debugging - 如何检查注册变量在ansible中是否具有特定模式？

Question

所以我想检查nginx语法是否正确

- name: check if syntax is ok on nginx
  shell: nginx -t
  register: result

然后我想将其与带有“when:”条件的服务模块一起使用，以运行服务模块来重新加载nginx“when:”“结果”中有“语法正确”。

这样的东西有用吗？

when: result.stdout_lines == "syntax is ok"

Answer 1

你可以使用这样的东西，

when: result.stdout | search("syntax is ok")

它将在 result.stdout 字符串中搜索字符串“syntax is ok”，如果找到，则条件将成功并运行所需的任务(如果找到)如果失败，则任务将被跳过。

我添加了更多方法来达到相同的结果，

when: result.stdout is search("syntax is ok")

使用正则表达式搜索

when: result.stdout | regex_search("syntax is ok")

也可以使用@TinaC建议的。

在ansible版本2.8.0上测试

测试 ansible 剧本

---
- hosts: all
  gather_facts: no
  vars:
    - error_msg: "nginx: [alert] could not open error log file: open() \"/var/log/nginx/error.log\" failed (13: Permission denied) 2019/09/12 16:19:28 [warn] 5343#0: the \"user\" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:5 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok 2019/09/12 16:19:28 [emerg] 5343#0: open() \"/run/nginx.pid\" failed (13: Permission denied) nginx: configuration file /etc/nginx/nginx.conf test failed"
  tasks:
    - debug:
        msg: "{{ error_msg }}"

    - debug:
        msg: "{{ error_msg }}"
      when: error_msg | search("syntax is ok")

    - debug:
        msg: "{{ error_msg }}"
      when: error_msg is search("syntax is ok")

    - debug:
        msg: "{{ error_msg }}"
      when: error_msg | regex_search("syntax is ok")

输出

PLAY [all] ***********************************************************************************************************************************************

TASK [debug] *********************************************************************************************************************************************
ok: [192.168.100.101] => {
    "msg": "nginx: [alert] could not open error log file: open() \"/var/log/nginx/error.log\" failed (13: Permission denied) 2019/09/12 16:19:28 [warn] 5343#0: the \"user\" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:5 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok 2019/09/12 16:19:28 [emerg] 5343#0: open() \"/run/nginx.pid\" failed (13: Permission denied) nginx: configuration file /etc/nginx/nginx.conf test failed"
}

TASK [debug] *********************************************************************************************************************************************
ok: [192.168.100.101] => {
    "msg": "nginx: [alert] could not open error log file: open() \"/var/log/nginx/error.log\" failed (13: Permission denied) 2019/09/12 16:19:28 [warn] 5343#0: the \"user\" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:5 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok 2019/09/12 16:19:28 [emerg] 5343#0: open() \"/run/nginx.pid\" failed (13: Permission denied) nginx: configuration file /etc/nginx/nginx.conf test failed"
}

TASK [debug] *********************************************************************************************************************************************
ok: [192.168.100.101] => {
    "msg": "nginx: [alert] could not open error log file: open() \"/var/log/nginx/error.log\" failed (13: Permission denied) 2019/09/12 16:19:28 [warn] 5343#0: the \"user\" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:5 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok 2019/09/12 16:19:28 [emerg] 5343#0: open() \"/run/nginx.pid\" failed (13: Permission denied) nginx: configuration file /etc/nginx/nginx.conf test failed"
}

TASK [debug] *********************************************************************************************************************************************
ok: [192.168.100.101] => {
    "msg": "nginx: [alert] could not open error log file: open() \"/var/log/nginx/error.log\" failed (13: Permission denied) 2019/09/12 16:19:28 [warn] 5343#0: the \"user\" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:5 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok 2019/09/12 16:19:28 [emerg] 5343#0: open() \"/run/nginx.pid\" failed (13: Permission denied) nginx: configuration file /etc/nginx/nginx.conf test failed"
}

PLAY RECAP ***********************************************************************************************************************************************
192.168.100.101            : ok=4    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

当将字符串 syntax is ok 更改为 syntax is not ok 时，以下是输出，

PLAY [all] ***********************************************************************************************************************************************

TASK [debug] *********************************************************************************************************************************************
ok: [192.168.100.101] => {
    "msg": "nginx: [alert] could not open error log file: open() \"/var/log/nginx/error.log\" failed (13: Permission denied) 2019/09/12 16:19:28 [warn] 5343#0: the \"user\" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:5 nginx: the configuration file /etc/nginx/nginx.conf syntax is not ok 2019/09/12 16:19:28 [emerg] 5343#0: open() \"/run/nginx.pid\" failed (13: Permission denied) nginx: configuration file /etc/nginx/nginx.conf test failed"
}

TASK [debug] *********************************************************************************************************************************************
skipping: [192.168.100.101]

TASK [debug] *********************************************************************************************************************************************
skipping: [192.168.100.101]

TASK [debug] *********************************************************************************************************************************************
skipping: [192.168.100.101]

PLAY RECAP ***********************************************************************************************************************************************
192.168.100.101            : ok=1    changed=0    unreachable=0    failed=0    skipped=3    rescued=0    ignored=0