Enable eventlet_backdoor to return port.

Instead of having no return initialize_if_enabled() will now
return the port being used for the backdoor. This will allow
the use of random ports (which is set with a backdoor_port
configuration option set to 0)

This will also enable nova to be able to switch to using the
version of eventlet_backdoor here instead of the copy in
nova.common which will require this change in nova.

Change-Id: I01b6966daba410d82281ba86b5d295313ec36c68

1 files changed, 5 insertions, 3 deletions

diff --git a/openstack/common/eventlet_backdoor.py b/openstack/common/eventlet_backdoor.py
index 242c371..b28a2c6 100644
--- a/openstack/common/eventlet_backdoor.py
+++ b/openstack/common/eventlet_backdoor.py
@@ -61,7 +61,7 @@ def initialize_if_enabled():
     }
 
     if CONF.backdoor_port is None:
-        return
+        return None
 
     # NOTE(johannes): The standard sys.displayhook will print the value of
     # the last expression and set it to __builtin__._, which overwrites
@@ -73,6 +73,8 @@ def initialize_if_enabled():
             pprint.pprint(val)
     sys.displayhook = displayhook
 
-    eventlet.spawn_n(eventlet.backdoor.backdoor_server,
-                     eventlet.listen(('localhost', CONF.backdoor_port)),
+    sock = eventlet.listen(('localhost', CONF.backdoor_port))
+    port = sock.getsockname()[1]
+    eventlet.spawn_n(eventlet.backdoor.backdoor_server, sock,
                      locals=backdoor_locals)
+    return port