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ansiblejsonpathjson-query

Complex JSON and Ansible JSON_QUERY syntax


i have complex result in JSON format and struggling to extract values out of it. I tested the JSONpath online evaluator https://jsonpath.com/ where i can just simply type

$.[*].toPort

and get the list of requested variables.

I've tried to use the same syntax in Ansible but getting empty list.

- name: JSON test
  hosts: localhost
  gather_facts: no

  vars:
    jsoncontent:
                {
                        "infraAccPortP": {
                            "attributes": {
                                "annotation": "",
                                "childAction": "",
                                "descr": "",
                                "nameAlias": "",
                                "ownerKey": "",
                                "ownerTag": "",
                                "status": "",
                                "uid": "15374"
                            },
                            "children": [
                                {
                                    "infraHPortS": {
                                        "attributes": {
                                            "annotation": "",
                                            "uid": "8927"
                                        },
                                        "children": [
                                            {
                                                "infraPortBlk": {
                                                    "attributes": {                                                  
                                                        "fromPort": "41",
                                                        "toPort": "41",
                                                        "uid": "8927"
                                                    }
                                                }
                                            }
                                        ]
                                    }
                                },
                                {
                                    "infraHPortS": {
                                        "attributes": {
                                            "annotation": "",
                                            "uid": "8927"
                                        },
                                        "children": [
                                            {
                                                "infraPortBlk": {
                                                    "attributes": {
                                                        "fromPort": "42",
                                                        "toPort": "42",
                                                        "uid": "8927"
                                                    }
                                                }
                                            }
                                        ]
                                    }
                                }
                            ]
                        }
                    }

  tasks:
    - name: show jsoncontent
      debug:
        var: jsoncontent

    - name: Show just toPort values
      debug: 
        msg: "{{ jsoncontent | json_query(jmesquery)    }}"
      vars:
        jmesquery: "[*].toPort"

Any help how to adjust the query to get the expected result? Its bit frustrating as there is not much documentation on how json_query is implemented in Ansible


Solution

  • The task below does the job

        - name: Show just toPort values
          debug: 
            msg: "{{ jsoncontent.infraAccPortP.children | json_query(jmesquery) }}"
          vars:
            jmesquery: "[].infraHPortS.children[].infraPortBlk.attributes.toPort"
    

    gives

      msg:
      - '41'
      - '42'
    

    Q: "Ansible implementation doesn't allow wildcard searches?"

    A: There doesn't seem to be anything special in the implementation. (This filter moved to ansible-collections/community.general since 2.10.)


    Q: "Just confused why I got the same result with much shorter syntax in that online checker."

    A: The question is how the checker is implemented, I think. jq doesn't work this way either. For example

    shell> cat data.json | jq .jsoncontent.infraAccPortP.children[].infraHPortS.children[].infraPortBlk.attributes.toPort
    "41"
    "42"
    

    The "checker" query crashes

    shell> cat data.json | jq .[*].toPort
    jq: error: syntax error, unexpected '*' (Unix shell quoting issues?) at <top-level>, line 1:
    .[*].toPort  
    jq: 1 compile error
    

    , or gives an empty result

    shell> cat data.json | jq .[].toPort
    null