Fix Python 3 support for eventlet monkey-patching2.5.0

Use eventlet.green.subprocess if eventlet is used and enable eventlet
tests on Python 3.

This change adds oslo_rootwrap.subprocess which is
eventlet.green.subprocess if eventlet monkey-patching is enabled or
if the TEST_EVENTLET environment variable is set, or subprocess of
the Python standard library otherwise.

When eventlet is used (with monkey-patching or not), it's more
reliable to use eventlet.green.subprocess instead of using directly
subprocess from the Python standard library.

On Python 2, it "works" to use directly subprocess: subprocess.Popen
calls os.pipe() and os.fdopen(fd) which are both monkey-patched. On
Python 3, it doesn't work because subprocess uses os.pipe() and
io.open(fd), and the io module is *not* monkey-patched at all.

Change-Id: Ib859bebe52612b35f0f1f53aedf76222683795e7

1 files changed, 3 insertions, 12 deletions

diff --git a/oslo_rootwrap/client.py b/oslo_rootwrap/client.py
index 6f7fd37..dec161e 100644
--- a/oslo_rootwrap/client.py
+++ b/oslo_rootwrap/client.py
@@ -16,24 +16,15 @@
 import logging
 from multiprocessing import managers
 from multiprocessing import util as mp_util
-import os
-import subprocess
 import threading
 import weakref
 
-try:
-    import eventlet.patcher
-except ImportError:
-    patched_socket = False
-else:
-    # In tests patching happens later, so we'll rely on environment variable
-    patched_socket = (eventlet.patcher.is_monkey_patched('socket') or
-                      os.environ.get('TEST_EVENTLET', False))
-
+import oslo_rootwrap
 from oslo_rootwrap import daemon
 from oslo_rootwrap import jsonrpc
+from oslo_rootwrap import subprocess
 
-if patched_socket:
+if oslo_rootwrap._patched_socket:
     # We have to use slow version of recvall with eventlet because of a bug in
     # GreenSocket.recv_into:
     # https://bitbucket.org/eventlet/eventlet/pull-request/41