[redhat] Update variables to be version agnostic

The RedHat-based operating systems such as CentOS have a pretty
stable list of packages, therefore, we don't need to pin it by
version and we can instead move to a much more generic redhat.yml
which will support a bigger range of systems.

This patch also sets up the mode for the /etc/mysql directory
to be 755 for things to work.  We should lock that down eventually
for only the MySQL user.

Change-Id: I2e9ee987a353a28da00cd37cbdb82ec46ccc414c

tasks/galera_install_yum.yml

@@ -66,9 +66,11 @@
     path: "{{ item.path }}"
     state: "{{ item.state }}"
     force: "{{ item.force | default(omit) }}"
+    mode: "{{ item.mode | default(omit) }}"
   with_items:
     - path: "/etc/mysql"
       state: "directory"
+      mode: '0755'
     - path: "/etc/mysql/conf.d"
       state: "directory"
     - src: "/usr/lib64/galera"

vars/redhat-7.yml → vars/redhat.yml

@@ -62,7 +62,7 @@ galera_server_upgrade_packages_remove:
 
 galera_mariadb_service_name: "mariadb"
 
-_galera_repo_url: "http://{{ galera_repo_host }}/MariaDB/mariadb-{{ galera_major_version }}.{{ galera_minor_version }}/yum/centos7-amd64"
+_galera_repo_url: "http://{{ galera_repo_host }}/MariaDB/mariadb-{{ galera_client_major_version }}.{{ galera_client_minor_version }}/yum/{{ ansible_distribution | lower }}{{ ansible_distribution_major_version }}-amd64/"
 _galera_repo:
   name: MariaDB
   description: "MariaDB Repo"