Add EL8 support for ara_api and ara_frontend_nginx roles

This adds support for deploying the ARA API server with an optional
nginx frontend on EL8.

It also sets up integration test jobs to make sure we test it.

Change-Id: I7ce026667ea85d8c59e4910572a34d29f78a8dca

roles/ara_api/README.rst

@@ -7,7 +7,7 @@ This Ansible role provides a framework for installing one or many instances of
 `ARA Records Ansible <https://github.com/ansible-community/ara>`_ in a variety of
 opinionated deployment topologies.
 
-It is currently tested and supported against Ubuntu 18.04 and Fedora 29.
+It is currently tested and supported against Ubuntu 18.04, Fedora 30 and CentOS 8.
 
 Role Variables
 --------------

roles/ara_api/tasks/pre-requirements.yaml

@@ -16,6 +16,18 @@
 #  You should have received a copy of the GNU General Public License
 #  along with ARA Records Ansible. If not, see <http://www.gnu.org/licenses/>.
 
+# EL8 doesn't install a python3 interpreter by default.
+# System packages rely on /usr/libexec/platform-python and Ansible will use it
+# but we want to use the non-system one. Install it if it's missing.
+- name: Ensure python3 is installed for EL8
+  package:
+    name: python3
+    state: present
+  become: yes
+  when:
+    - ansible_distribution | lower in ["redhat", "centos"]
+    - ansible_distribution_major_version == "8"
+
 # The ansible_python_version fact might end up retrieving the version of
 # python2 so we need to explicitely get the version of python 3 available.
 - name: Validate availability of Python 3.5

roles/ara_api/vars/CentOS.yaml

@@ -0,0 +1,38 @@
+---
+#  Copyright (c) 2019 Red Hat, Inc.
+#
+#  This file is part of ARA Records Ansible.
+#
+#  ARA Records Ansible is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  ARA Records Ansible is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with ARA Records Ansible. If not, see <http://www.gnu.org/licenses/>.
+
+# ARA has not been packaged for CentOS or RHEL yet
+ara_distribution_packages: []
+
+ara_api_required_packages:
+  - git
+  - python3
+  - policycoreutils-python-utils
+
+ara_api_postgresql_packages:
+  - postgresql
+  - postgresql-devel
+  - python3-devel
+  - gcc
+
+ara_api_mysql_packages:
+  - mariadb
+  - mariadb-connector-c-devel
+  - redhat-rpm-config
+  - python3-devel
+  - gcc

roles/ara_api/vars/RedHat.yaml

@@ -0,0 +1 @@
+CentOS.yaml

roles/ara_frontend_nginx/vars/CentOS.yaml

@@ -0,0 +1,21 @@
+---
+#  Copyright (c) 2019 Red Hat, Inc.
+#
+#  This file is part of ARA Records Ansible.
+#
+#  ARA Records Ansible is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  ARA Records Ansible is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with ARA Records Ansible. If not, see <http://www.gnu.org/licenses/>.
+
+ara_nginx_user: nginx
+ara_nginx_group: nginx
+ara_nginx_config_path: /etc/nginx/conf.d

roles/ara_frontend_nginx/vars/RedHat.yaml

@@ -0,0 +1 @@
+CentOS.yaml