[vdsm] vdsm networking changes proposal

[Mark Wu]

On Thu 21 Feb 2013 04:46:16 PM CST, Mark Wu wrote:
> On 02/18/2013 05:23 PM, David Jaša wrote:
>> Hi,
>>
>> Alon Bar-Lev píše v Ne 17. 02. 2013 v 15:57 -0500:
>>> Hello Antoni,
>>>
>>> Great work!
>>> I am very excited we are going this route, it is first of many to
>>> allow us to be run on different distributions.
>>> I apologize I got to this so late.
>>>
>>> Notes for the model, I am unsure if someone already noted.
>>>
>>> I think that the abstraction should be more than entity and properties.
>>>
>>> For example:
>>>
>>> nic is a network interface
>>> bridge is a network interface and ports network interfaces
>>> bound is a network interface and slave network interfaces
>>> vlan is a network interface and vlan id
>>>
>>> network interface can have:
>>> - name
>>> - ip config
>>> - state
>>> - mtu
>>>
>>> this way it would be easier to share common code that handle pure
>>> interfaces.
>>>
>>> I don't quite understand the 'Team' configurator, are you suggesting
>>> a provider for each technology?
>> Team is a new implementation of bonding in Linux kernel IIRC.
>>
>>> bridge
>>> - iproute2 provider
>>> - ovs provider
>>> - ifcfg provider
>>>
>>> bond
>>> - iproute2
>>> - team
>>> - ovs
>>> - ifcfg
>>>
>>> vlan
>>> - iproute2
>>> - ovs
>>> - ifcfg
>>>
>>> So we can get a configuration of:
>>> bridge:iproute2
>>> bond:team
>>> vlan:ovs
>>>
>>> ?
>>>
>>> I also would like us to explore a future alternative of the network
>>> configuration via crypto vpn directly from qemu to another qemu, the
>>> idea is to have a kerberos like key per layer3(or layer2)
>>> destination, while communication is encrypted at user space and sent
>>> to a flat network. The advantage of this is that we manage logical
>>> network and not physical network, while relaying on hardware to find
>>> the best route to destination. The question is how and if we can
>>> provide this via the suggestion abstraction. But maybe it is too
>>> soon to address this kind of future.
>> Isn't it better to separate the two goals and persuade qemu
>> developers to implement TLS for migration connections?
> +1 for implementing it in qemu
>>
>> David
>>
>>> For the open questions:
>>>
>>> 1. Yes, I think that mode should be non-persistence, persistence
>>> providers should emulate non-persistence operations by diff between
>>> what they have and the goal.
>>>
>>> 2. Once vdsm is installed, the mode it runs should be fixed. So the
>>> only question is what is the selected profile during host deployment.
>>>
>>> 3. I think that if we can avoid aliases it would be nice.
>>>
>>> 4. Keeping the least persistence information would be flexible. I
>>> would love to see a zero persistence mode available, for example if
>>> management interface is dhcp or manually configured.
>>>
>>> I am very fond of the iproute2 configuration, and don't mind if
>>> administrator configures the management interface manually. I think
>>> this can supersede the ifcfg quite easily in most cases. In these
>>> rare cases administrator use ovirt to modify the network interface
>>> we may consider delegating persistence to totally different model.
>>> But as far as I understand the problem is solely related to the
>>> management connectivity, so we can implement a simple bootstrap of
>>> non-persistence module to reconstruct the management network setup
>>> from vdsm configuration instead of persisting it to the distribution
>>> width configuration.
>>>
>>> Regards,
>>> Alon Bar-Lev
>>>
>>> ----- Original Message -----
>>>> From: "Antoni Segura Puimedon" <asegurap at redhat.com>
>>>> To: arch at ovirt.org, vdsm-devel at fedorahosted.org
>>>> Sent: Friday, February 8, 2013 12:54:23 AM
>>>> Subject: vdsm networking changes proposal
>>>>
>>>> Hi fellow oVirters!
>>>>
>>>> The network team and a few others have toyed in the past with several
>>>> important
>>>> changes like using open vSwitch, talking D-BUS to NM, making the
>>>> network
>>>> non-persistent, etc.
>>>>
>>>> It is with some of this changes in mind that we (special thanks go to
>>>> Livnat
>>>> Peer, Dan Kenigsberg and Igor Lvovsky) have worked in a proposal for
>>>> a new architecture for vdsm's networking part. This proposal is
>>>> intended to
>>>> make our software more adaptable to new components and use cases,
>>>> eliminate
>>>> distro dependancies as much as possible and improve the
>>>> responsiveness and
>>>> scalability of the networking operations.
>>>>
>>>> To do so, it proposes an object oriented representation of the
>>>> different
>>>> elements that come into play in our networking use cases.
>>>>
>>>> But enough of introduction, please go to the feature page that we
>>>> have put
>>>> together and help us with your feedback, questions proposals and
>>>> extensions.
>>>>
>>>> http://www.ovirt.org/Feature/NetworkReloaded
>>>>
>>>>
>>>> Best regards,
>>>>
>>>> Toni
>>>> _______________________________________________
>>>> Arch mailing list
>>>> Arch at ovirt.org
>>>> http://lists.ovirt.org/mailman/listinfo/arch
>>>>
>>> _______________________________________________
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>
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Sorry for coming to it so late.  I get the following comments and 
questions about the proposal.

I suggest to add a field of top interface to the network, and only 
apply IpConfig and mtu to it.

For the openvswitch configurator,  it needs assistance of iproute2 
because it can't configure ip/netmask/gw and mtu.

I can't figure out the point to allow different configurators except 
openvswitch coexist. It could cause unnecessary complexity.

In the proposal, the rollback mechanism can be used to persist 
configuration for iproute2. Why do we still need NetworkManager?

I think the solution of "iproute2 + openvswitch + serializing 
configuration objects" can meet all our requirements. I remember that 
Dan had a concern of
adding a new standard about it in previous discussion. Have we already 
get agreement on it?

Mark