knowledge/technology/tools/Ansible/modules/ansible.builtin.assert.md

# ansible.builtin.assert
This module asserts that given expressions are true with an optional custom message

## Parameters
| Parameter   | Type                              | Description                                                                              |
| ----------- | --------------------------------- | ---------------------------------------------------------------------------------------- |
| **fail_msg**    | string                            | The customized message used for a failing assertion                                      |
| **quiet**       | boolean                           | Set this to `true` to avoid verbose output                                               |
| **success_msg** | string                            | The customized message used for a successful assertion                                   |
| **that**       | list / elements=string / required | A list of string expressions of the same form that can be passed to the ‘when’ statement | 

## Examples
```yaml
- ansible.builtin.assert: { that: "ansible_os_family != 'RedHat'" }

- ansible.builtin.assert:
    that:
      - "'foo' in some_command_result.stdout"
      - number_of_the_counting == 3

- name: After version 2.7 both 'msg' and 'fail_msg' can customize failing assertion message
  ansible.builtin.assert:
    that:
      - my_param <= 100
      - my_param >= 0
    fail_msg: "'my_param' must be between 0 and 100"
    success_msg: "'my_param' is between 0 and 100"

- name: Please use 'msg' when ansible version is smaller than 2.7
  ansible.builtin.assert:
    that:
      - my_param <= 100
      - my_param >= 0
    msg: "'my_param' must be between 0 and 100"

- name: Use quiet to avoid verbose output
  ansible.builtin.assert:
    that:
      - my_param <= 100
      - my_param >= 0
    quiet: true
```