loops - 我如何遍历 Ansible 中通配符标识的主机

Question

下面是我的剧本，效果很好。

---
- hosts: "PROD_SERVERS"
  user: "{{USER}}"
  tasks:

       - name: Check if all hosts are reachable
         fail:
           msg: "Server is UNREACHABLE."
         when: "hostvars[item].ansible_facts|list|length == 0"
         with_items: "{{ groups.PROD_SERVERS }}"

但是，当主机显示为通配符即 {{ENV}}_* 时，您能帮我解决语法问题吗？ ?

---
- hosts: "{{ENV}}_*"
  user: "{{USER}}"
  tasks:

       - name: Check if all hosts are reachable
         fail:
           msg: "Server is UNREACHABLE."
         when: "hostvars[item].ansible_facts|list|length == 0"
         with_items: "{{ groups.{{ENV}}_* }}"   <------- Need help with this part of the code

Answer 1

有special variables也称为“魔术变量”，用于识别当前播放中的主机。他们是:

ansible_play_hosts

ansible_play_batch

您可以使用这些变量之一代替库存组名称进行循环。
示例与 ansible_play_hosts :

    - fail:
        msg: "Server is UNREACHABLE."
      when: hostvars[item].ansible_facts|list|length == 0
      with_items: "{{ ansible_play_hosts }}"

更新:
更改了 Ansible 版本“2.4.x”的示例，应该使用 with_items 执行循环而不是 loop .引自 official documentation

We added loop in Ansible 2.5. It is not yet a full replacement for with_<lookup>, but we recommend it for most use cases.

注意:对于 Ansible“2.9.16”和“2.10.2” loop也有效。