Remove references to unsupported operating systems

All references to Gentoo, SUSE, Debian stretch and Centos-7  are removed.
Conditional tasks, ternary operators and variables are simplified where possible
OS specific variables files are generalised where possible

Change-Id: Ic1b8b532adec2c46373d3a0a3cea8387bff7817a

meta/main.yml

@@ -22,16 +22,14 @@ galaxy_info:
   platforms:
     - name: Debian
       versions:
-        - stretch
+        - buster
     - name: Ubuntu
       versions:
-        - xenial
+        - bionic
+        - focal
     - name: EL
       versions:
-        - 7
-    - name: opensuse
-      versions:
-        - 15
+        - 8
   galaxy_tags:
     - cloud
     - rabbitmq

tasks/install_zypper.yml

@@ -1,40 +0,0 @@
----
-# Copyright 2017, SUSE LINUX GmbH.
-#
-# 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: Fail if installation method is not 'external_repo'
-  fail:
-    msg: "The only supported rabbitmq_install_method for openSUSE is 'external_repo'."
-  when: rabbitmq_install_method != 'external_repo'
-
-- name: Configure repositories
-  zypper_repository:
-    name: "{{ item.name }}"
-    description: "{{ item.description }}"
-    repo: "{{ item.baseurl }}"
-    disable_gpg_check: "{{ item.gpgcheck | default('yes') }}"
-  with_items:
-    - "{{ rabbitmq_erlang_repo }}"
-    - "{{ rabbitmq_repo }}"
-  tags:
-    - rabbitmq-repos
-
-- name: Install RabbitMQ packages
-  zypper:
-    name: "{{ rabbitmq_distro_packages }}"
-    state: "{{ rabbitmq_package_state }}"
-  register: install_rabbitmq
-  tags:
-    - rabbitmq-package-rpm
-    - rabbitmq-zypper-packages

tasks/rabbitmq_install.yml

@@ -18,7 +18,7 @@
 - include_tasks: "install_{{ ansible_facts['pkg_mgr'] }}.yml"
   tags:
     - rabbitmq-apt-packages
-    - rabbitmq-yum-packages
+    - rabbitmq-dnf-packages
     - rabbitmq_server-install
 
 - name: Reload the systemd daemon
@@ -28,8 +28,7 @@
     - install_rabbitmq is changed
   tags:
     - rabbitmq-apt-packages
-    - rabbitmq-yum-packages
-    - rabbimtq-zypper-packages
+    - rabbitmq-dnf-packages
     - rabbitmq_server-install
 
 - name: Ensure there are no policy-rc files

tasks/rabbitmq_upgrade_check.yml

@@ -41,11 +41,10 @@
   register: installed_rabbitmq_rpm
   when:
     - not rabbitmq_upgrade | bool
-    - ansible_facts['pkg_mgr'] in ['yum', 'dnf', 'zypper']
+    - ansible_facts['pkg_mgr'] == 'dnf'
   tags:
     - rabbitmq-package-rpm
-    - rabbitmq-yum-packages
-    - rabbitmq-zypper-packages
+    - rabbitmq-dnf-packages
     - skip_ansible_lint
 
 - name: Register a fact for the installed RabbitMQ version