Initialize privsep root_helper command

Currently, when using the Cinder backend, Glance
tries to execute os-brick commands directly using
"privsep-helper".  They should be launched via
"glance-rootwrap".

Depends-On: Ib7923543862275629d86a0fa76baa88722493bad
Change-Id: I26d9474d4aadcc0e58e2fce746708f148138c71f

glance_store/_drivers/cinder.py

@@ -18,6 +18,7 @@ import hashlib
 import logging
 import math
 import os
+import shlex
 import socket
 import time
 
@@ -38,10 +39,12 @@ try:
     from cinderclient import exceptions as cinder_exception
     from cinderclient.v2 import client as cinderclient
     from os_brick.initiator import connector
+    from oslo_privsep import priv_context
 except ImportError:
     cinder_exception = None
     cinderclient = None
     connector = None
+    priv_context = None
 
 
 CONF = cfg.CONF
@@ -473,6 +476,7 @@ class Store(glance_store.driver.Store):
         attach_mode = 'rw' if mode == 'wb' else 'ro'
         device = None
         root_helper = get_root_helper()
+        priv_context.init(root_helper=shlex.split(root_helper))
         host = socket.gethostname()
         properties = connector.get_connector_properties(root_helper, host,
                                                         False, False)

glance_store/tests/unit/test_cinder_store.py

@@ -158,12 +158,14 @@ class TestCinderStore(base.StoreBaseTest,
                              kwargs['conn'])
             return fake_connector
 
+        root_helper = "sudo glance-rootwrap /etc/glance/rootwrap.conf"
         with mock.patch.object(cinder.Store,
                                '_wait_volume_status',
                                return_value=fake_volume), \
                 mock.patch.object(cinder, 'temporary_chown',
                                   side_effect=fake_chown), \
-                mock.patch.object(cinder, 'get_root_helper'), \
+                mock.patch.object(cinder, 'get_root_helper',
+                                  return_value=root_helper), \
                 mock.patch.object(connector, 'get_connector_properties'), \
                 mock.patch.object(connector.InitiatorConnector, 'factory',
                                   side_effect=fake_factory):

setup.cfg

@@ -62,6 +62,7 @@ cinder =
   python-cinderclient>=2.0.1 # Apache-2.0
   os-brick>=1.8.0 # Apache-2.0
   oslo.rootwrap>=5.0.0 # Apache-2.0
+  oslo.privsep>=1.9.0 # Apache-2.0
 
 [build_sphinx]
 source-dir = doc/source