[RFE] per-subnet DNS nameservers for ctlplane

[Harald Jensås]

Add a new option ``dns_nameservers`` in the subnet sections for the undercloud ctlplane network. By default the option is not set, and in that case the ``undercloud_nameservers`` are used, maintaining the current behaviour.

This decouples the nameservers used on the undercloud and the ones used for the overcloud nodes. In a DCN setting different DNS server may be preferred per-site.

It may also be useful to have a undercloud using IPv4 DNS servers, while the provisioning network is IPv6. We then need a way to specify IPv6 DNS servers for the ctlplane subnets so that overcloud nodes with IPv6 addresses can resolve names.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/668696

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/667380
Committed: https://git.openstack.org/cgit/openstack/python-tripleoclient/commit/?id=ee16c094472ee988b85aa81ce8fa9f5da8e61ad9
Submitter: Zuul
Branch: master

commit ee16c094472ee988b85aa81ce8fa9f5da8e61ad9
Author: Harald Jensås <email address hidden>
Date: Tue Jun 25 14:41:02 2019 +0200

    Allow per-subnet DNSNameServers for ctlplane network

    Add a new option ``dns_nameservers`` in the subnet sections
    for the undercloud ctlplane network. By default the option
    is not set, and in that case the ``undercloud_nameservers``
    are used, maintaining the current behaviour.

    This decouples the nameservers used on the undercloud and
    the ones used for the overcloud nodes. In a DCN setting
    different DNS server may be preferred per-site.

    Related-Bug: #1834306
    Change-Id: I0dc03eddf9ea00ff33cd3ae0cdc8f42a4961e89c

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/667381
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=dae0a89a80c5636a4b6d175501e009beb7071cf5
Submitter: Zuul
Branch: master

commit dae0a89a80c5636a4b6d175501e009beb7071cf5
Author: Harald Jensås <email address hidden>
Date: Tue Jun 25 15:26:07 2019 +0200

    Use per-subnet DNS nameservers for ctlplane

    Use the DNS nameservers for each ctlplane subnet,
    instead of using the same DNSServers for all subnets.

    Related-Bug: #1834306
    Depends-On: I0dc03eddf9ea00ff33cd3ae0cdc8f42a4961e89c
    Change-Id: I4c102d8f728a90cf9eb90f6129738377a8d2503c

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/667382
Committed: https://git.openstack.org/cgit/openstack/python-tripleoclient/commit/?id=f1450b3ae8036cfebdc1852ad11769e5585185d7
Submitter: Zuul
Branch: master

commit f1450b3ae8036cfebdc1852ad11769e5585185d7
Author: Harald Jensås <email address hidden>
Date: Tue Jun 25 16:21:08 2019 +0200

    Don't pass the DNSServers param in undercloud env

    Change I4c102d8f728a90cf9eb90f6129738377a8d2503c
    replaced use of the global DNSServers param, it now
    uses the per-subnet DnsNameServers instead.

    This is a cleanup to remove the now unused parameter.

    Closes-Bug: #1834306
    Depends-On: I4c102d8f728a90cf9eb90f6129738377a8d2503c
    Change-Id: I6e2e728d9e749867be0a90a4e54dce7b5318994c

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/668696
Committed: https://git.openstack.org/cgit/openstack/python-tripleoclient/commit/?id=a7dd7a6bbe94388fe73bdfedf47984e734183106
Submitter: Zuul
Branch: master

commit a7dd7a6bbe94388fe73bdfedf47984e734183106
Author: Harald Jensås <email address hidden>
Date: Tue Jul 2 17:24:05 2019 +0200

    Validate all or no subnets use dns_nameservers

    Follow up for https://review.opendev.org/667380

    Adds a validation to ensure that dns_nameservers
    are used for all subnets if used. If not subnets
    defines dns_nameservers they all fall back to
    use undercloud_nameservers which was has been the
    default for some time.

    Relates-Bug: #1834306
    Change-Id: I1cc1d20f8e15d531fb94b02c8d1313888fc8964d

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/python-tripleoclient 12.1.0 release.