sonicdocker.yml

##
## Encapsulate docker module with private docker registry, manage the container service
## by systemd on host, so it has full featured depdency control and restart policy
##
## The encapsulated module - sonicdocker
## docker_state: emulate the behavior of docker module
##   ref: http://docs.ansible.com/ansible/docker_module.html
##
## +-------------+------+--------------+----------+---------------------+----------------+-------------+
## | sonicdocker | pull | stop service |  docker  |    post service     | enable service | clean image |
## +-------------+------+--------------+----------+---------------------+----------------+-------------+
## | present     |      |              | present  |                     | y              |             |
## | started     |      |              | present  | started             | y              |             |
## | reloaded    | y    | pulled?      | reloaded | restarted if pulled | y              | if pulled   |
## |             |      |              |          | started if not      |                |             |
## | restarted   |      |              | present  | restarted           | y              |             |
## | stopped     |      | y            | stopped  | stopped             | n              |             |
## | killed      |      | y            | killed   |                     | n              |             |
## | absent      |      | y            | absent   |                     | n              | y           |
## +-------------+------+--------------+----------+---------------------+----------------+-------------+
##

## Set default values for the module variables, emulating local variable definition
## Note: must be consistent with tail part
- name: "{{docker_container}} - Set docker variable - docker_net"
  set_fact:
    docker_net: host
  when: docker_net is undefined
- name: "{{docker_container}} - Set docker variable - docker_state"
  set_fact:
    docker_state: reloaded
  when: docker_state is undefined
- name: "{{docker_container}} - Set docker variable - docker_volumes"
  set_fact:
    docker_volumes: []
  when: docker_volumes is undefined
- name: "{{docker_container}} - Set docker variable - docker_volumes_from"
  set_fact:
    docker_volumes_from: []
  when: docker_volumes_from is undefined
- name: "{{docker_container}} - Set docker variable - docker_privileged"
  set_fact:
    docker_privileged: no
  when: docker_privileged is undefined
- name: "{{docker_container}} - Set docker variable - docker_log_driver"
  set_fact:
    docker_log_driver: json-file
  when: docker_log_driver is undefined
- name: "{{docker_container}} - Set docker variable - docker_env"
  set_fact:
    docker_env: {}
  when: docker_env is undefined
- name: "{{docker_container}} - Set docker variable - docker_tty"
  set_fact:
    docker_tty: yes
  when: docker_tty is undefined
- name: "{{docker_container}} - Set docker variable - docker_log_opt"
  set_fact:
    docker_log_opt: {}
  when: docker_log_driver != "syslog"
- name: "{{docker_container}} - Set docker variable - docker_log_opt"
  set_fact:
    docker_log_opt:
      ## TRICK! TRICK! TRICK!
      ## in ansible 2.0.0.2, reference set_fact varialbe will introduce recursive templating
      ## so double escape by {{'...'}} and {%raw%}...{%endraw%}
      tag: "{{'{%raw%}{{.ID}}({{.Name}}{%endraw%}'}})"
  when: docker_log_driver == "syslog"

## Local variables
- name: "{{docker_container}} - Set docker variable - sonicdocker_container_state"
  set_fact:
    sonicdocker_container_state: "{{docker_state}}"
- name: "{{docker_container}} - Set docker variable - sonicdocker_container_state"
  set_fact:
    sonicdocker_container_state: present
  when: docker_state in ['present', 'started', 'restarted']

## Copy systemd config files for docker container
- name: "{{docker_container}} - Copy systemd config files for docker container"
  become: true
  template:
    src="etc/systemd/system/{{docker_container}}.j2"
    dest="/etc/systemd/system/{{docker_container}}.service"
    owner=root
    group=root
    mode=0644
  register: configfile_result
  when: "docker_state not in ['absent']"

- name: "{{docker_container}} - Reload systemd"
  command: systemctl daemon-reload
  become: yes
  when: configfile_result.changed

- block:
  ## Clean up images before pulling
  - name: "{{docker_container}} - Clean up images before pulling"
    include_tasks: sonicdocker_clean.yml

  ## Pull docker image from registry
  - name: "{{docker_container}} - Pull docker image from registry"
    shell: docker pull {{docker_registry_host}}/{{docker_image}}
    register: pull_result
    changed_when: "'Status: Downloaded newer image' in pull_result.stdout"
  when: docker_state == 'reloaded'

## Stop container service after pulled
- name: "{{docker_container}} - Stop container service after pulled"
  become: true
  service: name="{{docker_container}}"
           state=stopped
  when: "(docker_state == 'reloaded' and 'Status: Downloaded newer image' in pull_result.stdout)      \
        or docker_state in ['stopped', 'killed']"

## Clean up systemd config files for docker container
- name: "{{docker_container}} - Delete systemd config file for docker container"
  become: true
  file:
    path="/etc/systemd/system/{{docker_container}}.service"
    state=absent
  when: "docker_state in ['absent']"
  register: configfile_remove

- name: "{{docker_container}} - Reload systemd"
  command: systemctl daemon-reload
  become: yes
  when: configfile_remove.changed

- name: "{{docker_container}} - Control docker container"
  docker:
    name: "{{docker_container}}"
    image: "{{docker_registry_host}}/{{docker_image}}"
    state: "{{sonicdocker_container_state}}"
    ## Already pulled by upper task
    pull: missing
    detach: yes
    net: "{{docker_net}}"
    tty: "{{docker_tty}}"
    stdin_open: yes
    registry: "https://{{docker_registry_host}}"
    email: "@"
    volumes: "{{docker_volumes}}"
    volumes_from: "{{docker_volumes_from}}"
    privileged: "{{docker_privileged}}"
    env: "{{docker_env}}"
    log_driver: "{{docker_log_driver}}"
    log_opt: "{{docker_log_opt}}"

## Container service operation
- name: "{{docker_container}} - Post docker - restart container service"
  become: true
  service: name="{{docker_container}}"
           state=restarted
  when: "docker_state == 'restarted' or      \
        docker_state == 'reloaded' and 'Status: Downloaded newer image' in pull_result.stdout"

- name: "{{docker_container}} - Post docker - start container service"
  become: true
  service: name="{{docker_container}}"
           state=started
  when: "docker_state == 'started' or docker_state == 'reloaded'"

- name: "{{docker_container}} - Post docker - stop and disable container service"
  become: true
  service: name="{{docker_container}}"
           state=stopped
           enabled=no
  when: docker_state == 'stopped'

- name: "{{docker_container}} - Post docker - enable container service"
  become: true
  service: name="{{docker_container}}"
           enabled={{docker_state in ['present', 'started', 'reloaded', 'restarted']}}

## Clean up images after pulled and running
- name: "{{docker_container}} - Clean up images after pulled and running"
  include_tasks: sonicdocker_clean.yml
  when: "(docker_state == 'reloaded' and 'Status: Downloaded newer image' in pull_result.stdout) or  \
        docker_state == 'absent'"

## Reset the module variables to default values to prevent global side-effect
## Note: must be consistent with header part
- name: "{{docker_container}} - Clean up sonicdocker variables"
  set_fact:
    docker_image: ''
    docker_net: host
    docker_state: reloaded
    docker_volumes: []
    docker_volumes_from: []
    docker_privileged: no
    docker_log_driver: json-file
    docker_env: {}
    docker_tty: yes