ansible - 使用Ansible : How to get stderr and stdout from failing commands to be printed respecting newlines so as to be human readable?进行调试

Question

如果我运行一个简单的ansible剧本，那么经常会从失败的任务中获得难以阅读的输出，如下所示。大问题:

标准输出中的换行符打印为\n，而不是实际的换行符。这使得诸如python追溯之类的东西非常令人讨厌。

stdout，stderr，cmd ...输出的json blob包含很多有用的东西，但是由于它们都在同一行上一起运行，因此
人类很难解析。

我如何能以易于阅读的格式打印其输出，以便进行调试？

这是令人讨厌的输出:

$ ansible-playbook playbooks/backUpWebsite.yml

PLAY [localhost] 
***************************************************************

TASK [command] 
*****************************************************************
fatal: [localhost]: FAILED! => {"changed": true, "cmd": "python -c 'ksjfasdlkjf'", "delta": "0:00:00.037459", "end": "2017-10-03 19:58:50.525257", "failed": true, "rc": 1, "start": "2017-10-03 19:58:50.487798", "stderr": "Traceback (most recent call last):\n  File \"<string>\", line 1, in <module>\nNameError: name 'ksjfasdlkjf' is not defined", "stdout": "", "stdout_lines": [], "warnings": []}
        to retry, use: --limit @<snip>playbooks/backUpWebsite.retry

PLAY RECAP 
*********************************************************************
localhost                  : ok=0    changed=0    unreachable=0 failed=1   

这是生成它的脚本:

---
- hosts: localhost
  gather_facts: False
  tasks:
      #wrong on purpose!
    - shell: "python -c 'ksjfasdlkjf'"
      register: unobtainable

Answer 1

为了能够尊重输出中的换行符，以便您可以读取失败任务的标准输出，将stdout_callback更改为“minimum”。

在您的ansible.cfg中，更改stdout_callback选项:

stdout_callback=minimal

“最小”输出有点简洁，但是它会打印有关换行符的输出，以便您可以看到正在发生的情况:

 $ ansible-playbook playbooks/backUpWebsite.yml
 localhost | FAILED | rc=1 >>
 Traceback (most recent call last):
   File "<string>", line 1, in <module>
 NameError: name 'ksjfasdlkjf' is not defined

         to retry, use: --limit @<snip>/playbooks/backUpWebsite.retry

我听到的其他事情可以起作用

您可以为stdout编写自己的回调处理程序。 People have done this似乎很简单，但是我从未尝试过。

我尝试过的无效的操作:

三个vs 。使用“ansible-playbook -vvv”。您会得到大量输出，其中确实包含json很好的换行符，但是不会输出stdout输出中的换行符，因此仍很难阅读stdout/stderr:

$ ansible-playbook playbooks/backUpWebsite.yml -vvv
Using <snip>/ansible.cfg as config file

PLAYBOOK: backUpWebsite.yml ****************************************************
1 plays in playbooks/backUpWebsite.yml

PLAY [localhost] ***************************************************************

TASK [command] *****************************************************************
task path: <snip>/playbooks/backUpWebsite.yml:6
Using module file <snip>/ansible/lib/ansible/modules/core/commands/command.py
<127.0.0.1> ESTABLISH LOCAL CONNECTION FOR USER: <snip>
<127.0.0.1> EXEC /bin/sh -c 'echo ~ && sleep 0'
<127.0.0.1> EXEC /bin/sh -c '( umask 77 && mkdir -p "` echo <snip>/.ansible/tmp/ansible-tmp-1507083519.4247632-54588405727205 `" && echo ansible-tmp-1507083519.4247632-54588405727205="` echo <snip>/.ansible/tmp/ansible-tmp-1507083519.4247632-54588405727205 `" ) && sleep 0'
<127.0.0.1> PUT /tmp/tmpumtlourx TO <snip>/.ansible/tmp/ansible-tmp-1507083519.4247632-54588405727205/command.py
<127.0.0.1> EXEC /bin/sh -c 'chmod u+x <snip>/.ansible/tmp/ansible-tmp-1507083519.4247632-54588405727205/ <snip>/.ansible/tmp/ansible-tmp-1507083519.4247632-54588405727205/command.py && sleep 0'
<127.0.0.1> EXEC /bin/sh -c '<snip>/anaconda3/bin/python <snip>/.ansible/tmp/ansible-tmp-1507083519.4247632-54588405727205/command.py; rm -rf "<snip>/.ansible/tmp/ansible-tmp-1507083519.4247632-54588405727205/" > /dev/null 2>&1 && sleep 0'
fatal: [localhost]: FAILED! => {
    "changed": true,
    "cmd": "python -c 'ksjfasdlkjf'",
    "delta": "0:00:00.037657",
    "end": "2017-10-03 20:18:39.843933",
    "failed": true,
    "invocation": {
        "module_args": {
            "_raw_params": "python -c 'ksjfasdlkjf'",
            "_uses_shell": true,
            "chdir": null,
            "creates": null,
            "executable": null,
            "removes": null,
            "warn": true
        },
        "module_name": "command"
    },
    "rc": 1,
    "start": "2017-10-03 20:18:39.806276",
    "stderr": "Traceback (most recent call last):\n  File \"<string>\", line 1, in <module>\nNameError: name 'ksjfasdlkjf' is not defined",
    "stdout": "",
    "stdout_lines": [],
    "warnings": []
}
        to retry, use: --limit @<snip>/sys/ansible_readynet/playbooks/backUpWebsite.retry

PLAY RECAP *********************************************************************
localhost                  : ok=0    changed=0    unreachable=0    failed=1   

信用

I posted this issue反对github上的ansible，希望说服人们使用ansible的默认值是无济于事的。 jhawkesworth帮助我介绍了“最小” stdout回调。

此后，我发现 this page in the ansible documentation以非常非突出的方式提及了此插件。

恕我直言，从ansible获取可读取错误输出的 secret 对于新用户来说太隐秘了，我亲眼目睹了我认识的使用ansible的一些人。