[rdo-list] Access undercloud / overcloud vms via public ip addresses

[Dan Sneddon]

On 05/18/2016 01:53 AM, Edward Ahern wrote:
> Hi All,
> 
> I'm installing Openstack via tripleo-quickstart. Is it possible to assign ip addresses other than the defaults to the undercloud / overcloud vm's such that they are publicly accessible within our networks? 
> I have seen this to configure undercloud.conf: http://ucw-bnemec.rhcloud.com/
> But the undercloud vm itself is assigned a 192.168.23.x address so that also needs to be modified somewhere.
> 
> 
> 
> 
> Regards,
> 
> Ed
> 
> 
> 
> 
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The issue here isn't just one of IP addresses, but of connectivity. The
virt-host has IP connectivity to the Undercloud through virbr0, which
is the default libvirt bridge. The Undercloud nodes and Overcloud nodes
are connected to brbm, which is isolated.

I haven't tested this, but you might be able to add an external
interface to the brbm bridge to connect the VMs to an external network:

ovs-vsctl add-port brbm eth2

You would need to use a range of IP addresses for discovery and
deployment that are unused on that network, and there can't be an
external DHCP server on that network. Also, any clients on that network
which are configured for DHCP or PXE boot will suddenly start booting
into the discovery image, which might be really bad. Make sure that's
what you want before testing it out.

Another approach (also untested) might be to add an IP address on the
brbm bridge on the virt-host, and use that IP as the default gateway
for the ctlplane network. You could then configure IP forwarding on the
virt-host and create a static route pointing to the ctlplane subnet via
the virt-host.

-- 
Dan Sneddon         |  Principal OpenStack Engineer
dsneddon at redhat.com |  redhat.com/openstack
650.254.4025        |  dsneddon:irc   @dxs:twitter