Remove Nova legacy upgrade

The rolling upgrade has been the default since Stein. The legacy
upgrade has been removed because it doesn't follow the upgrade
guide [1].

[1] https://docs.openstack.org/nova/latest/user/upgrade.html

Change-Id: I2aa879699cb4e9955bf5c38053eada5a53fb6211

ansible/roles/nova/defaults/main.yml

@@ -359,7 +359,6 @@ nova_logging_debug: "{{ openstack_logging_debug }}"
 openstack_nova_auth: "{{ openstack_auth }}"
 
 nova_compute_host_rp_filter_mode: 0
-nova_enable_rolling_upgrade: "yes"
 nova_safety_upgrade: "no"
 
 nova_libvirt_port: "{{'16514' if libvirt_tls | bool  else '16509'}}"

ansible/roles/nova/tasks/bootstrap_service.yml

@@ -2,18 +2,14 @@
 - name: Running Nova bootstrap container
   vars:
     nova_api: "{{ nova_services['nova-api'] }}"
-    bootstrap_environment:
-      KOLLA_BOOTSTRAP:
-      KOLLA_CONFIG_STRATEGY: "{{ config_strategy }}"
-    upgrade_environment:
-      KOLLA_UPGRADE:
-      KOLLA_CONFIG_STRATEGY: "{{ config_strategy }}"
   become: true
   kolla_docker:
     action: "start_container"
     common_options: "{{ docker_common_options }}"
     detach: False
-    environment: "{{ upgrade_environment if nova_enable_rolling_upgrade|bool else bootstrap_environment }}"
+    environment:
+      KOLLA_UPGRADE:
+      KOLLA_CONFIG_STRATEGY: "{{ config_strategy }}"
     image: "{{ nova_api.image }}"
     labels:
       BOOTSTRAP:

ansible/roles/nova/tasks/legacy_upgrade.yml

@@ -1,28 +0,0 @@
----
-- include_tasks: config.yml
-
-- include_tasks: bootstrap_service.yml
-
-- name: Checking if conductor container needs upgrading
-  become: true
-  kolla_docker:
-    action: "compare_image"
-    common_options: "{{ docker_common_options }}"
-    name: "nova_conductor"
-    image: "{{ nova_conductor_image_full }}"
-  when: inventory_hostname in groups['nova-conductor']
-  register: conductor_differs
-
-# Short downtime here, but from user perspective his call will just timeout or execute later
-- name: Stopping all nova_conductor containers
-  become: true
-  kolla_docker:
-    action: "stop_container"
-    common_options: "{{ docker_common_options }}"
-    name: "nova_conductor"
-  when:
-    - inventory_hostname in groups['nova-conductor']
-    - conductor_differs['result']
-
-- name: Flush handlers
-  meta: flush_handlers

ansible/roles/nova/tasks/precheck.yml

@@ -129,3 +129,11 @@
     - nova_compute_virt_type in ['kvm', 'qemu']
     - container_facts['nova_libvirt'] is not defined
     - inventory_hostname in groups[nova_libvirt.group]
+
+# TODO(mgoddard): Remove this task in the Ussuri cycle.
+- name: Check that legacy upgrade is not enabled
+  fail:
+    msg: >
+      Legacy upgrade support has been removed. 'nova_enable_rolling_upgrade'
+      should no longer be set.
+  when: not nova_enable_rolling_upgrade | default(true) | bool

ansible/roles/nova/tasks/upgrade.yml

@@ -15,11 +15,7 @@
     first_nova_api_host: "{{ groups['nova-api'][0] }}"
   when: hostvars[first_nova_api_host]['nova_upgrade_check_stdout']['rc'] not in [0, 1]
 
-- include_tasks: legacy_upgrade.yml
-  when: not nova_enable_rolling_upgrade | bool
-
 - include_tasks: rolling_upgrade.yml
-  when: nova_enable_rolling_upgrade | bool
 
 # NOTE(jeffrey4l): Remove this task in U cycle.
 - name: Remove nova-consoleauth container

releasenotes/notes/remove-nova-legacy-upgrade-2211024fdadbd70d.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - The legacy upgrade method for Nova has been removed in favour of the
+    rolling upgrade which has been the default since Stein.
+    ``nova_enable_rolling_upgrade`` should no longer be set.