基于Jinja2模板与变量文件批量生成配置文件的问题排查

我尝试用Jinja2模板文件（server.properties）结合变量文件（common.yml）批量生成多个配置文件，目前文件能正常创建，但只有第一个变量生效，其余变量未在模板中正确渲染。需要生成server1.properties和server2.properties两个文件，每个文件对应节点的配置信息，例如server1.properties的期望输出如下：

node.id= 1
controller.quorum.voters= 1@web.example.com:8080,2@web.example.com:8081,3@web.example.com:8082
############################# Socket Server Settings #############################
listeners= SASL_SSL://web.example.com:18080,CONTROLLER://web.example.com:8080
advertised.listeners= SASL_SSL://web.example.com:18080
############################# Log Basics #############################
log.dirs= /tmp/server1/kraft-combined-logs

Main.yml #

---
- name: Create server properties files
  hosts: localhost
  become: yes
  become_user: root
  gather_facts: true
  vars:
    t_file: server.properties
    t_dir: /path/to/save/newfiles
  tasks:
    - name: Include vars file
      include_vars:
        file: common.yml
        name: common

    - name: Creating template file - server.properties.j2
      template:
        src: "{{ t_file }}"
        dest: 'server.properties.j2'

common.yml #

---
server:
  - server_no: 1
  - server_no: 2
node_id:
  - node_id: 1
  - node_id: 2
cqvoters:
  - cq_voters: 1@web.example.com:8080,2@web.example.com:8081,3@web.example.com:8082
  - cq_voters: 1@web.example.com:8080,2@web.example.com:8081,3@web.example.com:8082
listeners:
  - listeners: SASL_SSL://web.example.com:18080,CONTROLLER://web.example.com:8080
  - listeners: SASL_SSL://web.example.com:18081,CONTROLLER://web.example.com:8081
advertised:
  - advertised_listeners: SASL_SSL://web.example.com:18080
  - advertised_listeners: SASL_SSL://web.example.com:18081
log_dir:
  - log_dir: /tmp/server1/kraft-combined-logs
  - log_dir: /tmp/server2/kraft-combined-logs

server.properties（模板文件） #

node.id= "{{ node_id }}"
controller.quorum.voters= "{{ cqvoters }}"
############################# Socket Server Settings #############################
listeners= "{{ listeners }}"
advertised.listeners= "{{ advertised }}"
############################# Log Basics #############################
log.dirs= "{{ log_dir }}"

问题根源在于变量结构设计不合理：每个配置项单独维护成列表，无法保证循环时各列表的索引对应正确，且现有Playbook没有做循环遍历生成多个文件的逻辑。以下是修正步骤：

1. 重构变量文件common.yml #

将每个服务器的所有配置整合成一个列表项，确保每个服务器的参数绑定在一起：

---
servers:
  - server_no: 1
    node_id: 1
    cq_voters: 1@web.example.com:8080,2@web.example.com:8081,3@web.example.com:8082
    listeners: SASL_SSL://web.example.com:18080,CONTROLLER://web.example.com:8080
    advertised_listeners: SASL_SSL://web.example.com:18080
    log_dir: /tmp/server1/kraft-combined-logs
  - server_no: 2
    node_id: 2
    cq_voters: 1@web.example.com:8080,2@web.example.com:8081,3@web.example.com:8082
    listeners: SASL_SSL://web.example.com:18081,CONTROLLER://web.example.com:8081
    advertised_listeners: SASL_SSL://web.example.com:18081
    log_dir: /tmp/server2/kraft-combined-logs

2. 修改Main.yml的Playbook逻辑 #

添加循环遍历servers列表，每次渲染模板生成对应服务器的配置文件：

---
- name: Create server properties files
  hosts: localhost
  become: yes
  become_user: root
  gather_facts: true
  vars:
    t_file: server.properties.j2  # 模板文件名改为j2后缀更规范
    t_dir: /path/to/save/newfiles
  tasks:
    - name: Include vars file
      include_vars:
        file: common.yml

    - name: Generate server properties files
      template:
        src: "{{ t_file }}"
        dest: "{{ t_dir }}/server{{ item.server_no }}.properties"
        mode: 0644
      loop: "{{ servers }}"
      # 将当前循环项的参数传递给模板
      vars:
        node_id: "{{ item.node_id }}"
        cqvoters: "{{ item.cq_voters }}"
        listeners: "{{ item.listeners }}"
        advertised: "{{ item.advertised_listeners }}"
        log_dir: "{{ item.log_dir }}"

3. 修正模板文件server.properties.j2 #

去掉多余的引号，直接引用变量（Jinja2渲染时会自动替换为实际值）：

node.id= {{ node_id }}
controller.quorum.voters= {{ cqvoters }}
############################# Socket Server Settings #############################
listeners= {{ listeners }}
advertised.listeners= {{ advertised }}
############################# Log Basics #############################
log.dirs= {{ log_dir }}

内容的提问来源于stack exchange，提问作者Arun Karthick V