Need to map json to list - ansible

Question

I have register variable with below json as value and need to extract name and dn from this JSON to list. tried different options using set_fact without any luck.
{
"nodes": {
"status": -1,
"imdata": [
{
"fabricNode": {
"attributes": {
"status": "",
"dn": "topology/pod-1/node-1",
"name": "NOQCJALAB1"
}
}
},
{
"fabricNode": {
"attributes": {
"status": "",
"dn": "topology/pod-1/node-1",
"name": "NOQCJALAB2"
}
}
}
],
"totalCount": 2,
"changed": false,
"failed": false
},
"changed": false,
"_ansible_verbose_always": true,
"_ansible_no_log": false
}

Answer 1

You need to remove the extraneous calls to map('from_json') because the object is already a dict
- set_fact:
node_names: >-
{{ (nodes.stdout | from_json).data
| map(attribute='fabnode')
| map(attribute='attributes')
| map(attribute='dn')
| list
}}
You would only want those map('from_json') call if your data structure contained embedded JSON, like so:
- set_fact:
inner_value: >-
{{ (example_text | from_json).a_key
| map("from_json")
| map(attribute="inner_key")
| list
}}
vars:
example_text: |
{"a_key": ["{\"inner_key\": \"inner value\"}"]}

Answer 2

It's possible to use json_query. For example the tasks below
- set_fact:
my_list: "{{ nodes.imdata|
json_query('[].{dn: fabricNode.attributes.dn,
name: fabricNode.attributes.name}')
}}"
- debug:
var: my_list
give
"my_list": [
{
"dn": "topology/pod-1/node-1",
"name": "NOQCJALAB1"
},
{
"dn": "topology/pod-1/node-1",
"name": "NOQCJALAB2"
}
]