Added support for RHEL 7 & 8

defaults/main.yml

@@ -2,16 +2,94 @@
 # A list of users to be added to the docker group.
 docker_users: []
 
-centos_repo_file: docker-ce.repo
+docker_base_url: "https://download.docker.com/linux"
-centos_repo_full_path: "/etc/yum.repos.d/{{ centos_repo_file }}"
+docker_distro_aliases:
-centos_repo_url: "https://download.docker.com/linux/centos/\
+  CentOS: centos
-                  {{ centos_repo_file }}"
+  # RedHat -> centos is intentional.
+  RedHat: centos
+  Ubuntu: ubuntu
+docker_distro_base_url: "{{ docker_base_url }}/\
+                         {{ docker_distro_aliases[ansible_distribution] }}"
 
-ubuntu_docker_base_url: https://download.docker.com/linux/ubuntu
+################################################################################
-ubuntu_gpg_url: "{{ ubuntu_docker_base_url }}/gpg"
+# RedHat family docker repo.
+################################################################################
+
+redhat_fam_docker_repo_file: docker-ce.repo
+redhat_fam_repo_url: "{{ docker_base_url }}/\
+                      {{ docker_distro_aliases[ansible_distribution] }}/\
+                      {{ redhat_fam_docker_repo_file }}"
+redhat_fam_docker_repo_full_path: "{{ redhat_fam_repo_base_path }}/\
+                                   {{ redhat_fam_docker_repo_file }}"
+
+################################################################################
+# RedHat family extras repo.
+#
+# The extras repo holds some packages that are dependencies of docker.
+################################################################################
+
+redhat_fam_repo_base_path: /etc/yum.repos.d
+
+# RedHat 8 doesn't seem to have an extras repo. Docker also installs fine i RHEL
+# 8 without making any changes to an extras repo.
+redhat_7_extras_repo_file: redhat.repo
+redhat_7_extras_group: rhel-7-server-extras-rpms
+centos_7_extras_repo_file: CentOS-Sources.repo
+centos_8_extras_repo_file: CentOS-Linux-Extras.repo
+centos_7_8_extras_group: extras
+
+redhat_fam_extras_repo_file:
+  CentOS:
+    "7":
+      repo: "{{ redhat_fam_repo_base_path }}/{{ centos_7_extras_repo_file }}"
+      group: "{{ centos_7_8_extras_group }}"
+    "8":
+      repo: "{{ redhat_fam_repo_base_path }}/{{ centos_8_extras_repo_file }}"
+      group: "{{ centos_7_8_extras_group }}"
+  RedHat:
+    "7":
+      repo: "{{ redhat_fam_repo_base_path }}/{{ redhat_7_extras_repo_file }}"
+      group: "{{ redhat_7_extras_group }}"
+
+
+################################################################################
+# Ubuntu 3rd party repo.
+################################################################################
+
+ubuntu_gpg_url: "{{ docker_distro_base_url }}/gpg"
 ubuntu_gpg_fingerprint: 9DC858229FC7DD38854AE2D88D81803C0EBFCD88
 ubuntu_apt_repo: >
   deb [arch=amd64]
-  "{{ ubuntu_docker_base_url }}"
+  "{{ docker_distro_base_url }}"
   "{{ ansible_distribution_release }}"
   stable
+
+################################################################################
+# Thes are the packages that are removed before adding the 3rd party repo.
+################################################################################
+
+centos_remove_old_packages:
+  - docker
+  - docker-client
+  - docker-client-latest
+  - docker-common
+  - docker-latest
+  - docker-latest-logrotate
+  - docker-logrotate
+  - docker-engine
+
+ubuntu_remove_old_packages:
+  - docker
+  - docker-engine
+  - docker.io
+  - containerd
+  - runc
+
+# A map of ansible_distribution -> old packages to remove.
+#
+# We use centos for RedHat because Docker doesn't officially support RHEL for
+# x86_64, however the centos repo works.
+docker_remove_old_packages:
+  CentOS: "{{centos_remove_old_packages}}"
+  RedHat: "{{centos_remove_old_packages}}"
+  Ubuntu: "{{ubuntu_remove_old_packages}}"

meta/main.yml

@@ -16,9 +16,11 @@ galaxy_info:
     - name: Amazon Linux 2
       versions:
         - all
+    - name: EL
+        - 7
+        - 8
     - name: Ubuntu
         - focal  # 20.04
-    # CentOS is apparently not in https://galaxy.ansible.com/api/v1/platforms/
 
   galaxy_tags:
     - containers

tasks/main.yml

@@ -2,27 +2,38 @@
 # This has only been tests on Amazon Linux 2, CentOS 7-8, Ubuntu 20.04, and
 # ArchLinux.
 
