Add centos-8 support

Renaming redhat-7.yml to redhat.yml for centos-8 support.

Depends-On: https://review.opendev.org/742166
Change-Id: I05f91dbcd64c8b3f113a920b32ce603bdd58a0d0

tasks/zun_compute.yml

@@ -60,16 +60,33 @@
   when:
     - "ansible_pkg_mgr == 'apt'"
 
-- name: Add yum repository
-  get_url:
-    url: "{{ item.uri }}"
-    dest: "/etc/yum.repos.d/{{ item.name }}.repo"
-    owner: root
-    group: root
-    mode: 0644
+- name: Add docker repo
+  yum_repository:
+    name: "{{ item.name }}"
+    description: "{{ item.description }}"
+    baseurl: "{{ item.uri }}"
+    gpgkey: "{{ item.gpgkey | default(omit) }}"
+    gpgcheck: yes
+    enabled: yes
+    priority: 25
+  register: add_docker_repos
+  until: add_docker_repos is success
+  retries: 5
+  delay: 2
   with_items: "{{ zun_docker_repo }}"
   when:
-    - ansible_pkg_mgr == 'yum'
+    - ansible_pkg_mgr in ['yum', 'dnf']
+
+- name: Enable module_hotfixes
+  lineinfile:
+    dest: "/etc/yum.repos.d/{{ item.name }}.repo"
+    line: "module_hotfixes=1"
+    regexp: "^module_hotfixes"
+    insertafter: "^enabled"
+  with_items: "{{ zun_docker_repo }}"
+  when:
+    - ansible_os_family | lower == 'redhat'
+    - ansible_distribution_major_version is version('8', '>=')
 
 - name: Install compute distro packages
   package:
@@ -77,7 +94,7 @@
     state: "{{ zun_package_state }}"
     update_cache: "{{ (ansible_pkg_mgr in ['apt', 'zypper']) | ternary('yes', omit) }}"
     cache_valid_time: "{{ (ansible_pkg_mgr == 'apt') | ternary(cache_timeout, omit) }}"
-    enablerepo: "{{ (ansible_pkg_mgr == 'yum') | ternary('extras', omit) }}"
+    enablerepo: "{{ (ansible_pkg_mgr in ['yum', 'dnf']) | ternary('extras', omit) }}"
 
 - name: Generate kuryr config
   config_template:

vars/redhat.yml

@@ -15,7 +15,9 @@
 
 zun_docker_repo:
   - name: "docker-ce"
-    uri: "https://download.docker.com/linux/centos/docker-ce.repo"
+    description: Docker CE Stable
+    uri: "https://download.docker.com/linux/centos/7/$basearch/stable"
+    gpgkey: "https://download.docker.com/linux/centos/gpg"
 
 # Common yum packages
 zun_distro_packages:
@@ -23,7 +25,7 @@ zun_distro_packages:
   - systemd-devel
 
 zun_distro_compute_packages:
-  - docker
+  - "{{ (ansible_distribution_major_version is version('8', '<')) | ternary('docker', 'docker-ce') }}"
   - pciutils
 
 zun_docker_groupname: dockerroot