在 Ansible jinja2 模板中使用查找/动态变量名称

Question

下面的剧本应该生成一个包含以下内容的文件：

a,b
ssh_host_key
ssh_rsa_host_key

但是，我构造变量名的方式导致语法/模板错误或“变量名不存在”：

---
- hosts: localhost
  connection: local

  vars:
    CentOS:
      ciphers: "a,b"
      hostkeys:
        - "ssh_host_key"
        - "ssh_rsa_host_key"
  tasks:
  - copy:
      dest: "{{ playbook_dir }}/test.out"
      content: |

        # This works:
        {{ CentOS.ciphers }}

        # This results in 'No variable found with this name':
        {{ lookup('vars', ansible_distribution + '.ciphers') }}

        # Templating errors:
        {% for hostkey in {{ lookup('vars', ansible_distribution + '.hostkeys') }} %}
        {{ hostkey }}
        {% endfor %}

        # Templating errors:
        {% for hostkey in {{ hostvars[inventory_hostname][ansible_distribution + '.hostkeys'] }} %}
        {{ hostkey }}
        {% endfor %}

“组装”变量名称的正确方法是什么？或者有更好的方法吗？

Answer 1

Ansible 新闻组的 Martin Krizek 回答了我的问题。正确的语法是：

---
- hosts: localhost
  connection: local

  vars:
    CentOS:
      hostkeys:
        - "ssh_host_key"
        - "ssh_rsa_host_key"
  tasks:
  - copy:
      dest: "{{ playbook_dir }}/test.out"
      content: |
        {% for hostkey in lookup('vars', ansible_distribution)['hostkeys'] %}
        {{ hostkey }}
        {% endfor %}