Set default value for dnsmasq_local_resolv to False

[OpenStack Infra]

https://review.openstack.org/269822
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.
Your project "openstack/neutron" is set up so that we directly report the documentation bugs against it. If this needs changing, the docimpact-group option needs to be added for the project. You can ask the OpenStack infra team (#openstack-infra on freenode) for help if you need to.

commit 003091a97480f12ea2fe948b6b9d8b4646d9463f
Author: armando-migliaccio <email address hidden>
Date: Tue Jan 19 11:25:05 2016 -0800

    Set default value for dnsmasq_local_resolv to False

    patch 0de1d8d4c introduced a new behavior whereby dnsmasq can rely
    on dns resolvers defined in the host's resolv.conf, and it did
    that by default.

    However this may introduce dns timeouts if the dns servers
    are not reachable for whatever reason. This may be especially
    likely in certain gate configurations (where the VM under test
    is a guest itself).

    Regardless of the root-cause analysis, this option should have
    defaulted to False to preserve backward compatibility, therefore
    this patch restores the old behavior in a way that local DNS
    resolution occurs only if the new option variable is set to
    True, or the admin has not explicitly set the list of DNS
    servers to be injected in the DHCP response.

    DocImpact: document how to configure DNS resolution by dnsmasq

    Change-Id: I90ab26bfa83c2d23c92110b8da73ef771e11f7bb

[Matt Kassawara (ionosphere80)]

The networking guide currently lacks information regarding DNS resolution for instances, so I think we should create a config-dns-resolution.rst file and populate it with the following methods:

1) To enable DNS resolution for instances on all neutron networks using the same one or more DNS resolvers, edit the dhcp_agent.ini file and set the dnsmasq_dns_servers option accordingly.

2) To enable DNS resolution for instances all neutron networks using DNS resolvers on the host (in /etc/resolv.conf) running the DHCP agent, edit the dhcp_agent.ini file and enable the dnsmasq_local_resolv option. Use with caution as this method can potentially leak internal DNS records.

3) To enable DNS resolution for instances on on individual networks, use the --dns-nameserver option with the neutron subnet-create command.

Add the file to the TOC in config.rst and I'll also reference it in the deployment scenarios.

[Matt Kassawara (ionosphere80)]

Also, we should backport this patch to Mitaka and Liberty.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/315415

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/315415
Committed: https://git.openstack.org/cgit/openstack/openstack-manuals/commit/?id=f3eff8dfa9f3bce555de3950a0daefe1472ebfdf
Submitter: Jenkins
Branch: master

commit f3eff8dfa9f3bce555de3950a0daefe1472ebfdf
Author: Robin Cernin <email address hidden>
Date: Thu May 12 10:30:13 2016 +0200

    [network] Configure DNS resolution

    Configure DNS resolution for instances.

    Closes-Bug: #1541192
    backport: mitaka
    Co-Authored-By: Matt Kassawara <email address hidden>

    Change-Id: I7e536291bb0966969b3153481c734f71cb3cad5f

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/319047

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/319047
Committed: https://git.openstack.org/cgit/openstack/openstack-manuals/commit/?id=41d65e5458b98f08323b03a288e2aecf6b92ffea
Submitter: Jenkins
Branch: stable/mitaka

commit 41d65e5458b98f08323b03a288e2aecf6b92ffea
Author: Robin Cernin <email address hidden>
Date: Thu May 12 10:30:13 2016 +0200

    [network] Configure DNS resolution

    Configure DNS resolution for instances.

    Closes-Bug: #1541192

    Co-Authored-By: Matt Kassawara <email address hidden>

    Change-Id: I7e536291bb0966969b3153481c734f71cb3cad5f
    (cherry picked from commit f3eff8dfa9f3bce555de3950a0daefe1472ebfdf)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/openstack-manuals 15.0.0 release.