[horizon] Allow custom local settings to be applied

[Jorge Niedbalski]

[Description]

kolla-ansible should provide a mechanism to allow operators to overwrite
the default (or not exposed through configuration) options for the local_settings.

local_settings.j2 may be good place to configure horizon but requires for the
operator to sync it on every release.

custom_local_settings.j2 can be used to overwrite things from local_settings.j2 without a need of syncing it first.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/567006
Committed: https://git.openstack.org/cgit/openstack/kolla/commit/?id=479daab59b4a1faad3a4ab5b7f6ecc4887ffea3a
Submitter: Zuul
Branch: master

commit 479daab59b4a1faad3a4ab5b7f6ecc4887ffea3a
Author: Jorge Niedbalski <email address hidden>
Date: Tue May 8 15:47:43 2018 -0300

    Create symlink if /e/o-d/customer_local_settings exists

    Create site-packages custom_local_settings symlink if /etc/openstack-dashboard/custom_
    local_settings exists, this will be used as a mechanism to extend the
    current local_settings without a need to change the file and rebuild
    the image

    Change-Id: I06221de3633d1ad30160bfc83d53a3b98f586f39
    Partial-Bug: #1769970
    Signed-off-by: Jorge Niedbalski <email address hidden>

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/queens
Review: https://review.openstack.org/568371

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/568371
Committed: https://git.openstack.org/cgit/openstack/kolla/commit/?id=ae322168f65a3ba204795080f6e936356b9b19cd
Submitter: Zuul
Branch: stable/queens

commit ae322168f65a3ba204795080f6e936356b9b19cd
Author: Jorge Niedbalski <email address hidden>
Date: Tue May 8 15:47:43 2018 -0300

    Create symlink if /e/o-d/customer_local_settings exists

    Create site-packages custom_local_settings symlink if /etc/openstack-dashboard/custom_
    local_settings exists, this will be used as a mechanism to extend the
    current local_settings without a need to change the file and rebuild
    the image

    Change-Id: If4043a5064a6b94bf08bd8363a895da921bc2418
    Partial-Bug: #1769970
    (cherry picked from commit 479daab59b4a1faad3a4ab5b7f6ecc4887ffea3a)
    Signed-off-by: Jorge Niedbalski <email address hidden>

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/550800
Committed: https://git.openstack.org/cgit/openstack/kolla-ansible/commit/?id=d516ad7da2d86ad03374f8244f6738ee65d6f6a4
Submitter: Zuul
Branch: master

commit d516ad7da2d86ad03374f8244f6738ee65d6f6a4
Author: Jorge Niedbalski <email address hidden>
Date: Thu Mar 8 13:06:33 2018 +0100

    horizon: allow to configure by custom_local_settings.j2

    kolla-ansible should provide a mechanism to allow operators to overwrite
    the default (or not exposed through configuration) options for the
    local_settings.

    local_settings.j2 may be good place to configure horizon but requires
    operator to sync it every release.

    custom_local_settings.j2 can be used to overwrite things from
    local_settings.j2 without a need of syncing it first.

    This patch also adds a release note and a documentation section
    under the advanced configuration page.

    Partial-Bug: #1769970
    Depends-On: https://review.openstack.org/#/c/567006/
    Change-Id: I84b54ba737276114e512d4577ac4b9010682bb98