如何用Ansible或yq一键生成{{}}变量替换后的YAML文件？

我有多个类似如下内容的serverlist_xzy.yml文件：

all:
  children:
    web:
      hosts:
        srv-proxy-01:
          isWeb: true
  vars:
    zf_env: 'preprod'
    zf_zone: 'global'
    project_path:
      api: "proj_api_{{ zf_zone }}_{{ zf_env }}"
      data: "proj_data_{{ zf_zone }}_{{ zf_env }}"
      web: "proj_web_{{ zf_zone }}_{{ zf_env }}"
      flower: "proj_flower_{{ zf_zone }}_{{ zf_env }}"
    root_path:
      api: "/opt/{{ project_path['api'] }}"
      web: "/opt/{{ project_path['web'] }}"
      data: "/opt/{{ project_path['data'] }}"
    lazy_table: "{{ root_path['data'] }}/data_lazy_table"
    logrotate_logpath:
      api: "/var/log/{{ project_path['api'] }}_app"
      web: "/var/log/{{ project_path['web'] }}_app"
      worker: "/var/log/aaa_worker_{{ zf_zone }}_{{ zf_env }}_app"
      flower: "/var/log/{{ project_path['flower'] }}_app"
    htpasswd:
      path:
        api: "/etc/nginx/passwords/{{ project_path['api'] }}.passwdfile"
        web: "/etc/nginx/passwords/{{ project_path['web'] }}.passwdfile"
        flower: "/etc/nginx/passwords/{{ project_path['flower'] }}.passwfile"

需要将文件中所有{{}}形式的变量替换后输出到out.yml，最终效果示例：

$ grep worker out.yml
      worker: "/var/log/aaa_worker_global_preprod_app"

可以用Python实现，但想知道是否能用Ansible或yq一键完成该操作。

一、用Ansible实现 #

Ansible原生支持Jinja2模板渲染，完美匹配需求中的{{}}变量语法，操作步骤如下：

1. 编写Playbook文件
   创建render_vars.yml文件：

- name: 渲染YAML变量到输出文件
  hosts: localhost
  gather_facts: no
  tasks:
    - name: 读取原YAML文件内容
      slurp:
        src: serverlist_xzy.yml
      register: yaml_raw

    - name: 解析并渲染变量，写入目标文件
      copy:
        content: "{{ yaml_raw.content | b64decode | from_yaml | to_nice_yaml }}"
        dest: out.yml

2. 执行Playbook
   直接运行命令：

ansible-playbook render_vars.yml

该方法会自动解析文件内的所有Jinja2变量，包括嵌套引用的变量，最终输出格式化后的完整YAML到out.yml。

二、用yq实现 #

yq支持自定义字符串替换逻辑，需手动处理变量的嵌套关系，步骤如下：

1. 提取基础变量值
   先从原文件中获取核心变量：

zf_env=$(yq '.all.vars.zf_env' serverlist_xzy.yml | tr -d "'")
zf_zone=$(yq '.all.vars.zf_zone' serverlist_xzy.yml | tr -d "'")

2. 递归替换所有变量
   使用yq的eval命令完成全量替换：

yq eval '
  .all.vars.project_path.api |= sub("{{ zf_zone }}_{{ zf_env }}"; env(zf_zone) + "_" + env(zf_env)) |
  .all.vars.project_path.data |= sub("{{ zf_zone }}_{{ zf_env }}"; env(zf_zone) + "_" + env(zf_env)) |
  .all.vars.project_path.web |= sub("{{ zf_zone }}_{{ zf_env }}"; env(zf_zone) + "_" + env(zf_env)) |
  .all.vars.project_path.flower |= sub("{{ zf_zone }}_{{ zf_env }}"; env(zf_zone) + "_" + env(zf_env)) |
  .all.vars.root_path.api |= sub("{{ project_path['api'] }}"; .all.vars.project_path.api) |
  .all.vars.root_path.web |= sub("{{ project_path['web'] }}"; .all.vars.project_path.web) |
  .all.vars.root_path.data |= sub("{{ project_path['data'] }}"; .all.vars.project_path.data) |
  .all.vars.lazy_table |= sub("{{ root_path['data'] }}"; .all.vars.root_path.data) |
  .all.vars.logrotate_logpath.api |= sub("{{ project_path['api'] }}"; .all.vars.project_path.api) |
  .all.vars.logrotate_logpath.web |= sub("{{ project_path['web'] }}"; .all.vars.project_path.web) |
  .all.vars.logrotate_logpath.worker |= sub("{{ zf_zone }}_{{ zf_env }}"; env(zf_zone) + "_" + env(zf_env)) |
  .all.vars.logrotate_logpath.flower |= sub("{{ project_path['flower'] }}"; .all.vars.project_path.flower) |
  .all.vars.htpasswd.path.api |= sub("{{ project_path['api'] }}"; .all.vars.project_path.api) |
  .all.vars.htpasswd.path.web |= sub("{{ project_path['web'] }}"; .all.vars.project_path.web) |
  .all.vars.htpasswd.path.flower |= sub("{{ project_path['flower'] }}"; .all.vars.project_path.flower)
' serverlist_xzy.yml > out.yml

该方法适合变量结构固定的场景，若嵌套层次多，Ansible方案会更高效省心。

内容的提问来源于stack exchange，提问作者user3313834