Open Stack

On 03/03/2014 11:32 PM, Dean Troyer wrote:
> On Mon, Mar 3, 2014 at 8:36 PM, Kyle Mestery <mestery at noironetworks.com
> <mailto:mestery at noironetworks.com>> wrote:
> 
>     In all cases today with Open Source plugins, Neutron agents have run
>     on the hosts. For OpenDaylight, this is not the case. OpenDaylight
>     integrates with Neutron as a ML2 MechanismDriver. But it has no
>     Neutron code on the compute hosts. OpenDaylight itself communicates
>     directly to those compute hosts to program Open vSwitch.
> 
>  
> 
>     devstack doesn't provide a way for me to express this today. On the
>     compute hosts in the above scenario, there is no "q-*" services
>     enabled, so the "is_neutron_enabled" function returns 1, meaning no
>     neutron.
> 
> 
> True and working as designed.
>  
> 
>     And then devstack sets Nova up to use nova-networking, which fails.
> 
> 
> This only happens if you have enabled nova-network.  Since it is on by
> default you must disable it.
>  
> 
>     The patch I have submitted [1] modifies "is_neutron_enabled" to
>     check for the meta neutron service being enabled, which will then
>     configure nova to use Neutron instead of nova-networking on the
>     hosts. If this sounds wonky and incorrect, I'm open to suggestions
>     on how to make this happen.
> 
> 
> From the review: 
> 
> is_neutron_enabled() is doing exactly what it is expected to do, return
> success if it finds any "q-*" service listed in ENABLED_SERVICES. If no
> neutron services are configured on a compute host, then this must not
> say they are.
> 
> Putting 'neutron' in ENABLED_SERVICES does nothing and should do nothing.
> 
> Since you are not implementing the ODS as a Neutron plugin (as far as
> DevStack is concerned) you should then treat it as a system service and
> configure it that way, adding 'opendaylight' to ENABLED_SERVICES
> whenever you want something to know it is being used.
> 
>  
> 
>     Note: I have another patch [2] which enables an OpenDaylight
>     service, including configuration of OVS on hosts. But I cannot check
>     if the "opendaylight" service is enabled, because this will only run
>     on a single node, and again, not on each compute host.
> 
> 
> I don't understand this conclusion. in multi-node each node gets its own
> specific ENABLED_SERVICES list, you can check that on each node to
> determine how to configure that node.  That is what I'm trying to
> explain in that last paragraph above, maybe not too clearly.

So in an Open Daylight environment... what's running on the compute host
to coordinate host level networking?

	-Sean

-- 
Sean Dague
Samsung Research America
sean at dague.net / sean.dague at samsung.com
http://dague.net

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