+################################################################################
 # Prequisites
 # This step will:
 # 1. Remove any unwanted docker packages, (we want newest package from official
 #    docker repos.
 # 2. Install dependencies.
 # 3. Add official docker repo.
+################################################################################
 
 # Archlinux and Amazon Linux don't have any prequisite steps, they're
 # repositories have up to date docker packages so we don't need to add a 3rd
 # party repo or uninstall unwanted packages.
 
-- include_tasks: prereq_centos.yml
+- include_tasks: prereq_redhat_family.yml
-  when: ansible_distribution == "CentOS"
+  # We need to exclude Amazon because it's technically in the "RedHat" family
+  # but it does not require these prereq steps.
+  when: ansible_os_family == "RedHat" and ansible_distribution != "Amazon"
 
 - include_tasks: prereq_ubuntu.yml
   when: ansible_distribution == "Ubuntu"
 
-# The arch cloud image does not have a package cache.
+################################################################################
+# End prerequisite steps
+################################################################################
+
+# The arch cloud image does not have a package cache, this file will update the
+# cache only if we need to install the docker package (not already installed).
 - include_tasks: update_arch.yml
   when: ansible_distribution == "Archlinux"
 
+# Install the docker packages. The packages and their names depends on the
+# distro,
 - name: Install docker packages after adding 3rd party repo.
   package:
     name:

tasks/prereq_centos.yml

@@ -1,103 +0,0 @@
----
-# This commented out code was an attempt to make sure the CentOS extras repo is
-# enabled.
-# TODO This isn't working. It will create the repo everytime regardless whether
-# or not the repo is already enabled. For now we leave it because this repo is
-# enabled by defaullt on CentOS 7 & 8
-#
-# https://docs.docker.com/engine/install/centos/#os-requirements
-# Look in /etc/yum.repos.d/ for examples of the fields for a repo. This files
-# have variables in their config. To get the values of the variables you can
-# run:
-# `python -c 'import yum; yb = yum.YumBase(); print(yb.conf.yumvar)'`
-# - name: Ensure CentOS extras repo is enbaled for CentOS 7.
-#   yum_repository:
-#     name: extras
-#     description: CentOS-{{ ansible_distribution_major_version }} - Extras
-#     enabled: true
-#     mirrorlist: "http://mirrorlist.centos.org/?\
-#                  release={{ ansible_distribution_major_version }}&\
-#                  arch={{ ansible_architecture }}&\
-#                  repo=extras&infra=genclo"
-#     gpgcheck: true
-#   become: true
-#   when: >
-#       ansible_distribution == "CentOS" and
-#       ansible_distribution_major_version == "7"
-# - name: Ensure CentOS extras repo is enbaled for CentOS 8.
-#   yum_repository:
-#     name: extras
-#     description: >
-#       CentOS Linux {{ ansible_distribution_major_version }} - Extras
-#     enabled: true
-#     mirrorlist: "http://mirrorlist.centos.org/?\
-#                  release={{ ansible_distribution_major_version }}&\
-#                  arch={{ ansible_architecture }}&\
-#                  repo=extras&infra=genclo"
-#     gpgcheck: true
-#   become: true
-#   when: >
-#       ansible_distribution == "CentOS" and
-#       ansible_distribution_major_version == "8"
-
-# TODO Add this step.
-# https://docs.docker.com/engine/install/centos/#os-requirements
-
-################################################################################
-# Uninstall unwanted docker packages.
-################################################################################
-
-# This step combines "Uninstall old versions" for RedHat family distros.
-# https://docs.docker.com/engine/install/centos/#uninstall-old-versions
-# https://docs.docker.com/engine/install/fedora/#uninstall-old-versions
-# https://docs.docker.com/engine/install/rhel/#uninstall-old-versions
-
-# We check if a docker repo has alredy been added to yum. If so, then we want to
-# skip the removing of the old docker packages to make this script more
-# idempotent.
-- name: Check if docker repo has alredy been added.
-  command: yum repolist  # noqa command-instead-of-module
-  changed_when: false
-  register: repolist
-
-- name: Uninstall old versions of docker RedHat like distros..
-  yum:
-    name:
-      - docker
-      - docker-client
-      - docker-client-latest
-      - docker-common
-      - docker-latest
-      - docker-latest-logrotate
-      - docker-logrotate
-      - docker-selinux
-      - docker-engine-selinux
-      - docker-engine
-      - podman
-      - runc
-    state: absent
-  become: true
-  when: "'docker' not in repolist.stdout"
-
-################################################################################
-# Install dependencies
-################################################################################
-
-# https://docs.docker.com/engine/install/centos/#install-using-the-repository
-- name: Install dependencies for yum distros.
-  yum:
-    name:
-      - yum-utils
-    state: present
-  become: true
-
-################################################################################
-# Install docker repo.
-################################################################################
-
-# https://docs.docker.com/engine/install/centos/#install-using-the-repository
-- name: Add docker yum repo for centos.
-  command:
-    cmd: "yum-config-manager --add-repo {{ centos_repo_url }}"
-    creates: "{{ centos_repo_full_path }}"
-  become: true

