ansiblejson-query

Extract "name" from the list of dicts in Ansible


I have the following dictionary:

"dict": [ {   "name": "a",   "surname": "b" }, {   "name": "c",   "surname": "d" }, {   "name": "e",   "surname": "f" } ]

I am trying to extract just "name" values into one list like this one:

names_list: ["a","c","e"]

It should be very simple but I'm not getting the result. This is what I tried:

- set_fact: 
    names_list: "{{ dict | json_query('[*].name') }}"

and also:

- set_fact: 
    names_list: "{{ dict | map(attribute='name') | list }}"

but I'm getting either "none" or "ansible undefined".

What I'm missing here?

Thanks.


Solution

  • Short answer: Rename the variable dict.

    Details: In Ansible 2.14.3, Python 3.9.16, jinja version = 3.1.2 both options work as expected

        - set_fact:
            names_list1: "{{ dict|map(attribute='name')|list }}"
            names_list2: "{{ dict|json_query('[*].name') }}"
    

    give

      names_list1: [a, c, e]
      names_list2: [a, c, e]
    

    But, I got the warning:

    [WARNING]: Found variable using reserved name: dict


    Example of a complete playbook for testing

    - hosts: localhost
    
      vars:
    
        dict:
          - {name: a, surname: b}
          - {name: c, surname: d}
          - {name: e, surname: f}
    
        # names_list1: "{{ dict|map(attribute='name')|list }}"
        # names_list2: "{{ dict|json_query('[*].name') }}"
        
      tasks:
    
        - set_fact:
            names_list1: "{{ dict|map(attribute='name')|list }}"
            names_list2: "{{ dict|json_query('[*].name') }}"
        
        - debug:
            var: names_list1|to_yaml
        - debug:
            var: names_list2|to_yaml