set_fact create a list with items

Question

I have task which calls an API and I register the o/p in a varaible;

- name: Get Object storage account ID
  uri:
    url: 'https://api.softlayer.com/rest/v3.1/SoftLayer_Network_Storage_Hub_Cleversafe_Account/getAllObjects.json?objectFilter={"username":{"operation":"{{ item }}"}}'
    method: GET
    user: abxc
    password: 66c94c447a6ed8a0cf058774fe38
    validate_certs: no
  register: old_existing_access_keys_sl
  with_items: '{{ info["personal"].sl_cos_accounts }}'

old_existing_access_keys_sl holds:

"old_existing_access_keys_sl.results": [
 {
            "json": [
                {
                    "accountId": 12345, 
                    "id": 70825621, 
                    "username": "xyz-11"
                }
            ]
},
{
            "json": [
                {
                    "accountId": 12345, 
                    "id": 70825621, 
                    "username": "abc-12"
                }
            ]
}

I want to make a list of id's for further processing an tried the following task but this did not work:

- name: Create a list of account ids
  set_fact: 
    admin_usernames = "{{ item.json[0].id | list }}"
  with_items: old_existing_access_keys_sl.results

I am not sure if that's even possible. I also tried this:

    - name: create a list
      set_fact:
         foo: "{% set foo = [] %}{% for i in old_existing_access_keys_sl.results %}{{ foo.append(i) }}{% endfor %}"

foo always comes as blank and as a string:

TASK [result] *****************************************************************************************************************************************
ok: [localhost] => {
    "foo": ""
}

Answer 1

Given your example data, you can extract a list of ids using the json_query filter, like this:

---
- hosts: localhost
  gather_facts: false
  vars:
    old_existing_access_keys_sl:
      results:
        [
          {
            "json": [
              {
                "accountId": 12345,
                "id": 70825621,
                "username": "xyz-11"
              }
            ]
          },
          {
            "json": [
              {
                "accountId": 12345,
                "id": 70825621,
                "username": "abc-12"
              }
            ]
          }
        ]
  tasks:
    - debug:
        var: old_existing_access_keys_sl|json_query('results[*].json[0].id')

This will output:

TASK [debug] **********************************************************************************************************************************************************************************
ok: [localhost] => {
    "old_existing_access_keys_sl|json_query('results[*].json[0].id')": [
        70825621, 
        70825621
    ]
}

If you want to store these in a new variable, you can replace that debug task with set_fact:

    - set_fact:
        admin_ids: "{{ old_existing_access_keys_sl|json_query('results[*].json[0].id') }}"

Update

For a list of dictionaries, just change the json_query expression:

- debug:
    var: "old_existing_access_keys_sl|json_query('results[*].json[0].{id: id, username: username}')"

For more information, see the jmespath website for documentation and examples.