如何根据变量的值选择Ansible中的主机？

Question

我想使用用户提供的答案在Ansible剧本中选择主机，例如以下伪代码：

---   
- name: feed the machines

  vars_prompt:
    - name: food
      prompt: "Which food do you have? b:Banana, g:grass, m:meat."
      default: "b"
      private: no

  hosts: 'monkeys' if food=='b' else {'cows' if food=='g' else 'lions'}

我知道使用字典也是一种选择。

如何实施它？如果 s或词典有的答案，那将是很高兴的。

Answer 1

您只需要使用正确的jinja表达式模板hosts参数，因此 inline-if if ：

- hosts: "{{ 'monkeys' if food=='b' else 'cows' if food=='g' else 'lions' }}"
  gather_facts: no

  vars_prompt:
    - name: food
      prompt: "Which food do you have? b:Banana, g:grass, m:meat."
      default: "b"
      private: no

哪个会产生：

Which food do you have? b:Banana, g:grass, m:meat. [b]: 

PLAY [monkeys] ***************************************************************

PLAY RECAP *******************************************************************

---

与使食物相对应的词典相同：

- hosts: "{{ food_to_animal[food] }}"
  gather_facts: no

  vars:
    food_to_animal:
      b: monkeys
      g: cows
      m: lions

  vars_prompt:
    - name: food
      prompt: "Which food do you have? b:Banana, g:grass, m:meat."
      default: "b"
      private: no