Multinic-libvirt

• Launchpad Entry: NovaSpec:multinic-libvirt
• Created: Ilya Alekseyev
• Contributors: Eldar Nugaev, Ilya Alekseyev

Summary

We need support for multiple network interfaces per instance for libvirt. Our vision based on http://wiki.openstack.org/multi-nic specification. with some additions.

Release Note

Multiple NIC for libvirt allows users to have instances connected to several networks.

Design

Instances should be created with one NIC per network associated with project. we expect that we will have one NIC per project network. So we expect that we will have ability to add several networks to project. NB: if there is no network associated with project we will keep old behaviour (one of networks that is not associated to any project will be selected). Our vision should be synchronized with Trey Morris who is working on Xen miltinic blueprint: https://blueprints.launchpad.net/nova/+spec/multi-nic GD PoC branches: https://code.launchpad.net/~ilyaalekseyev/nova/libvirt-multinic-experemental

Implementation

Code Changes

I. DB model changes.

1. Add to DB model:

 ||Network Interface Card||
 ||   + id (PK) ||
 ||   + instance_id (FK - instance.id) ||
 ||   + mac_address ||
 ||   + network_id(FK) ||

 ||Network to project association||
 ||   + network_id (FK, PK)||
 ||   + project_id (FK, PK)||
 ||   + order (int) - for interface sorting in libvirt template cycle||
 ||   + deleted, created_at, deleted_at, ...||

1. DB model changes:

 ||Instance||
 ||- mac_address||
I. nova-manage changes
   nova-manage network associate <project id> <network cidr> [<order>]
   order is optional parameter, if not exists will be max(order in project)+1
   Example: nova-manage network associate project1 10.0.0.0/16
I. libvirt connection changes
   changes in libvirt_con.to_xml() propagate NIC data
I. firewall rules changes
   All firewall drivers would be changed to support multiple networks per instance. iptable rules should be changed.
I. network managers changes

1. FlatManager: open question - seems it is not required to be changed, but we need to check it
2. FlatDHCPManager should be changed to support multiple networks
3. VlanManager should be changed to support multiple networks

I. template changes
  Add support of several NICs to template:
  

#!highlight xml
#for $nic in $nics
        <interface type='bridge'>
            <source bridge='$nic.bridge_name'/>
            <mac address='$nic.mac_address'/>
            <!--   <model type='virtio'/>  CANT RUN virtio network right now -->
            <filterref filter="nova-instance-$nic.name">
                <parameter name="IP" value="$nic.ip_address" />
                <parameter name="DHCPSERVER" value="$nic.dhcp_server" />           
#if $getVar('extra_params', False)
                $nic.extra_params
#end if
#if $getVar('ra_server', False)
                <parameter name="RASERVER" value="$nic.ra_server" />
#end if
            </filterref>
        </interface>
#end for

I. API changes:
   we not expecting any changes in EC2 API. we think that we could change OpenStack API only.

Test/Demo Plan

We need both unit and integration tests. Second is more important.

BoF agenda and discussion

http://ietherpad.com/arRVMd2Lwl

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