Replace systemd unit overrides with role

Instead of placing bunch of templates, we can use our systemd_role
that is capable of placing just overrides file, that will have same
functionality but also provide ability to easily add required data into
systemd overrides.

Change-Id: I7b3b0f4da047f82a49266ef57fba2fbaa24cebdc

defaults/main.yml

@@ -148,6 +148,7 @@ galera_my_cnf_overrides: {}
 galera_cluster_cnf_overrides: {}
 galera_debian_cnf_overrides: {}
 galera_encryption_overrides: {}
+galera_init_overrides: {}
 
 # Set the max connections value for galera. Set this value to override the
 # computed value which is (100 x vCPUs) with a cap of 1600. If computed, the

releasenotes/notes/mariadb_systemd_overrides-6536a0ee5e612698.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    Added variable ``galera_init_overrides`` that can be leveraged to override
+    default set of systemd unit file for mariadb.
+    This also brings requirement of `systemd_service <https://opendev.org/openstack/ansible-role-systemd_service>`_
+    role.

tasks/galera_server_post_install.yml

@@ -13,34 +13,32 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Create mariadb systemd service config dir
+# TODO(noonedeadpunk): Remove task and called handler after X release
+- name: Remove old systemd overrides
   file:
-    path: "/etc/systemd/system/{{ galera_mariadb_service_name }}.service.d"
-    state: "directory"
-    group: "root"
-    owner: "root"
-    mode: "0755"
-
-- name: Apply systemd options
-  template:
-    src: "{{ item.src }}"
-    dest: "/etc/systemd/system/{{ galera_mariadb_service_name }}.service.d/{{ item.dest }}"
-    mode: "0644"
+    path: "/etc/systemd/system/{{ galera_mariadb_service_name }}.service.d/{{ item }}"
+    state: absent
   with_items:
-    - { src: "systemd.environment.conf.j2", dest: "environment.conf" }
-    - { src: "systemd.limits.conf.j2", dest: "limits.conf" }
-    - { src: "systemd.restart.conf.j2", dest: "restart.conf" }
-    - { src: "systemd.slice.conf.j2", dest: "slice.conf" }
-    - { src: "systemd.timeout.conf.j2", dest: "timeout.conf" }
-    - { src: "systemd.without-privatedevices.conf.j2", dest: "without-privatedevices.conf" }
-  notify:
-    - Manage LB
-    - Reload the systemd daemon
-    - Restart all mysql
+    - environment.conf
+    - limits.conf
+    - restart.conf
+    - slice.conf
+    - timeout.conf
+    - without-privatedevices.conf
+  when: galera_upgrade | bool
+  notify: Reload the systemd daemon
 
-- name: Reload systemd service files
-  systemd:
-    daemon_reload: yes
+- name: Run the systemd service role
+  import_role:
+    name: systemd_service
+  vars:
+    systemd_tempd_prefix: openstack
+    systemd_services:
+      - service_name: "{{ galera_mariadb_service_name }}"
+        systemd_overrides_only: True
+        systemd_overrides: "{{ galera_init_defaults | combine(galera_init_overrides) }}"
+  tags:
+    - galera-service
 
 # NOTE(cloudnull): The secure task is not needed on Debian based systems
 #                  as all of these tasks will be run on Package install
@@ -134,7 +132,6 @@
   notify:
     - Manage LB
     - Restart all mysql
-    - Reload the systemd daemon
 
 - name: Link mysql and mariadb config files
   file:

templates/systemd.environment.conf.j2

@@ -1,8 +0,0 @@
-# {{ ansible_managed }}
-
-[Service]
-# https://jira.mariadb.org/browse/MDEV-14256
-Environment="WSREP_SST_OPT_PORT=4444"
-
-# Configure Linux OOM killer to prioritize other targets than mariadb
-OOMScoreAdjust=-1000

templates/systemd.limits.conf.j2

@@ -1,5 +0,0 @@
-# {{ ansible_managed }}
-
-[Service]
-LimitNOFILE={{ galera_file_limits }}
-

templates/systemd.restart.conf.j2

@@ -1,9 +0,0 @@
-# {{ ansible_managed }}
-
-[Service]
-# Define the condition under which the service will be restarted
-# on-abort is the most conservative one since that should capture unexpected
-# failures but also exclude failures due to bad configurations. This is
-# currently the upstream option as well
-Restart=on-abort
-RestartSec=5s

templates/systemd.slice.conf.j2

@@ -1,11 +0,0 @@
-# {{ ansible_managed }}
-
-[Service]
-# This creates a specific slice to operate from. The accounting options give us
-# the ability to see resource usage through the `systemd-cgtop` command and
-# further isolate this service from the host machine.
-Slice=galera.slice
-CPUAccounting=true
-BlockIOAccounting=true
-MemoryAccounting=false
-TasksAccounting=true

templates/systemd.timeout.conf.j2

@@ -1,6 +0,0 @@
-# {{ ansible_managed }}
-
-[Service]
-# How long to wait for successful mysql startup
-# Startup can take a while if it requires a galera state transfer.
-TimeoutStartSec={{ galera_startup_timeout }}

templates/systemd.without-privatedevices.conf.j2

@@ -1,4 +0,0 @@
-# {{ ansible_managed }}
-
-[Service]
-PrivateDevices={{ galera_disable_privatedevices | bool | ternary('false', 'true') }}

templates/upstart.limits.conf.j2

@@ -1,4 +0,0 @@
-# {{ ansible_managed }}
-
-# OpenFile limits
-*    -    nofile    {{ galera_file_limits }}

vars/main.yml

@@ -0,0 +1,29 @@
+---
+# Copyright 2021, City Network International AB
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+galera_init_defaults:
+  Service:
+    LimitNOFILE: "{{ galera_file_limits }}"
+    Restart: on-abort
+    RestartSec: 5s
+    Slice: galera.slice
+    CPUAccounting: true
+    BlockIOAccounting: true
+    MemoryAccounting: false
+    TasksAccounting: true
+    TimeoutStartSec: "{{ galera_startup_timeout }}"
+    PrivateDevices: "{{ galera_disable_privatedevices | bool | ternary('false', 'true') }}"
+    OOMScoreAdjust: "-1000"