Ansible跨Windows/Linux剧本角色条件引用语法错误求助

编写同时适配Windows和Linux系统的Ansible Playbook时，尝试根据操作系统类型条件性引入角色，始终遭遇语法报错，多次调整写法均失败，附上相关代码及报错信息求助。

原Playbook代码 #

---
- hosts: all
  gather_facts: no
  pre_tasks:
    - name: (localhost) 清空known_hosts文件
      lineinfile:
        path: ~/.ssh/known_hosts
        state: absent
        regexp: "^{{ ansible_host | replace('.', '\\\\.') }}.*$"
      delegate_to: 127.0.0.1

- hosts: all
  serial: 1
  pre_tasks:
    - name: (debug) 打印调试信息确认Inventory配置
      debug:
        msg: "System inventory_hostname:{{ inventory_hostname }} ansible_host:{{ ansible_host }}"

- hosts: all
  tasks:
  - name: 安装Windows CA信任证书
    include_tasks: tasks\\install-certs-windows.yml
    when: ansible_os_family == 'Windows'

  - name: 安装Linux CA信任证书
    include_tasks: tasks/install-certs-linux.yml
    when: ansible_os_family != 'Windows'

  roles:
  - { role: ansible-role-runnersbasics, tags: ["basics"] }
  - { role: ansible-role-docker, tags: ["docker"] }
  - { role: ansible-role-gitlab-runner }
    when: ansible_os_family == 'Windows'

首次报错信息 #

ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)

Syntax Error while loading YAML.
  did not find expected key

The error appears to be in 'playbook.yml': line 33, column 5, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

  - { role: ansible-role-gitlab-runner }
    when: ansible_os_family == 'Windows'
    ^ here

修改写法后的报错信息 #

ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)

Syntax Error while loading YAML.
  mapping values are not allowed in this context

The error appears to be in 'playbook.yml': line 30, column 43, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

  roles:
    role: ansible-role-runnersbasics, tags: ["basics"] }
                                          ^ here

错误原因及修复方案 #

1. 首次报错的核心问题 #

YAML语法规则要求：角色的条件判断when必须和角色定义放在同一个映射（字典）结构中，不能单独作为下一行的独立键。原写法中- { role: ansible-role-gitlab-runner }是一个完整的列表项，下一行的when无法被解析为该角色的属性，导致语法错误。

修复方式：将when条件合并到角色的字典定义中，两种写法任选其一：

• 紧凑字典格式：

  - { role: ansible-role-gitlab-runner, when: ansible_os_family == 'Windows' }
  

• 展开多行格式（可读性更强）：

  - role: ansible-role-gitlab-runner
    when: ansible_os_family == 'Windows'
  

2. 修改后报错的问题 #

修改时破坏了YAML字典的语法结构，正确的角色列表写法要么用完整的{ key: value, key: value }格式，要么用多行展开格式，不能混合错误的括号和逗号。

3. 额外注意事项 #

你的Playbook中设置了gather_facts: no，但后续用到了ansible_os_family这个系统事实变量，这会导致变量未定义的错误。必须开启事实收集：

• 要么删除gather_facts: no（默认值为yes）
• 要么在pre_tasks中手动添加事实收集任务：

  - name: 收集系统事实信息
    setup:
  

修复后的完整角色部分代码 #

roles:
  - { role: ansible-role-runnersbasics, tags: ["basics"] }
  - { role: ansible-role-docker, tags: ["docker"] }
  - role: ansible-role-gitlab-runner
    when: ansible_os_family == 'Windows'

内容的提问来源于stack exchange，提问作者crNh