[ovirt-users] oVirt 3.5 & NAT

Mon Oct 27 14:10:34 UTC 2014

Darn, looks like this will not work :( the problem is that oVirt creates the bridge ovirtmgmt and binds that to your interface eg. em1.  So at that point you have network running.  If you then try to add that to the OVS stack your networking stop :(  I tried to add it as a port using ovs-vsctl add-port ovsbr0 ovirtmgmt which is accepted but then networking stops.  As soon as I remove again networking comes back to life.  There does not seem to be a way to have two co-existing bridges :( Thanks, Phil

----- Original Message -----
From: "Antoni Segura Puimedon" <asegurap at redhat.com>
To: "Phil Daws" <uxbod at splatnix.net>
Cc: "Dan Kenigsberg" <danken at redhat.com>, users at ovirt.org
Sent: Monday, 27 October, 2014 12:13:30 PM
Subject: Re: [ovirt-users] oVirt 3.5 & NAT

----- Original Message -----
> From: "Phil Daws" <uxbod at splatnix.net>
> To: "Antoni Segura Puimedon" <asegurap at redhat.com>
> Cc: "Dan Kenigsberg" <danken at redhat.com>, users at ovirt.org
> Sent: Monday, October 27, 2014 11:41:56 AM
> Subject: Re: [ovirt-users] oVirt 3.5 & NAT
> 
> Hi Antoni:
> 
> Yes, prior to the reboot it did work okay.  This is how it should look I
> believe:
> 
>     Bridge "ovirtmgmt"
>         Port "mgmt0"
>             Interface "mgmt0"
>                 type: internal
>         Port "ovsbr0"
>             Interface "ovsbr0"
>                 type: internal
> 
> So the bridge would be defined by oVirt then I guess with a custom hook that
> would then be added to the OVS stack ?

exactly! You could just make a hook script that runs an after_network_setup
hook that does the ovs-vsctl for you ;-)

Here you can see the presentation I gave last February at devconf about extending
with configurators and hooks.

http://blog.antoni.me/devconf14/#/8/1

I linked directly to a before_network_setup hook sample, because it works just like
the after_network_setup hook. Instead of logging to systemd, just add that if
'remove' is not in data and network == 'ovirtmgmt', it adds the network bridge to
the vswitch with python's subprocess.call or subprocess.check_output.

You can send it if you want me to take a look ;-)

PS: It is possible to write the hooks in bash, c, perl, etc. But we only have the
convenience read_json methods and such for python. If you wanted to, you could have
a simple bash hook that just checked if there was an ovirtmgmt bridge and it would
add it doing ovs-vsctl in the before_vdsm_start hooking point. That would have the
drawback that changing the ovirtmgmt bridge with oVirt UI would leave it disconnected
again.

> 
> Thanks, Phil
> 
> ----- Original Message -----
> From: "Antoni Segura Puimedon" <asegurap at redhat.com>
> To: "Phil Daws" <uxbod at splatnix.net>
> Cc: "Dan Kenigsberg" <danken at redhat.com>, users at ovirt.org
> Sent: Monday, 27 October, 2014 9:56:38 AM
> Subject: Re: [ovirt-users] oVirt 3.5 & NAT
> 
> 
> 
> ----- Original Message -----
> > From: "Phil Daws" <uxbod at splatnix.net>
> > To: "Antoni Segura Puimedon" <asegurap at redhat.com>
> > Cc: "Dan Kenigsberg" <danken at redhat.com>, users at ovirt.org
> > Sent: Monday, October 27, 2014 10:37:18 AM
> > Subject: Re: [ovirt-users] oVirt 3.5 & NAT
> > 
> > That is what I tried but oVirt appears to overwrite the bridge information
> > on
> > boot :( Thanks, Phil
> 
> But before rebooting, does it work as you intended? If so, you could just
> make
> a vdsm hook that adds ovirtmgmt to the ovs bridge after it is set up. (I
> could
> give more directions into how to do it).
> 
> > 
> > ----- Original Message -----
> > From: "Antoni Segura Puimedon" <asegurap at redhat.com>
> > To: "Phil Daws" <uxbod at splatnix.net>
> > Cc: "Dan Kenigsberg" <danken at redhat.com>, users at ovirt.org
> > Sent: Monday, 27 October, 2014 8:00:33 AM
> > Subject: Re: [ovirt-users] oVirt 3.5 & NAT
> > 
> > 
> > 
> > ----- Original Message -----
> > > From: "Phil Daws" <uxbod at splatnix.net>
> > > To: "Dan Kenigsberg" <danken at redhat.com>
> > > Cc: users at ovirt.org
> > > Sent: Saturday, October 25, 2014 5:02:59 PM
> > > Subject: Re: [ovirt-users] oVirt 3.5 & NAT
> > > 
> > > Hmmm, this is becoming difficult ..
> > > 
> > > I have added into the engine the custom hook and understand how that will
> > > work.  The issue is how can a single NIC use two different bridges ?
> > > Example with OVS would be that one requires:
> > > 
> > > em1 -+ ovirtmgmt (bridge) -> management IP (public)
> > >      + ovs       (bridge) -> firewall IP (public)
> > >                                 |
> > >                                 + vlan 1
> > >                                 + vlan 2
> > > 
> > > this works fine when using OVS and KVM, without oVirt, so there must be a
> > > way
> > > to hook the two together without a Neutron appliance.
> > > 
> > > Any thoughts ? Thanks, Phil.
> > 
> > I haven't tried this, and it may not work, but what happens if you add the
> > ovirtmgmt
> > bridge as a port of the ovs bridge?
> > > 
> > > 
> > > ----- Original Message -----
> > > From: "Dan Kenigsberg" <danken at redhat.com>
> > > To: "Phil Daws" <uxbod at splatnix.net>
> > > Cc: users at ovirt.org
> > > Sent: Wednesday, 22 October, 2014 3:54:46 PM
> > > Subject: Re: [ovirt-users] oVirt 3.5 & NAT
> > > 
> > > On Wed, Oct 22, 2014 at 03:12:09PM +0100, Phil Daws wrote:
> > > > Thanks Dan & Antoni:
> > > > 
> > > > I wonder then if I could replace the standard libvirt defined network
> > > > with
> > > > an OpenVSwitch one like I have on my dev system?  That is just straight
> > > > KVM with OVS integrated.  Maybe a bit more overhead in administration
> > > > but
> > > > possibly less than having to spin up a Neutron Appliance.
> > > 
> > > Once you start to use the vdsm-hook-extnet, all that you need to do is
> > > to replace the libvirt-side definition of the "external network". This
> > > may well be an OpenVSwitch-based network e.g.
> > > http://libvirt.org/formatnetwork.html#elementVlanTag
> > > _______________________________________________
> > > Users mailing list
> > > Users at ovirt.org
> > > http://lists.ovirt.org/mailman/listinfo/users
> > > 
> > 
> 