Switch galera_install_dnf back to being a symlink

In I239a472c1d76f1cc00666280a93b73ecd84ba3d9 the galera_install_dnf
task file was mistakenly changed from a symlink to a copy of the
galera_install_yum file. Since then its contents have drifted from
the yum install process, but it's supposed to be exactly the same..

This patch switches it back to being a symlink to reduce the cost
of maintenance.

Change-Id: If7c40e7459e06526e883dc5a36b4fd31177598f1

tasks/galera_install_dnf.yml

@@ -1,109 +0,0 @@
----
-# Copyright 2016, Rackspace US, Inc.
-#
-# 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.
-
-- name: Update the local file system CRUD
-  file:
-    src: "{{ item.src|default(omit) }}"
-    path: "{{ item.path }}"
-    state: "{{ item.state }}"
-    force: "{{ item.force|default(omit) }}"
-  with_items:
-    - { path: "/etc/mysql", state: "directory" }
-    - { path: "/etc/mysql/conf.d", state: "directory" }
-    - { src: "/usr/lib64/galera", path: "/usr/lib/galera", state: "link", force: true }
-    - { src: "/etc/mysql/conf.d", path: "/etc/my.cnf.d", state: "link", force: true }
-    - { src: "/etc/mysql/my.cnf", path: "/etc/my.cnf", state: "link", force: true }
-
-- name: If a keyfile is provided, copy the gpg keyfile to the key location
-  copy:
-    src: "{{ item.keyfile }}"
-    dest: "{{ item.key }}"
-    mode: '0644'
-  with_items: "{{ galera_gpg_keys | selectattr('keyfile','defined') | list }}"
-
-- name: Install gpg keys
-  rpm_key:
-    key: "{{ key.key }}"
-    validate_certs: "{{ key.validate_certs | default(omit) }}"
-    state: "{{ key.state | default('present') }}"
-  with_items: "{{ galera_gpg_keys }}"
-  loop_control:
-    loop_var: key
-  register: _add_yum_keys
-  until: _add_yum_keys is success
-  retries: 5
-  delay: 2
-
-- name: Add galera repo
-  yum_repository:
-    name: "{{ galera_repo.name }}"
-    description: "{{ galera_repo.description }}"
-    baseurl: "{{ galera_repo.baseurl }}"
-    gpgkey: "{{ galera_repo.gpgkey | default(omit) }}"
-    gpgcheck: yes
-    enabled: yes
-  register: add_repos
-  until: add_repos is success
-  retries: 5
-  delay: 2
-
-# When changing the repo URL, the metadata does
-# not reliably update, resulting in the right
-# URL being used, but the wrong package list.
-# This is why we force the metadata to be
-# cleaned out whenever the repo config changes.
-- name: Force the expiry of the repo metadata
-  command: "{{ ansible_pkg_mgr }} clean metadata"
-  args:
-    warn: no
-  when: add_repos is changed
-  tags:
-    - skip_ansible_lint
-
-- name: Install percona repo
-  yum_repository:
-    name: 'percona-release-$basearch'
-    description: 'Percona-Release YUM repository - $basearch'
-    baseurl: "{{ galera_percona_xtrabackup_repo.repo }}"
-    enabled: true
-    gpgcheck: true
-    state: "{{ galera_percona_xtrabackup_repo.state }}"
-  register: install_packages
-  until: install_packages is success
-  retries: 5
-  delay: 2
-
-# NOTE(mhayden): MariaDB/percona repositories are prioritized at 99 by default
-# and that allows yum to install galera from the RDO repos, which is not good.
-# This task ensures that the following task will choose MariaDB/percona repos
-# as the highest priority.
-- name: Ensure MariaDB/percona repositories take highest priority
-  command: |
-    yum-config-manager
-      --enable {{ item }}
-      --setopt="{{ item }}.priority=25"
-  with_items:
-    - MariaDB
-    - percona-release-noarch
-    - percona-release-x86_64
-
-- name: Install galera_server role remote packages
-  package:
-    name: "{{ galera_packages_list }}"
-    state: "{{ galera_server_package_state }}"
-  register: install_remote_packages
-  until: install_remote_packages is success
-  retries: 5
-  delay: 2

tasks/galera_install_dnf.yml

@@ -0,0 +1 @@
+galera_install_yum.yml