Fix up how we memcache on py3

Previously, we stored the WSGI strings in memcached and returned them when
responding to get_account/container_info calls. This would lead to cache
corruption in a heterogenous py2/py3 cluster such as you would have during
a rolling upgrade.

Now, only store and return native strings.

Change-Id: I8d6f66dfe846493972e433f70bad76a33d204562

swift/common/memcached.py

@@ -138,7 +138,7 @@ class MemcacheConnPool(Pool):
         sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
         with Timeout(self._connect_timeout):
             sock.connect(sockaddr)
-        return (sock.makefile(), sock)
+        return (sock.makefile('rwb'), sock)
 
     def get(self):
         fp, sock = super(MemcacheConnPool, self).get()

swift/proxy/controllers/base.py

@@ -123,7 +123,8 @@ def _prep_headers_to_info(headers, server_type):
     sysmeta = {}
     other = {}
     for key, val in dict(headers).items():
-        lkey = key.lower()
+        lkey = wsgi_to_str(key).lower()
+        val = wsgi_to_str(val) if isinstance(val, str) else val
         if is_user_meta(server_type, lkey):
             meta[strip_user_meta_prefix(server_type, lkey)] = val
         elif is_sys_meta(server_type, lkey):
@@ -450,8 +451,22 @@ def get_cache_key(account, container=None, obj=None):
     :param account: The name of the account
     :param container: The name of the container (or None if account)
     :param obj: The name of the object (or None if account or container)
-    :returns: a string cache_key
+    :returns: a (native) string cache_key
     """
+    if six.PY2:
+        def to_native(s):
+            if s is None or isinstance(s, str):
+                return s
+            return s.encode('utf8')
+    else:
+        def to_native(s):
+            if s is None or isinstance(s, str):
+                return s
+            return s.decode('utf8', 'surrogateescape')
+
+    account = to_native(account)
+    container = to_native(container)
+    obj = to_native(obj)
 
     if obj:
         if not (account and container):

test/unit/common/test_memcached.py

@@ -19,6 +19,7 @@
 from collections import defaultdict
 import errno
 from hashlib import md5
+import io
 import six
 import socket
 import time
@@ -206,6 +207,9 @@ class TestMemcached(unittest.TestCase):
             while one or two:  # Run until we match hosts one and two
                 key = uuid4().hex.encode('ascii')
                 for conn in memcache_client._get_conns(key):
+                    if 'b' not in getattr(conn[1], 'mode', ''):
+                        self.assertIsInstance(conn[1], (
+                            io.RawIOBase, io.BufferedIOBase))
                     peeripport = '%s:%s' % conn[2].getpeername()
                     self.assertTrue(peeripport in (sock1ipport, sock2ipport))
                     if peeripport == sock1ipport:

test/unit/proxy/controllers/test_base.py

@@ -25,7 +25,8 @@ from swift.proxy.controllers.base import headers_to_container_info, \
     headers_to_account_info, headers_to_object_info, get_container_info, \
     get_cache_key, get_account_info, get_info, get_object_info, \
     Controller, GetOrHeadHandler, bytes_to_skip
-from swift.common.swob import Request, HTTPException, RESPONSE_REASONS
+from swift.common.swob import Request, HTTPException, RESPONSE_REASONS, \
+    bytes_to_wsgi
 from swift.common import exceptions
 from swift.common.utils import split_path, ShardRange, Timestamp
 from swift.common.header_key_dict import HeaderKeyDict
@@ -73,6 +74,8 @@ class ContainerResponse(FakeResponse):
     base_headers = {
         'x-container-object-count': 1000,
         'x-container-bytes-used': 6666,
+        'x-versions-location': bytes_to_wsgi(
+            u'\U0001F334'.encode('utf8')),
     }
 
 
@@ -353,6 +356,10 @@ class TestFuncs(unittest.TestCase):
         self.assertEqual(resp['storage_policy'], 0)
         self.assertEqual(resp['bytes'], 6666)
         self.assertEqual(resp['object_count'], 1000)
+        expected = u'\U0001F334'
+        if six.PY2:
+            expected = expected.encode('utf8')
+        self.assertEqual(resp['versions'], expected)
 
     def test_get_container_info_no_account(self):
         app = FakeApp(statuses=[404, 200])
@@ -382,10 +389,11 @@ class TestFuncs(unittest.TestCase):
         self.assertEqual(resp['bytes'], 3333)
         self.assertEqual(resp['object_count'], 10)
         self.assertEqual(resp['status'], 404)
-        if six.PY3:
-            self.assertEqual(resp['versions'], u'\U0001f4a9')
-        else:
-            self.assertEqual(resp['versions'], "\xf0\x9f\x92\xa9")
+        expected = u'\U0001F4A9'
+        if six.PY2:
+            expected = expected.encode('utf8')
+        self.assertEqual(resp['versions'], expected)
+
         for subdict in resp.values():
             if isinstance(subdict, dict):
                 self.assertEqual([(k, type(k), v, type(v))
@@ -393,6 +401,25 @@ class TestFuncs(unittest.TestCase):
                                  [(k, str, v, str)
                                   for k, v in subdict.items()])
 
+    def test_get_cache_key(self):
+        self.assertEqual(get_cache_key("account", "cont"),
+                         'container/account/cont')
+        self.assertEqual(get_cache_key(b"account", b"cont", b'obj'),
+                         'object/account/cont/obj')
+        self.assertEqual(get_cache_key(u"account", u"cont", b'obj'),
+                         'object/account/cont/obj')
+
+        # Expected result should always be native string
+        expected = u'container/\N{SNOWMAN}/\U0001F334'
+        if six.PY2:
+            expected = expected.encode('utf8')
+
+        self.assertEqual(get_cache_key(u"\N{SNOWMAN}", u"\U0001F334"),
+                         expected)
+        self.assertEqual(get_cache_key(u"\N{SNOWMAN}".encode('utf8'),
+                                       u"\U0001F334".encode('utf8')),
+                         expected)
+
     def test_get_container_info_env(self):
         cache_key = get_cache_key("account", "cont")
         req = Request.blank(