The flag is actually is defined twice.  I'm not sure why it is redefined in vmwareapi_net.py.

I'm not sure if this is a naming conflict or the author was simply trying to change the default value of the flag.  In any case, here is a possible fix:

=== modified file 'nova/network/vmwareapi_net.py'
--- nova/network/vmwareapi_net.py       2011-05-11 19:24:01 +0000
+++ nova/network/vmwareapi_net.py       2011-05-25 18:13:39 +0000
@@ -30,9 +30,7 @@
 
 
 FLAGS = flags.FLAGS
-flags.DEFINE_string('vlan_interface', 'vmnic0',
-                    'Physical network adapter name in VMware ESX host for '
-                    'vlan networking')
+FLAGS['vlan_interface'].SetDefault('vmnic0')
 
 
 def ensure_vlan_bridge(vlan_num, bridge, net_attrs=None):

Vish

On May 25, 2011, at 8:51 AM, Edouard Thuleau wrote:

> I try again with nova-compute rev1108 but the bug persists.
> 
> -- 
> You received this bug notification because you are a member of Nova Bug
> Team, which is subscribed to OpenStack Compute (nova).
> https://bugs.launchpad.net/bugs/787657
> 
> Title:
>  VMware vlan_interface flag defined txice
> 
> Status in OpenStack Compute (Nova):
>  Triaged
> 
> Bug description:
>  Hi,
> 
>  I use Nova (bzr1101) with an ESXi 4.1 hypervisor.
>  I set the flag 'vlan_interface' inm y configuration file but Nova didn't start and log says :
> 
> 
>  2011-05-24 18:10:38,728 ERROR nova [-] in Service.create()
>  (nova): TRACE: Traceback (most recent call last):
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/service.py", line 267, in serve
>  (nova): TRACE:     services = [Service.create()]
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/service.py", line 164, in create
>  (nova): TRACE:     report_interval, periodic_interval)
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/service.py", line 69, in __init__
>  (nova): TRACE:     self.manager = manager_class(host=self.host, *args, **kwargs)
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/compute/manager.py", line 132, in __init__
>  (nova): TRACE:     self.network_manager = utils.import_object(FLAGS.network_manager)
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/utils.py", line 73, in import_object
>  (nova): TRACE:     return cls()
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/network/manager.py", line 123, in __init__
>  (nova): TRACE:     self.driver = utils.import_object(network_driver)
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/utils.py", line 69, in import_object
>  (nova): TRACE:     __import__(import_str)
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/network/vmwareapi_net.py", line 34, in <module>
>  (nova): TRACE:     'Physical network adapter name in VMware ESX host for '
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/flags.py", line 215, in _wrapped
>  (nova): TRACE:     func(*args, **kw)
>  (nova): TRACE:   File "/usr/lib/python2.6/dist-packages/gflags.py", line 1808, in DEFINE_string
>  (nova): TRACE:     DEFINE(parser, name, default, help, flag_values, serializer, **args)
>  (nova): TRACE:   File "/usr/lib/python2.6/dist-packages/gflags.py", line 1701, in DEFINE
>  (nova): TRACE:     flag_values)
>  (nova): TRACE:   File "/usr/lib/python2.6/dist-packages/gflags.py", line 1716, in DEFINE_flag
>  (nova): TRACE:     fv[flag.name] = flag
>  (nova): TRACE:   File "/usr/lib/pymodules/python2.6/nova/flags.py", line 131, in __setitem__
>  (nova): TRACE:     gflags.FlagValues.__setitem__(self, name, flag)
>  (nova): TRACE:   File "/usr/lib/python2.6/dist-packages/gflags.py", line 791, in __setitem__
>  (nova): TRACE:     raise DuplicateFlagError(name, self)
>  (nova): TRACE: DuplicateFlagError: The flag 'vlan_interface' is defined twice. First from nova.network.manager, Second from nova.network.vmwareapi_net
>  (nova): TRACE: 
>  2011-05-24 18:10:38,750 CRITICAL nova [-] The flag 'vlan_interface' is defined twice. First from nova.network.manager, Second from nova.network.vmwareapi_net
> 
>  If I comment lines in source file 'nova/network/vmwareapi_net.py', it works correctly:
>      flags.DEFINE_string('vlan_interface', 'vmnic0',
>                           'Physical network adapter name in VMware ESX host for '
>                           'vlan networking')