loops - 如何在 Ansible 中获取子组列表？

Question

我有一个看起来像这样的 list 文件:

[master]
host01

[nl]
host02

[us]
host03

[satellites:children]
nl
us

如何获得具有 satellites 的组列表作为他们的 parent ？

我正在寻找与此类似的解决方案:

- debug: msg="{{ item }}"
  with_items: "{{ groups['satellites:children'] }}"

更新:

我能够提出的唯一解决方案是:

- debug: {{ item }}
  with_items: "{{ groups }}"
  when: item != "master" and item != "satellites" and item != "all" and item != "ungrouped"

但这不是很灵活。

Answer 1

您可以尝试以下方法:

  vars:
    parent: 'satellites'
  tasks:
      # functional style
    - debug: msg="{{hostvars[item].group_names | select('ne', parent) | first}}"
      with_items: "{{groups[parent]}}"
      # set style
    - debug: msg="{{hostvars[item].group_names | difference(parent) | first}}"
      with_items: "{{groups[parent]}}"

还有 select('ne', parent)可与 reject('equalto', parent) 互换取决于对您来说更易读的内容。

链接:
set theory operator
select and reject filters

根据评论更新答案。灵感来自 this thread .

vars:
    parent: 'satellites'
tasks:
    - name: build a subgroups list
      set_fact: subgroups="{{ ((subgroups | default([])) + hostvars[item].group_names) | difference(parent) }}"
      with_items: "{{groups[parent]}}"

    - debug: var=subgroups

输出:

 "subgroups": [
        "nl",
        "us"
    ]