由于运行时错误，可靠故障模块无法工作

Question

我有一个剧本，其中包含一个为文件中的字符串greps的任务。如果找到字符串，块应该会失败。然而，在救援失败模块内，它无法打印消息并出现错误：

这是我的战术手册：

---
- name: "Play 1"
hosts: localhost
tasks:
- block:
- name: "Search for IP"
command: "grep -w {{ source_host }} {{ playbook_dir }}/allhost.hosts"
register: command_result
failed_when: command_result.rc == 0

rescue:
- name: Print custom conditional debug message
fail:
msg: >-
{{
command_result.rc == 0 |
ternary(
"This IP On-Boarded.",
"The DB is not reachable."
)
}}

我试着换

command_result.rc == 0 |

至

command_result.stdout is search ( source_host ) |

但这也于事无补。

考虑到command_result.rc = 0;，我本以为会打印"This IP is On Boarded."，但事实并非如此。你能告诉我我的剧本出了什么问题吗？

输出：

TASK [Search for IP] *****************************
[1;30mtask path: /tmp/filegaurd.yml:20[0m
[0;34mUsing module file /usr/lib/python2.7/site-packages/ansible/modules/commands/command.py[0m
[0;34mPipelining is enabled.[0m
[0;34m<127.0.0.1> ESTABLISH LOCAL CONNECTION FOR USER: user1[0m
[0;34m<127.0.0.1> EXEC /bin/sh -c '/usr/bin/python2 && sleep 0'[0m
[0;31mfatal: [localhost]: FAILED! => {[0m
[0;31m    "changed": true, [0m
[0;31m    "cmd": [[0m
[0;31m        "grep", [0m
[0;31m        "-w", [0m
[0;31m        "10.9.9.91", [0m
[0;31m        "/tmp/allhost.hosts"[0m
[0;31m    ], [0m
[0;31m    "delta": "0:00:00.096103", [0m
[0;31m    "end": "2020-03-13 07:25:43.705938", [0m
[0;31m    "failed_when_result": true, [0m
[0;31m    "invocation": {[0m
[0;31m        "module_args": {[0m
[0;31m            "_raw_params": "grep -w 10.9.9.91 /tmp/allhost.hosts", [0m
[0;31m            "_uses_shell": false, [0m
[0;31m            "argv": null, [0m
[0;31m            "chdir": null, [0m
[0;31m            "creates": null, [0m
[0;31m            "executable": null, [0m
[0;31m            "removes": null, [0m
[0;31m            "stdin": null, [0m
[0;31m            "stdin_add_newline": true, [0m
[0;31m            "strip_empty_ends": true, [0m
[0;31m            "warn": true[0m
[0;31m        }[0m
[0;31m    }, [0m
[0;31m    "rc": 0, [0m
[0;31m    "start": "2020-03-13 07:25:43.609835", [0m
[0;31m    "stderr": "", [0m
[0;31m    "stderr_lines": [], [0m
[0;31m    "stdout": "10.9.9.91 USERID=user1 files_list=/tmp/winstone4603745991442278706.jar,/tmp/winstone5835113081224811756.jar", [0m
[0;31m    "stdout_lines": [[0m
[0;31m        "10.9.9.91 USERID=user1 files_list=/tmp/winstone460.jar,/tmp/winstone56.jar"[0m
[0;31m    ][0m
[0;31m}[0m

TASK [Print custom conditional debug message] **********************************
[1;30mtask path: /tmp/file.yml:28[0m
[0;31mfatal: [localhost]: FAILED! => {[0m
[0;31m    "changed": false, [0m
[0;31m    "msg": "False "[0m
[0;31m}[0m

PLAY RECAP *********************************************************************
[0;31mlocalhost[0m                  : [0;32mok=1   [0m changed=0    unreachable=0    [0;31mfailed=1   [0m skipped=0    [0;32mrescued=1   [0m ignored=0

Answer 1

jinja过滤运算符|比==更具关联性，实际评估结果是：

command_result.rc == (0 | ternary("This IP On-Boarded.", "The DB is not reachable."))

相当于：

command_result.rc == "The DB is not reachable."

它总是等于False，这就是为什么你得到了输出"msg": "False "。为了解决这个问题，你必须在测试周围使用括号：

(command_result.rc == 0) | ternary("This IP On-Boarded.", "The DB is not reachable.")

请注意，整个过滤器应该在同一条线上。