Add x-remove-versions-location for feature: disable versioning

We can set x-versions-location empty to remove this header in API, but
to keep consistent, we should allow x-remove-versions-location too. The
usage is post "x-remove-versions-locaion: x", just like ACL remove
headers.

Fixed: bug #1107592

Change-Id: I1271eec6401d4a0e8c1a7c2d63aeb8dfef00bf6d

doc/source/overview_object_versioning.rst

@@ -15,7 +15,7 @@ container where the versions are stored. It is recommended to use a different
 When data is ``PUT`` into a versioned container (a container with the
 versioning flag turned on), the existing data in the file is redirected to a
 new object and the data in the ``PUT`` request is saved as the data for the
-versioned object. The new object name (for the previous version) is 
+versioned object. The new object name (for the previous version) is
 ``<versions_container>/<length><object_name>/<timestamp>``, where ``length``
 is the 3-character zero-padded hexidecimal length of the ``<object_name>`` and
 ``<timestamp>`` is the timestamp of when the previous version was created.
@@ -75,3 +75,15 @@ gone::
         http://<storage_url>/container/myobject
     curl -i -H "X-Auth-Token: <token>" \
         http://<storage_url>/versions?prefix=008myobject/
+
+---------------------------------------------------
+How to Disable Object Versioning in a Swift Cluster
+---------------------------------------------------
+
+If you want to disable all functionality, set ``allow_versions`` back to
+``False`` in the container server config.
+
+Disable versioning a versioned container (x is any value except empty)::
+
+    curl -i -HPOST -H "X-Auth-Token: <token>" \
+        -H "X-Remove-Versions-Location: x" http://<storage_url>/container

swift/proxy/controllers/base.py

@@ -278,17 +278,18 @@ class Controller(object):
             if getattr(m, 'publicly_accessible', False):
                 self.allowed_methods.add(name)
 
+    def _x_remove_headers(self):
+        return []
+
     def transfer_headers(self, src_headers, dst_headers):
 
         st = self.server_type.lower()
         x_remove = 'x-remove-%s-meta-' % st
-        x_remove_read = 'x-remove-%s-read' % st
-        x_remove_write = 'x-remove-%s-write' % st
         x_meta = 'x-%s-meta-' % st
         dst_headers.update((k.lower().replace('-remove', '', 1), '')
                            for k in src_headers
                            if k.lower().startswith(x_remove) or
-                           k.lower() in (x_remove_read, x_remove_write))
+                           k.lower() in self._x_remove_headers())
 
         dst_headers.update((k.lower(), v)
                            for k, v in src_headers.iteritems()

swift/proxy/controllers/container.py

@@ -50,6 +50,12 @@ class ContainerController(Controller):
         self.account_name = unquote(account_name)
         self.container_name = unquote(container_name)
 
+    def _x_remove_headers(self):
+        st = self.server_type.lower()
+        return ['x-remove-%s-read' % st,
+                'x-remove-%s-write' % st,
+                'x-remove-versions-location']
+
     def clean_acls(self, req):
         if 'swift.clean_acl' in req.environ:
             for header in ('x-container-read', 'x-container-write'):

test/unit/proxy/test_server.py

@@ -437,6 +437,17 @@ class TestController(unittest.TestCase):
         self.read_acl = 'read_acl'
         self.write_acl = 'write_acl'
 
+    def test_transfer_headers(self):
+        src_headers = {'x-remove-base-meta-owner': 'x',
+                       'x-base-meta-size': '151M',
+                       'new-owner': 'Kun'}
+        dst_headers = {'x-base-meta-owner': 'Gareth',
+                       'x-base-meta-size': '150M'}
+        self.controller.transfer_headers(src_headers, dst_headers)
+        expected_headers = {'x-base-meta-owner': '',
+                            'x-base-meta-size': '151M'}
+        self.assertEquals(dst_headers, expected_headers)
+
     def check_account_info_return(self, partition, nodes, is_none=False):
         if is_none:
             p, n = None, None
@@ -4318,6 +4329,17 @@ class TestContainerController(unittest.TestCase):
                                             container_ring=FakeRing(),
                                             object_ring=FakeRing())
 
+    def test_transfer_headers(self):
+        src_headers = {'x-remove-versions-location': 'x',
+                       'x-container-read': '*:user'}
+        dst_headers = {'x-versions-location': 'backup'}
+        controller = swift.proxy.controllers.ContainerController(self.app,
+                                                                 'a', 'c')
+        controller.transfer_headers(src_headers, dst_headers)
+        expected_headers = {'x-versions-location': '',
+                            'x-container-read': '*:user'}
+        self.assertEqual(dst_headers, expected_headers)
+
     def assert_status_map(self, method, statuses, expected,
                           raise_exc=False, missing_container=False):
         with save_globals():