有没有办法验证 Ansible Inventory 文件中组的主机数量?

问题描述

我的需求如下所示，我有一个 Ansible 清单文件，它根据下面显示的组件分为几组:

My requirement is shown below, I have an Ansible inventory file which is divided into some groups based on the components shown below:

[all]

node1
node2
node3
node4

[webapp]
node3
node4

[ui]
node1

如果条件失败，有没有办法验证库存文件中组的主机数量，那么剧本不应运行?

Is there a way to validate the number of hosts for a group in inventory file if condition fails then playbook should not run ?

我的条件是:ui 组应该总是只有一个主机.

My condition is: ui group should always have only one host.

例如:

[ui]
node1  -- condition check pass proceed with playbook execution

[ui]
node1
node2  -- condition fails should stop playbook execution with exception
          with ui group cannot have more than one hosts

推荐答案

您可以在单个任务中轻松完成:

You can easily do it in a single task:

• 使用 Ansible 魔法变量groups,

将它与 length 过滤器结合 统计ui组中的元素个数，

combine it with length filter to count the number of elements in ui group,

将上述内容插入assert 或 fail 验证和控制流程的模块.

insert the above into an arithmetic comparison conditional in assert or fail module to verify and control the flow.

例如:

- name: Inventory validation
  hosts: localhost
  gather_facts: false
  tasks:
    - assert:
        that:
          - "groups['ui'] | length <= 1"
          - "groups['webapp'] | length <= 1"

但是(这是基于评论)如果您先分配变量，则需要将值转换为整数以进行比较:

But (this is based on comment) if you assign the variables first, you need to cast the value to integer in comparison:

- name: Inventory validation
  hosts: localhost
  gather_facts: false
  vars:
    UI_COUNT: "{{ groups['ui'] | length }}"
    WEBAPP_COUNT: "{{ groups['webapp'] | length }}"
  tasks:
    - assert:
        that:
          - "UI_COUNT | int <= 1"
          - "WEBAPP_COUNT | int <= 1"

这篇关于有没有办法验证 Ansible Inventory 文件中组的主机数量?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！