[ovs-dev] [PATCH RFC] ovn: distributed logical port for VM metadata access

[Ramu Ramamurthy]

> This is an interesting proposal.  The alternative, which strikes me as a
> terrible idea, would be to somehow implement a TCP/IP stack and HTTP
> server inside OVS.
>
> Does there need to be a single metadata server per hypervisor, or one
> per logical switch per hypervisor?
>

Ben, Thanks for your review, and feedback.

The metadata-proxy-server is one per logical-switch that has at least
1 VM on the hypervisor.
In the worst case, there may be one metadata-proxy-server per VM on
the hypervisor
if each VM belonged to a different logical switch.

The metadata-proxy-server forwards the http request from the VM after
setting a few http headers -
one of the http-headers is the VMs IP address which is obtained from
the http request,
and the other http header is the network-id which comes from the
configuration of the process.
As such, the metadata-proxy-server is expected to be a lightweight process.

> I think that a lot of the commit message (include some bits that I
> snipped) should go into documentation.
>
> I feel like this needs to be properly evaluated by someone who
> understands OpenStack and Neutron better than me.  Maybe Russell?