Ansible with_subelements

问题描述

我很难理解 ansible with_subelements 语法的逻辑，with_subelements 到底是做什么的?我在这里查看了关于 with_subelements 的 ansible 文档https://docs.ansible.com/ansible/latest/user_guide/playbooks_loops.html#with-subelements 并没有太大帮助.我还在博客上看到了一个带有 with_subelements 示例的剧本

I am having a hard time understanding the logic of ansible with_subelements syntax, what exactly does with_subelements do? i took a look at ansible documentation on with_subelements here https://docs.ansible.com/ansible/latest/user_guide/playbooks_loops.html#with-subelements and was not very helpful. I also saw a playbook with with_subelements example on a blog

---
- hosts: cent
  vars:
    users:
     - name: jagadish
       comments:
         - 'Jagadish is Good'

     - name: srini
       comments:
         - 'Srini is Bad' 

  tasks:
   - name: User Creation
     shell: useradd -c "{{ item.1 }}" "{{ item.0.name }}"
     with_subelements:
         - users
         - comments

item.1 和 item.0 指的是什么?

what do item.1 and item.0 refer to?

推荐答案

这是 subelements 查找如何工作的一个非常糟糕的例子.(并且还有旧的、不受支持的语法).

This is really bad example of how subelements lookup works. (And has old, unsupported, syntax as well).

看看这个:

---
- hosts: localhost
  gather_facts: no
  vars:
    families:
      - surname: Smith
        children:
          - name: Mike
            age: 4
          - name: Kate
            age: 7
      - surname: Sanders
        children:
          - name: Pete
            age: 12
          - name: Sara
            age: 17

  tasks:
    - name: List children
      debug:
        msg: "Family={{ item.0.surname }} Child={{ item.1.name }} Age={{ item.1.age }}"
      with_subelements:
        - "{{ families }}"
        - children

Task List children 就像是对 families 列表(外循环)和每个系列中的 children 子元素(内循环)的嵌套循环.
所以你应该提供一个字典列表作为 subelements 的第一个参数和你想要在每个外部项目中迭代的子元素的名称.

Task List children is like a nested loop over families list (outer loop) and over children subelement in each family (inner loop).
So you should provide a list of dicts as first argument to subelements and name of subelement you want to iterate inside each outer item.

这样item.0(在我的例子中是family)是一个外部项目，而item.1(在我的例子中是child)是一个内部项目.

This way item.0 (family in my example) is an outer item and item.1 (child in my example) is an inner item.

在 Ansible 文档示例中，subelements 用于遍历用户(外部)并添加多个公钥(内部).

In Ansible docs example subelements is used to loop over users (outer) and add several public keys (inner).

这篇关于Ansible with_subelements的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！