Open Stack

There was 2 separate issues to resolve;

Firstly Nova was appending the default domain name .novalocal to the hostname it presents via the meta-data service. This can be resolved by setting dhcp_domain to an empty string in nova.conf on the Control node. For instance 'dhcp_domain='. An instances name can now be set to a FQDN which will then be passed cloud-init via the metadata server.

Secondly, The Neutron DHCP service sets the default DNS suffix for a NIC to openstacklocal . This causes delays in DNS lookups on external DNS servers, as the wrong domain is used by default. Similarly to the above, this can be resolve by setting 'dhcp_domain=' in the Neutron DHCP config file dhcp_agent.ini. Once this is set and the DHCP service restarted, the "--domain=<DOMAIN>" parameter no longer gets set
Oisin O'Malley
Systems Engineer
Iocane Pty Ltd
763 South Road
Black Forest SA 5035

Office:+61 (8) 8413 1010
Fax:+61 (8) 8231 2050
Email:oisin.omalley at iocane.com.au
Web:www.iocane.com.au

Better for business

on the DHCP agents dnsmasq and no default search suffix gets passed via DHCP.

Setting dns_domain Neutron network attribute, appears to do nothing at the moment.

Regards,
Oisin

>On 03/26/2017 11:49 PM, Matthew Taylor wrote:
> Responded off-list.
>
>For the benefit of the community, would one of you care to repeat the answer on-list please?
>
>Thanks!
>-jay
>
> On 27/3/17 14:22, Oisin O'Malley wrote:
>>>Hi All,
>>>
>>> What is the correct way to set an instances DNS search suffix via
>>> DHCP, currently all instances receive the default openstacklocal  DNS
>>> search space.  We are using OpenStack Newton with Neutron Networking.
>>>
>>> Setting dhcp_domain in dhcp_agent.ini will set the value globally for
>>> all networks, which is of little use as we host many Windows VMs with
>>> their own domains and DNS servers. Whatever is set as dhcp_domain is
>>> passed to Neutron DHCP Agent dnsmasq subprocess via a
>>> --domain=<DOMAIN> parameter.
>>>
>>> With the Neutron DNS extension enabled, you can set the a networks
>>> dns_domain attribute with "neutron net-update --dns-name", though
>>> this attribute appears to be ignored by the DHCP server. Can this be
>>> used to specify the DNS search space, if so how can it be configured?
>>> I need to be able to configure this on a per network/subnet level.
>>>
>>> Regards,
>>> Oisin
>>>
>>> Oisin O'Malley
>>> Systems Engineer
>>> Iocane Pty Ltd
>>> 763 South Road
>>> Black Forest SA 5035
>>>
>>> Office:+61 (8) 8413 1010
>>> Fax:+61 (8) 8231 2050
>>> Email:oisin.omalley at iocane.com.au
>>> Web:www.iocane.com.au