如何在Ansible中通过循环动态生成docker-compose配置文件

步骤1：完善服务配置YML #

将每个服务的独有配置（端口、额外主机、环境变量等）补充到你的服务定义YML中，后续直接从该文件读取所有配置，无需在模板硬编码：

services:
  - service: "front"
    image: "acalls-caselog-web-app"
    version: "latest"
    ports:
      - "81:81"
    extra_hosts:
      - "backend:172.32.3.46"
    environment:
      profile: preproduction
  - service: "back"
    image: "acalls-caselog-web-service"
    version: "latest"
    ports:
      - "20101:20101"
    environment:
      profile: preproduction
  - service: "vb"
    image: "acalls-caselog-vb-service"
    version: "latest"
    ports:
      - "20102:20102"
    environment:
      profile: preproduction
  - service: "salesforce"
    image: "acalls-caselog-salesforce-app-service"
    version: "latest"
    ports:
      - "20103:20103"
    environment:
      profile: preproduction
  - service: "tts"
    image: "ydilo-tts-service"
    version: "latest"
    ports:
      - "20104:20104"
    environment:
      profile: preproduction
  - service: "ai_classifier"
    image: "acalls-caselog-ai-classifier-service"
    version: "latest"
    ports:
      - "20105:20105"
    environment:
      profile: preproduction

注意：请将原配置中的ai classifier改为ai_classifier，Docker Compose服务名称不支持空格。

步骤2：修改Ansible任务文件 #

在原有任务前增加加载服务配置的步骤，假设你的服务配置YML文件路径为vars/service_list.yml：

---
- name: 加载服务配置列表
  include_vars:
    file: vars/service_list.yml

- name: 停止现有容器
  ignore_errors: yes
  become: True
  shell:
    cmd: "docker-compose down"
    chdir: /你的部署目录路径

- name: 生成docker-compose配置文件
  template:
    src: docker-compose-acalls.yml.j2
    dest: /你的部署目录路径/docker-compose.yml
    mode: 0700

- name: 启动容器
  become: True
  shell:
    cmd: "nohup docker-compose -f docker-compose.yml up -d"
    chdir: /你的部署目录路径

步骤3：编写Jinja2模板文件（docker-compose-acalls.yml.j2） #

使用Jinja2循环语法遍历服务列表，动态生成服务配置，完全不需要硬编码数组下标：

version: "3.3"
services:
{% for svc in services %}
  {{ svc.service }}:
    image: 你的镜像仓库地址/{{ svc.image }}:{{ svc.version }}
    {% if svc.ports is defined %}
    ports:
      {% for port in svc.ports %}
      - "{{ port }}"
      {% endfor %}
    {% endif %}
    {% if svc.extra_hosts is defined %}
    extra_hosts:
      {% for host in svc.extra_hosts %}
      - "{{ host }}"
      {% endfor %}
    {% endif %}
    {% if svc.environment is defined %}
    environment:
      {% for key, value in svc.environment.items() %}
      {{ key }}: {{ value }}
      {% endfor %}
    {% endif %}
{% endfor %}

模板里加了字段存在性判断，部分服务没有的配置（比如extra_hosts）不会生成对应字段，避免语法错误。

内容的提问来源于stack exchange，提问作者Alejandro Sánchez