = get_container_info(sw_req.environ, app, swift_source='S3')
         if is_success(info['status']):
             return info
-        elif info['status'] == 404:
+        elif info['status'] == HTTP_NOT_FOUND:
             raise NoSuchBucket(self.container_name)
+        elif info['status'] == HTTP_SERVICE_UNAVAILABLE:
+            raise ServiceUnavailable()
         else:
             raise InternalError(
                 'unexpected status code %d' % info['status'])

test/unit/common/middleware/s3api/test_s3request.py

@@ -31,7 +31,7 @@ from test.unit.common.middleware.s3api.test_s3api import S3ApiTestCase
 from swift.common.middleware.s3api.s3request import S3Request, \
     S3AclRequest, SigV4Request, SIGV4_X_AMZ_DATE_FORMAT, HashingInput
 from swift.common.middleware.s3api.s3response import InvalidArgument, \
-    NoSuchBucket, InternalError, \
+    NoSuchBucket, InternalError, ServiceUnavailable, \
     AccessDenied, SignatureDoesNotMatch, RequestTimeTooSkewed, BadDigest
 from swift.common.utils import md5
 
@@ -332,7 +332,8 @@ class TestRequest(S3ApiTestCase):
                 self.assertEqual(204, info['status'])  # sanity
             self.assertEqual(10, mock_info.call_count)
 
-        expected_errors = [(404, NoSuchBucket), (0, InternalError)]
+        expected_errors = [(404, NoSuchBucket), (0, InternalError),
+                           (503, ServiceUnavailable)]
         for status, expected_error in expected_errors:
             with patch('swift.common.middleware.s3api.s3request.'
                        'get_container_info',