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[Chris Behrens <cbehrens@xxxxxxxxxxxx>]

On Feb 23, 2012, at 3:55 PM, Justin Santa Barbara wrote:

> Thanks for chipping in.
> 
> I have contributed a patch (which has merged) which should allow you
> to stop editing the SQL:  https://review.openstack.org/#change,3816
> With that, you should be able to pass the full range, with an
> additional argument specifying the subset that nova controls:
> e.g.-fixed_cidr=10.200.0.0/16

Oh cool.. that'll save me some pain. :)

> 
> When I boot my VM, I think it gets a real address from my DHCP server
> (because the VM can reach the DHCP server), but not the address nova
> assigned it!  I believe the nova iptables rules mean that the machine
> can't then do TCP/IP, but even if I am wrong/could overcome that, I
> don't think cloud-init could then configure the correct address.

If you're going to go the cloud-init route... you wouldn't need DHCP, right?   There should be iptables rules to allow you to talk to the metadata service over 169.254.*  (And linux should give you a default link-local address that allows you to talk to the MD service magically)

Do you have a non-nova DHCP server running as well?

- Chris


> 
> Justin
> 
> 
> On Thu, Feb 23, 2012 at 3:38 PM, Chris Behrens <cbehrens@xxxxxxxxxxxx> wrote:
>> I'd assume FlatDHCPManager works much like FlatManager, but maybe I'm wrong.  I use FlatManager and I always end up having to modify the fixed_ips table manually after running nova-manage because I think I'm trying to do something similar as you.  I have a /23... and I want to give nova a /25 out of it.   Though I'm giving nova a /25, it's still really a /23.   I use nova-manage to add my /23 and then I edit the fixed_ips table and mark a lot of addresses as 'reserved'... or just remove them altogether.  (When I try to specify the /25 to nova-manage, it doesn't go so well)
>> 
>> As far as 169.254...  you can reach that without any address assigned.  Your NIC should receive a link local address when there's no other IP assigned.... which is in the 169.254.* range.
>> 
>> Not sure if that helped much :)
>> 
>> - Chris
>> 
>> On Feb 23, 2012, at 3:12 PM, Justin Santa Barbara wrote:
>> 
>>> I'm trying to use OpenStack in what I think to be the typical
>>> non-public-cloud deployment, and my experience is not what it
>>> could/should be.  I'm hoping someone can point me to the "right way",
>>> or we can figure out what needs to change.
>>> 
>>> My wishlist:
>>> * I want my instances to be on "my network" e.g. 10.0.0.0/16
>>> * As Nova can't pull IPs from my DHCP server, I'm willing to allocate
>>> it a sub-range, e.g. 10.200.0.0/16
>>> 
>>> First decision: Choosing a networking mode:
>>> * I don't want / need VLANs
>>> * If I use FlatDHCPManager, I can't do the subrange stuff - it seems
>>> that this mode assumes it controls the entire address range.
>>> * So it's FlatManager.  It works, but now I don't have DHCP, so I just
>>> have to inject info into the instance.
>>> 
>>> Next decision: How to inject info (at least the IP address):
>>> * Supposedly the 'right way' is to use cloud-init.  It looks like I'd
>>> still need DHCP before I can reach 169.254..., and I don't have that.
>>> It looks like cloud-init can't do network configuration even if nova
>>> passed the information in.  And I'd be locked into cloud-init images -
>>> no Windows, no Debian etc.
>>> * The next best way is config_drive.  It looks like I'd have to bundle
>>> my own image.  Maybe I could use cloud-init, maybe with an OVF
>>> formatted config_drive, but even then I couldn't configure networking
>>> (?)
>>> * So now I'm back to file injection.  That just works.
>>> 
>>> So now I'm using FlatManager and file injection; and yet I feel this
>>> is the dodgy back alley of OpenStack, and I should be in the well-lit
>>> nice area.  I worry that things like file injection and FlatManager
>>> are less favored and may be deprecated in future.  But every time I
>>> try to do things "right" I just waste a lot of time and make no
>>> progress.
>>> 
>>> Yet I feel I didn't really have a choice here.   How are other people
>>> making this work?  What is the "right way"?
>>> 
>>> Justin
>>> 
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>>