Ansible：意外的模板类型错误：预期的字符串或缓冲区答案

【问题标题】：Ansible: Unexpected templating type error: expected string or bufferAnsible：意外的模板类型错误：预期的字符串或缓冲区
【发布时间】：2018-11-29 00:04:43
【问题描述】：

我有一个寄存器，内容如下：

ok: [hostname] => {
    "changed": false,
    "msg": {
        "changed": true,
        "cmd": "cd /tmp\n ./status.sh dev",
        "delta": "0:00:00.023660",
        "end": "2018-11-28 17:46:05.838934",
        "rc": 0,
        "start": "2018-11-28 17:46:05.815274",
        "stderr": "",
        "stderr_lines": [],
        "stdout": "application is not running. no pid file found",
        "stdout_lines": [
            "application is not running. no pid file found"
         ]
    }
}

当我在寄存器的标准输出中看到子字符串“not”时，我想触发另一个任务：

  - name: Starting Application As Requested
    shell: /tmp/start.sh
    when: operation_status.stdout | search('not')

但是，我在触发的任务中看到了这个错误

fatal: [host]: FAILED! => {
"failed": true,
"msg": "The conditional check 'operation_status.stdout | search('not')' failed. The error was: Unexpected templating type error occurred on ({% if operation_status.stdout | search('not') %} True {% else %} False {% endif %}): expected string or buffer\n\nThe error appears to have been in '/path/to/ansible_playbook.yml': line 46, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n  - name: Starting Application As Requested\n    ^ here\n"

我只在添加 when 条件时看到此错误。没有它，我的剧本就成功了。我在这里做错了什么？

版本详情：

ansible 2.3.0.0
python version = 2.6.6 (r266:84292, Aug  9 2016, 06:11:56) [GCC 4.4.7 20120313 (Red Hat 4.4.7-17)]

【问题讨论】：

标签： string ansible conditional buffer templating

【解决方案1】：

当变量（在您的情况下为 operation_status.stdout）未定义时会发生此错误。也许status.sh 脚本在服务运行时没有写入标准输出。

你能放一个调试任务，并在任务前用“when”打印这个变量的值吗？

- name: Debug print value of operation_status.stdout
  debug:var=operation_status.stdout

你也可以尝试修改when条件为：

  - name: Starting Application As Requested
    shell: /tmp/start.sh
    when: "'not' in operation_status.stdout"

【讨论】：

你是对的。当我期待它有内容时，我的寄存器结果是空的。谢谢