![Ansible result.failed 与 failed_when、result.changed 与changed_when 等](https://linux22.com/image/128487/Ansible%20result.failed%20%E4%B8%8E%20failed_when%E3%80%81result.changed%20%E4%B8%8Echanged_when%20%E7%AD%89.png)
Ansible 在 1.4 及更高版本中提供了一种指定此行为的方法,如下所示:
- name: Fail task when the command error output prints FAILED command: /usr/bin/example-command -x -y -z register: command_result failed_when: "'FAILED' in command_result.stderr"
但常见的返回值已经包括.failed
和.changed
。
在我看来,这些特征是相互矛盾的。有官方解决方案吗? Ansible 是否将其中之一定义failed_when
为changed_when
首先评估并影响后者?它是否定义了对两者进行评估而没有看到对方的效果?
例如,定义的行为是什么
command_result.failed
failed_when
在表达式内command_result.changed
changed_when
在表达式内command_result.failed
changed_when
在表达式内command_result.changed
changed_when
在表达式内
更清楚地说,例如对于第三个,我感兴趣的是以下结果的定义如何明确(可靠):
- package:
name: systemd
state: present
check_mode: yes
register: command_result
failed_when: command_result.changed
假设我对 Ansible 2.0 及更高版本感兴趣。
答案1
这看起来不对
您的示例为您的剧本添加了另一条路径。如果未安装 systemd,则输出将与安装时不同。第一次运行后它将被安装。这违背了 ansible 原则:
幂等性
如果执行一次操作的结果与重复执行操作而无需任何干预操作的结果完全相同,则该操作是幂等的。
如果你仍然这样做,请尽可能明确
我建议您运行命令which systemctl
并注册输出。检查输出以安装 systemd 并失败并显示失败任务。
这仍然是一个非常有趣的问题
我想没有真正的文件,我们必须调查。
我希望我抓住了所有案例:)但我现在无法填写图表。
剧本.yml:
---
- name: test some stuff
hosts: all
tasks:
- include_tasks: tasks.yml
with_items:
- { data: ping, changed: true }
- { data: ping, changed: false }
- { data: crash, changed: true }
- { data: crash, changed: false }
任务.yml
---
- name: Check for command_result is defined and command_result
ping:
data: "{{ item.data }}"
register: command_result
changed_when: item.changed
failed_when: command_result is defined and command_result
ignore_errors: true
- name: Check for command_result is defined and command_result
file:
path: ./file
register: command_result
changed_when: item.changed
failed_when: command_result is defined and command_result
ignore_errors: true
- name: Check for command_result
ping:
data: "{{ item.data }}"
register: command_result
changed_when: item.changed
failed_when: command_result
ignore_errors: true
- name: Check for command_result
file:
path: ./file
register: command_result
changed_when: item.changed
failed_when: command_result
ignore_errors: true
- name: Check for command_result.changed is defined and command_result.changed
ping:
data: "{{ item.data }}"
register: command_result
changed_when: item.changed
failed_when: command_result.changed is defined and command_result.changed
- name: Check for command_result.changed is defined and command_result.changed
ping:
data: "{{ item.data }}"
register: command_result
changed_when: item.changed
failed_when: command_result.changed is defined and command_result.changed
ignore_errors: true
- name: Check for command_result.changed
ping:
data: "{{ item.data }}"
register: command_result
changed_when: item.changed
failed_when: command_result.changed
ignore_errors: true
- name: Check for command_result.changed
file:
path: ./file
register: command_result
changed_when: item.changed
failed_when: command_result.changed
ignore_errors: true