Make octavia service_auth project configurable

(Renamed and adapted from Switch octavia to use service project in
 service_auth on master and stable/ussuri)

Recently a patch [1] was merged to stop adding the octavia user to the
admin project, and remove it on upgrade. However, the octavia
configuration was not updated to use the service project, causing load
balancer creation to fail.

There is also an issue for existing deployments in simply switching to
the service project. While existing load balancers appear to continue to
work, creating new load balancers fails due to the security group
belonging to the admin project. At a minimum, the deployer needs to
create a security group in the service project, and update
'octavia_amp_secgroup_list' to match its ID. Ideally the flavor and
network would also be recreated in the service project, although this
does not seem to impact operation and will result in downtime for
existing Amphorae.

This change adds a new variable, 'octavia_service_auth_project', that
can be used to set the project. The default in Ussuri is 'service',
switching to the new behaviour. For backports of this patch to Train and
earlier branches it should be switched to 'admin' to maintain
compatibility.

In Train and earlier, if a deployer keeps the default
'octavia_service_auth_project' of 'admin', the octavia user will be
assigned the admin role in the admin project, as was done previously.
They may also set 'octavia_service_auth_project' to 'service' to use the
new behaviour, and avoid a breaking change when later upgrading to
Ussuri.

Closes-Bug: #1882643
Related-Bug: #1873176

[1] https://review.opendev.org/720243/

Co-Authored-By: Mark Goddard <mark@stackhpc.com>

Change-Id: I1efd0154ebaee69373ae5bccd391ee9c68d09b30
(cherry picked from commit c2037885e7)

ansible/roles/octavia/defaults/main.yml

@@ -123,6 +123,10 @@ octavia_logging_debug: "{{ openstack_logging_debug }}"
 
 octavia_keystone_user: "octavia"
 
+# Project that Octavia will use to interact with other services.  Note that in
+# Ussuri and later releases this will change to "service".
+octavia_service_auth_project: "admin"
+
 openstack_octavia_auth: "{{ openstack_auth }}"
 
 ####################

ansible/roles/octavia/tasks/register.yml

@@ -7,6 +7,20 @@
     service_ks_register_users: "{{ octavia_ks_users }}"
   tags: always
 
+- name: "Adding admin role to octavia user in {{ octavia_service_auth_project }} project"
+  become: true
+  kolla_toolbox:
+    module_name: "os_user_role"
+    module_args:
+      user: "{{ octavia_keystone_user }}"
+      role: admin
+      project: "{{ octavia_service_auth_project }}"
+      auth: "{{ openstack_octavia_auth }}"
+      endpoint_type: "{{ openstack_interface }}"
+      cacert: "{{ openstack_cacert }}"
+  run_once: True
+  when: octavia_service_auth_project != 'service'
+
 - name: Adding octavia related roles
   become: true
   kolla_toolbox:

ansible/roles/octavia/templates/octavia.conf.j2

@@ -32,7 +32,7 @@ auth_type = password
 username = {{ octavia_keystone_user }}
 password = {{ octavia_keystone_password }}
 user_domain_name = {{ default_user_domain_name }}
-project_name = {{ openstack_auth.project_name }}
+project_name = {{ octavia_service_auth_project }}
 project_domain_name = {{ default_project_domain_name }}
 
 memcache_security_strategy = ENCRYPT

releasenotes/notes/fix-octavia-service-auth-project-849a4e5bd852e9c7.yaml

@@ -0,0 +1,40 @@
+---
+fixes:
+  - |
+    In the previous stable release, the octavia user was no longer given the
+    admin role in the admin project, and a task was added to remove the role
+    during upgrades. However, the octavia configuration was not updated to use
+    the service project, causing load balancer creation to fail. See upgrade
+    notes for details.  `LP#1873176
+    <https://bugs.launchpad.net/kolla-ansible/+bug/1873176>`__
+upgrade:
+  - |
+    In the previous stable release, the octavia user was no longer given the
+    admin role in the admin project, and a task was added to remove the role
+    during upgrades. However, the octavia configuration was not updated to use
+    the service project, causing load balancer creation to fail.
+
+    There is also an issue for existing deployments in simply switching to the
+    service project. While existing load balancers appear to continue to work,
+    creating new load balancers fails due to the security group belonging to
+    the admin project. For this reason, Train and Stein have been reverted to
+    use the admin project by default, while from the Ussuri release the service
+    project will be used by default.
+
+    To provide flexibility, an ``octavia_service_auth_project`` variable has
+    been added. In the Train and Stein releases this is set to ``admin`` by
+    default, and from Ussuri it will be set to ``service`` by default.
+    For users of Train and Stein, ``octavia_service_auth_project`` may be set
+    to ``service`` in order to avoid a breaking change during the Ussuri
+    upgrade.
+
+    To switch an existing deployment from using the ``admin`` project to the
+    ``service`` project, it will at least be necessary to create the required
+    security group in the ``service`` project, and update
+    ``octavia_amp_secgroup_list`` to this group's ID. Ideally the Amphora
+    flavor and network would also be recreated in the ``service`` project,
+    although this does not appear to be necessary for operation, and will
+    impact existing Amphorae.
+
+    See `bug 1873176 <https://bugs.launchpad.net/kolla-ansible/+bug/1873176>`__
+    for details.