[Openstack] [Xen-API] nova-xcp-network plugin searching for a xapi0 interface

John Garbutt John.Garbutt at citrix.com
Mon Mar 19 18:00:54 UTC 2012


Hi,

Looks like the network configuration is not quite right.

Have a look at this, for an example of how things could look networking wise (when using DevStack and XenServer with two nics):
http://wiki.openstack.org/XenServer/XenXCPAndXenServer

The manuals have a good description, although it is a little KVM specific:
http://docs.openstack.org/trunk/openstack-compute/admin/content/configuring-flat-dhcp-networking.html

I suggested using DevStack because it is the best "documentation" for a working set of flags right now (yes, not ideal, we must fix that asap!). Take a look:
https://github.com/openstack-dev/devstack/blob/master/stack.sh#L291
Note the defaults in the nova code might work for KVM, but will not work for XenServer, so you will need to set those flags with more appropriate values.

Hope that helps,
John

-----Original Message-----
From: Thomas Goirand [mailto:thomas at goirand.fr] 
Sent: 19 March 2012 5:25
To: John Garbutt
Cc: Dave Scott; xen-api; PKG OpenStack; openstack at lists.launchpad.net
Subject: Re: [Xen-API] nova-xcp-network plugin searching for a xapi0 interface

On 03/20/2012 12:05 AM, John Garbutt wrote:
> This sounds a lot like a configuration issue with your guest network bridge. Are you OK to supply your nova.conf file?

Sure! Here it is:

--sql_connection=mysql://nova:admin@127.0.0.1/nova
--novncproxy_base_url=http://<domU-IP>:6080/vnc_auto.html
--rabbit_host=<domU-IP>
--glance_api_servers=<domU-IP>:9292
--network_manager=nova.network.manager.VlanManager
--vlan_interface=br100
--dhcpbridge=/usr/bin/nova-dhcpbridge
--firewall_driver=nova.virt.xenapi.firewall.Dom0IptablesFirewallDriver
--connection_type=xenapi
--xenapi_connection_url=https://<dom0-ip>
--xenapi_connection_username=root
--xenapi_connection_password=XXXXXXX
--reboot_timeout=600
--rescue_timeout=86400
--resize_confirm_window=86400
--auth_strategy=keystone
--allow_admin_api
--allow_resize_to_same_host
--logdir=/var/log/nova
--state_path=/var/lib/nova
--lock_path=/var/lock/nova
--vncserver_listen=0.0.0.0
--force_dhcp_release
--use_deprecated_auth
--use_project_ca
--verbose

Note that since I restarted xcp-xapi, it seems that the xapi0 bridge is created each time I create a VM, which is what I was expecting. So that parts seems to work now, but the issue is that now, I have no networking at all (eg: I can't reach the instance from the Openstack domU).

Here's what "xe network-list" returns on my dom0:

uuid ( RO)                : <my-uuid>
          name-label ( RW): br100
    name-description ( RW): network for nova bridge br100
              bridge ( RO): xapi0

So it really is nova who created this. But shouldn't it be linked to my
xenbr0 as well? What is the normal networking setup that should be done?

There's absolutely zero documentation which I could find about this. Of course, I'll write one directly in our Debian packages as soon as this works.

> Also, have you tried using DevStack first? It is a good way to get the hang of how the flags work.

No it's not! DevStack is for testing with XenServer, and assumes that you'd be working with Ubuntu. Here, I'm testing the Debian packages that we are working on in Debian. Please don't direct me to DevStack, this wont help.

> I'm not familiar with the design of the Nova plugins but my guess is that they're trying to use the "Host internal management network" -- a network from which VMs can access the XenAPI (i.e. talk to xapi in domain 0).
> 
> On recent XCP versions the default bridge name changed to "xenapi" to make it easier to distinguish from a firewall rules PoV.

As per Mike on IRC, (from Citrix, upstream for XCP, XenServer and Kronos), each time there's a new network being created, XCP create a xapiX bridge automatically. I shouldn't have even try to bring the xapi0 bridge myself, XCP does it (if it doesn't, then there's an issue).

> Note that the actual linux bridge (or openvswitch) is created on demand so you won't see it in "brctl show" or "ovs-vsctl show" until it's being used.
> 
> Try changing "xapi0" to "xenapi" in the plugins and see if they work better?

Nop, that wont help, xapi0 is really what to expect. My only issue now is to have it connected to the br100 of Openstack in my domU.

Thanks for the help already,
Cheers,

Thomas




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