dnsmasq_dns_servers cannot be set as DNS forwarders for dhcp agent's dnsmasq

[Nobuto Murata]

Now that the neutron-api charm accepts enable-ml2-dns=true and dns-domain, internal name resolution of instance names works. However, I'd like to leverage the dnsmasq to get external name as well such as google.com.

To achieve that, Neutron has a config option as dnsmasq_dns_servers in dhcp_agent.ini. But currently we cannot add the config through charm configuration.

[neutron/conf/agent/dhcp.py]
    cfg.ListOpt('dnsmasq_dns_servers',
                default=[],
                help=_('Comma-separated list of the DNS servers which will be '
                       'used as forwarders.')),

A workaround is to set "dnsmasq-flags" in neutron-gateway charm like dnsmasq-flags='server=8.8.8.8,server=8.8.4.4', but only one of two servers will be written in /etc/neutron/dnsmasq.conf.

It would be nice if either neutron-api or neutron-gateway charm expose dnsmasq_dns_servers option.

[Billy Olsen (billy-olsen)]

This should have been implemented and included as part of the internal-dns spec [0] but was missed in implementation.

https://specs.openstack.org/openstack/charm-specs/specs/pike/approved/internal-dns.html

[Billy Olsen (billy-olsen)]

Uploaded patchsets:

charm-neutron-gateway - https://review.openstack.org/#/c/499696/
charm-neutron-openvswitch - https://review.openstack.org/#/c/499697/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/499697
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-openvswitch/commit/?id=460602489dbc980776d116f3cc81716a88567ca0
Submitter: Jenkins
Branch: master

commit 460602489dbc980776d116f3cc81716a88567ca0
Author: Billy Olsen <email address hidden>
Date: Thu Aug 31 09:06:53 2017 -0700

    Add dns-nameservers config option for upstream dns servers

    Adds a dns-servers config option for specifying the forwarding
    dns servers to be used by the dnsmasq services on the neutron
    dhcp agent. This enables services using internal dns to also
    specify the forwarding dns servers in order to resolve hosts
    outside of the neutron network space.

    Note: this option only takes effect when the
    enable-local-dhcp-and-metadata flag is set to True.

    Change-Id: I510d163dd9738477b15497b25266e73a50368539
    Implements: blueprint internal-dns
    Closes-Bug: #1713721

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/499696
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-gateway/commit/?id=2b2c4b745f74fab39c8be85ffe124035ee001bdb
Submitter: Jenkins
Branch: master

commit 2b2c4b745f74fab39c8be85ffe124035ee001bdb
Author: Billy Olsen <email address hidden>
Date: Thu Aug 31 08:52:49 2017 -0700

    Add dns-servers config option for upstream dns servers

    Adds a dns-servers config option for specifying the forwarding
    dns servers to be used by the dnsmasq services on the neutron
    dhcp agent. This enables services using internal dns to also
    specify the forwarding dns servers in order to resolve hosts
    outside of the neutron network space.

    Change-Id: I3cd608b1491a45f565d5147894b8285e638eeaa7
    Implements: blueprint internal-dns
    Closes-Bug: #1713721