No need for default DNS

[Steve McLellan]

NeutronNetwork requires a dns nameserver when it deploys a subnet. I can't see any reason to require it, nor configure a server-wide default. IIRC, if no nameserver list is provided to a neutron subnet, it uses the DHCP (gateway) address which in turn forwards to dnsmasq.

Unless i'm wrong about that, i suggest removing the `[networking]/default_dns` config option, and the useDefaultDNS flag from NeutronNetwork. If an explicit dns nameserver list is given, it can be added to the template, but the dns_nameservers attribute can otherwise be an empty list (the heat default).

A mandatory default can do more harm than good, since it means duplicating configuration details from the cloud to the murano configuration.

[bharaththiruveedula (bharath-ves)]

Actually I feel we don't need to pass any dns value to Heat. So do you
want me to totally remove the "default_dns" parameter or make it
optional i.e., if that option is there we pass it to heat otherwise we
don't?

[Serg Melikyan (smelikyan)]

I think we should remove this option completely

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/155397

[OpenStack Infra (hudson-openstack)]

Change abandoned by Ekaterina Chernova (<email address hidden>) on branch: master
Review: https://review.openstack.org/144327

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/155397
Committed: https://git.openstack.org/cgit/openstack/murano/commit/?id=ff9c0c49eaa53a054d4e2a847221a7bc797ffb92
Submitter: Jenkins
Branch: master

commit ff9c0c49eaa53a054d4e2a847221a7bc797ffb92
Author: Ekaterina Chernova <email address hidden>
Date: Thu Feb 12 19:31:48 2015 +0300

    Remove hardcoded dns from config file

    If no nameserver list is provided to a neutron subnet,
    it uses the DHCP (gateway) address which in turn forwards to dnsmasq.

    So dns_nameservers will be set to emptylist in heat templete.

    In case user wants to set different dns from default,
    he may edit the config parameter, witch is not removed.
    The name of parameters is changes to dns_nameservers (with s at the end)
    to correspond the same name in heat template.

    Change-Id: Iba8b12b8bc78f821e11debb58f20cb713a9dc9c7
    Closes-Bug: #1367877