带有包含的json格式查询

Question

我在ansible中有以下json输出：

[{
    "active_transaction": null,
    "cores": 4,
    "hostname": "alpha-auth-wb01"
},
{
    "active_transaction": null,
    "cores": 4,
    "hostname": "beta-auth-wb01"
}]

现在我正在尝试过滤输出以仅显示主机名包含 alpha 的输出。

输出应该是：

[{
    "active_transaction": null,
    "cores": 4,
    "hostname": "alpha-auth-wb01"
}]

代码和结果：

Ansible 代码

jq: "[?contains(hostname, 'alpha')]"


fatal: [worker.domain]: FAILED! => {"msg": "JMESPathError in json_query filter plugin:\\nIn function contains(), invalid type for value: None, expected one of: ['array', 'string'], received: \\"null\\""}

还尝试添加 from_json | to_json 反之亦然。还是失败了。

任何想法都非常感谢！

Answer 1

As @Matthew L Daniel mentioned, you should store your query in a variable, because of quoting issues. Also your query is incorrect, for what you want. As I understood, you would like to select all elements, where the hostname contains the string alpha. A fully working solution is the following:

---
- hosts: localhost
  gather_facts: False

  vars:
    jq: "[?contains(hostname, 'alpha')]"
    json: |
      [{
          "active_transaction": null,
          "cores": 4,
          "hostname": "alpha-auth-wb01"
      },
      {
          "active_transaction": null,
          "cores": 4,
          "hostname": "beta-auth-wb01"
      }]

  tasks:
  - name: DEBUG
    debug:
      msg: "{{ json | from_json | json_query(jq) }}"

If you don't want to write your json_query in a var you could quote it like this:

"{{ json | json_query(\"[?contains(hostname, 'alpha')]\") }}"

But I would recommend, to put it in a var.