Ansible:检查变量是否包含列表或字典

Question

有时，角色需要在调用它们时需要定义不同的强制变量。例如

- hosts: localhost
  remote_user: root

  roles:
    - role: ansible-aks
      name: myaks
      resource_group: myresourcegroup

在角色内部，可以这样控制:

- name: Assert AKS Variables
  assert:
    that: "{{ item }} is defined"
    msg: "{{ item  }} is not defined"
  with_items:
    - name
    - resource_group

我想将列表或字典而不是字符串传递给我的角色。如何断言变量包含字典或列表？

Answer 1

例子:

在字典的情况下，很容易:

---
- name: Assert if variable is list or dict
  hosts: localhost
  connection: local
  gather_facts: false

  vars:
    mydict: {}
    mylist: []

  tasks:

  - name: Assert if dictionary
    assert:
      that: ( mydict is defined ) and ( mydict is mapping )

但是在检查列表时，我们需要确保它不是映射，不是字符串和可迭代的:

  - name: Assert if list
    assert:
      that: >
           ( mylist is defined ) and ( mylist is not mapping )
           and ( mylist is iterable ) and ( mylist is not string )

如果您使用字符串、 bool 值或数字进行测试，则断言将为假。

另一个不错的选择是:

  - name: Assert if dictionary
    assert:
      that: ( mydict is defined ) and ( mydict | type_debug == "dict" )

  - name: Assert if list
    assert:
      that: ( mylist is defined ) and ( mylist | type_debug == "list" )