tasks/prereq_redhat_family.yml

@@ -0,0 +1,63 @@
+---
+# https://docs.docker.com/engine/install/centos/#os-requirements
+- name: Enable the extras repo in RedHat family distros.
+  ini_file:
+    path: "{{ redhat_fam_extras_repo_file[ansible_distribution]\
+              [ansible_distribution_major_version].repo }}"
+    section: "{{ redhat_fam_extras_repo_file[ansible_distribution]\
+                 [ansible_distribution_major_version].group }}"
+    option: enabled
+    value: 1
+    mode: '0644'
+    exclusive: true
+    state: present
+    backup: true
+  become: true
+  when: >
+    ansible_distribution == "CentOS" or
+    ( ansible_distribution == "RedHat" and
+      ansible_distribution_major_version == "7" )
+
+################################################################################
+# Uninstall unwanted docker packages.
+################################################################################
+
+# https://docs.docker.com/engine/install/centos/#uninstall-old-versions
+#
+# We check if a docker repo has alredy been added to yum. If so, then we want to
+# skip the removing of the old docker packages to make this script more
+# idempotent.
+- name: Check if docker repo has already been added.
+  command: yum repolist  # noqa command-instead-of-module
+  changed_when: false
+  register: repolist
+
+- name: Uninstall old versions of docker RedHat like distros.
+  yum:
+    name: "{{ docker_remove_old_packages[ansible_distribution] }}"
+    state: absent
+  become: true
+  when: "'docker' not in repolist.stdout"
+
+################################################################################
+# Install dependencies
+################################################################################
+
+# https://docs.docker.com/engine/install/centos/#install-using-the-repository
+- name: Install dependencies for yum distros.
+  yum:
+    name:
+      - yum-utils
+    state: present
+  become: true
+
+################################################################################
+# Install docker repo.
+################################################################################
+
+# https://docs.docker.com/engine/install/centos/#install-using-the-repository
+- name: Add docker yum repo for centos.
+  command:
+    cmd: "yum-config-manager --add-repo {{ redhat_fam_repo_url }}"
+    creates: "{{ redhat_fam_docker_repo_full_path }}"
+  become: true

tasks/prereq_ubuntu.yml

@@ -6,12 +6,7 @@
 # https://docs.docker.com/engine/install/ubuntu/#uninstall-old-versions
 - name: Remove old docker packages for Debian like distros.
   apt:
-    name:
+    name: "{{ docker_remove_old_packages[ansible_distribution] }}"
-      - docker
-      - docker-engine
-      - docker.io
-      - containerd
-      - runc
     state: absent
   become: true
 

tasks/update_arch.yml

@@ -1,5 +1,5 @@
 ---
-# These tasks will update the pacman repos if Docker is not alredy instflled.
+# These tasks will update the pacman repos if Docker is not already installed.
 #
 # We only want to update the chache if needed, otherwise this will break
 # idempotentcy.