kubespray/roles/docker/tasks/main.yml

---
- name: gather os specific variables
  include_vars: "{{ item }}"
  with_first_found:
    - files:
      - "{{ ansible_distribution|lower }}-{{ ansible_distribution_version|lower|replace('/', '_') }}.yml"
      - "{{ ansible_distribution|lower }}-{{ ansible_distribution_release }}.yml"
      - "{{ ansible_distribution|lower }}-{{ ansible_distribution_major_version|lower|replace('/', '_') }}.yml"
      - "{{ ansible_distribution|lower }}.yml"
      - "{{ ansible_os_family|lower }}.yml"
      - defaults.yml
      paths:
      - ../vars
      skip: true

- name: check for minimum kernel version
  fail:
    msg: >
          docker requires a minimum kernel version of
          {{ docker_kernel_min_version }} on
          {{ ansible_distribution }}-{{ ansible_distribution_version }}
  when: (ansible_os_family != "CoreOS") and (ansible_kernel|version_compare(docker_kernel_min_version, "<"))

- name: ensure docker repository public key is installed
  action: "{{ docker_repo_key_info.pkg_key }}"
  args:
    id: "{{item}}"
    keyserver: "{{docker_repo_key_info.keyserver}}"
    state: present
  with_items: "{{ docker_repo_key_info.repo_keys }}"
  when: ansible_os_family != "CoreOS"

- name: ensure docker repository is enabled
  action: "{{ docker_repo_info.pkg_repo }}"
  args:
    repo: "{{item}}"
    state: present
  with_items: "{{ docker_repo_info.repos }}"
  when: (ansible_os_family != "CoreOS") and (docker_repo_info.repos|length > 0)

- name: Configure docker repository on RedHat/CentOS
  copy:
    src: "rh_docker.repo"
    dest: "/etc/yum.repos.d/docker.repo"
  when: ansible_distribution in ["CentOS","RedHat"] and
        ansible_distribution_major_version >= 7

- name: ensure docker packages are installed
  action: "{{ docker_package_info.pkg_mgr }}"
  args:
    pkg: "{{item.name}}"
    force: "{{item.force|default(omit)}}"
    state: present
  with_items: "{{ docker_package_info.pkgs }}"
  when: (ansible_os_family != "CoreOS") and (docker_package_info.pkgs|length > 0)

- name: allow for proxies on systems using systemd
  include: systemd-proxies.yml
  when: ansible_service_mgr == "systemd" and
        (http_proxy is defined or https_proxy is defined or no_proxy is defined)

- name: Write docker.service systemd file
  template:
    src: systemd-docker.service.j2
    dest: /etc/systemd/system/docker.service
  register: docker_service_file
  notify: restart docker
  when: ansible_service_mgr == "systemd" and ansible_os_family != "CoreOS"

- meta: flush_handlers

- name: ensure docker service is started and enabled
  service:
    name: "{{ item }}"
    enabled: yes
    state: started
  with_items:
    - docker