server-infra/roles/app-deploy/tasks/django.yml

---
# Deploy one Django app+env as its own docker compose project.
# Called per item with loop_var app_item = { name, env, port }.

- name: "django[{{ app_item.name }}/{{ app_item.env }}] locals"
  ansible.builtin.set_fact:
    _spec: "{{ app_catalog[app_item.name] }}"
    _src: "{{ apps_src_dir }}/{{ app_item.name }}_{{ app_item.env }}"
    _envfile: "{{ apps_env_dir }}/{{ app_item.name }}_{{ app_item.env }}.env"
    _secret_src: "{{ secrets_dir }}/{{ app_item.name }}/{{ app_item.name }}_{{ app_item.env }}.env"
    _project: "{{ app_item.name }}_{{ app_item.env }}"
    _ref: "{{ app_ref | default(app_catalog[app_item.name].default_branch) }}"

- name: "django[{{ _project }}] ensure base dirs"
  ansible.builtin.file:
    path: "{{ item }}"
    state: directory
    owner: "{{ admin_user }}"
    group: "{{ admin_user }}"
    mode: "0750"
  loop:
    - "{{ apps_src_dir }}"
    - "{{ apps_env_dir }}"

- name: "django[{{ _project }}] check local secret exists"
  ansible.builtin.stat:
    path: "{{ _secret_src }}"
  register: _secret_stat
  delegate_to: localhost
  become: false

- name: "django[{{ _project }}] fail when local secret missing"
  ansible.builtin.fail:
    msg: >-
      Missing local secret {{ _secret_src }} on the control node.
      Create it (DATABASE_URL to the shared external Postgres, DJANGO_SECRET_KEY,
      WEB_PORT={{ app_item.port }}, etc.) before deploying. It is never committed
      to git.
  when: not _secret_stat.stat.exists

- name: "django[{{ _project }}] push secret to {{ _envfile }}"
  ansible.builtin.copy:
    src: "{{ _secret_src }}"
    dest: "{{ _envfile }}"
    owner: "{{ admin_user }}"
    group: "{{ admin_user }}"
    mode: "0600"

- name: "django[{{ _project }}] checkout {{ _ref }}"
  ansible.builtin.git:
    repo: "{{ _spec.repo }}"
    dest: "{{ _src }}"
    version: "{{ _ref }}"
    force: true
    accept_hostkey: true
  become: true
  become_user: "{{ admin_user }}"

- name: "django[{{ _project }}] install .env into checkout"
  ansible.builtin.copy:
    src: "{{ _envfile }}"
    dest: "{{ _src }}/.env"
    remote_src: true
    owner: "{{ admin_user }}"
    group: "{{ admin_user }}"
    mode: "0600"

- name: "django[{{ _project }}] build images"
  ansible.builtin.command:
    cmd: "docker compose -f {{ _spec.compose_file }} --env-file .env build"
    chdir: "{{ _src }}"
  environment:
    COMPOSE_PROJECT_NAME: "{{ _project }}"
    WEB_PORT: "{{ app_item.port }}"
  become: true
  become_user: "{{ admin_user }}"
  changed_when: true

- name: "django[{{ _project }}] legacy systemd unit"
  ansible.builtin.set_fact:
    _legacy_systemd: "{{ _spec.legacy_systemd_units[app_item.env] | default('') }}"
  when: _spec.legacy_systemd_units is defined

- name: "django[{{ _project }}] probe legacy systemd unit"
  ansible.builtin.command:
    cmd: systemctl list-unit-files {{ _legacy_systemd }}.service --no-legend
  register: _legacy_systemd_probe
  changed_when: false
  failed_when: false
  become: true
  when: _legacy_systemd | default('') | length > 0

- name: "django[{{ _project }}] stop legacy systemd unit"
  ansible.builtin.systemd:
    name: "{{ _legacy_systemd }}"
    state: stopped
    enabled: false
  become: true
  when:
    - _legacy_systemd | default('') | length > 0
    - _legacy_systemd_probe.stdout | default('') | length > 0

- name: "django[{{ _project }}] start containers"
  ansible.builtin.command:
    cmd: "docker compose -f {{ _spec.compose_file }} --env-file .env up -d --remove-orphans"
    chdir: "{{ _src }}"
  environment:
    COMPOSE_PROJECT_NAME: "{{ _project }}"
    WEB_PORT: "{{ app_item.port }}"
  become: true
  become_user: "{{ admin_user }}"
  changed_when: true