Retrieve, manipulate and send back JSON in Ansible - json

Question

We have to set and unset a VLAN configuration to a switch. Fortunately, Unify Controller provide an API, which works with Ansible in general.
However, it is not possible with the API to change a single element, Ansible has to get the current configuration, find and change the desired element and send back the configuration. (I pushed the desired config change. This yielded to the situation that the switch had nothing but my config change, I felt like the Facebook guys...)
---
- hosts: adm01.local
gather_facts: false
tasks:
- name: Use vars from Vault
include_vars: unifi_info.yaml
- name: Get Cookie from Unifi
uri:
url: https://{{ url }}/api/login
method: POST
body_format: json
body: {"username":"{{ username }}","password":"{{ password }}"}
validate_certs: false
register: login
- name: Print returned data to ensure it worked
debug:
msg: "{{ login }}"
- name: Get current config
uri:
url: https://{{ url }}/api/s/default/stat/device/
method: GET
body_format: json
headers:
Cookie: "{{ login.cookies_string }}"
validate_certs: false
register: switchConf
- name: Print SwitchConf
debug:
msg: "{{ switchConf }}"
- name: Set port 2 to CLIENTVLAN
uri:
url: https://{{ url }}/api/s/default/rest/device/60acc79964542d80774123b5/
method: PUT
body_format: json
# DISABLE VLAN: "60aca5ee64542d807741239d"
# CLIENTVLAN: ""60accb9b64542d80774123d1"
#body: {"port_overrides": [{"port_idx": 2, "portconf_id":"60accb9b64542d80774123d1"}]}
headers:
Cookie: "{{ login.cookies_string }}"
validate_certs: false
register: portConf
- name: Print portConf
debug:
msg: "{{ portConf }}"
SwitchConf prints (the relevant part, only):
"msg": {
"access_control_allow_credentials": "true",
"access_control_expose_headers": "Access-Control-Allow-Origin,Access-Control-Allow-Credentials",
"changed": false,
"connection": "close",
"content_type": "application/json;charset=UTF-8",
"cookies": {},
"cookies_string": "",
"date": "Wed, 20 Oct 2021 18:22:24 GMT",
"elapsed": 0,
"failed": false,
"json": {
"data": [
{
(...)
"port_overrides": [
{
"port_idx": 1,
"portconf_id": "A"
},
{
"port_idx": 2,
"portconf_id": "B"
},
{
"port_idx": 3,
"portconf_id": "B"
},
{
"port_idx": 5,
"portconf_id": "B"
},
{
"port_idx": 6,
"portconf_id": "B"
},
{
"port_idx": 7,
"portconf_id": "B"
},
(...)
],
(...)
}
]
},
"msg": "OK (unknown bytes)",
"redirected": false,
"status": 200,
"transfer_encoding": "chunked",
"url": "https://adm01.local:8443/api/s/default/stat/device/",
"vary": "accept-encoding,origin,accept-encoding",
"x_frame_options": "DENY"
}
}
So, the question is: how can Ansible be used to fetch the JSON datagram portConf->data->port_overrides and change the "portconf_id" to "X" with "port_idx"==2, so that post_overrides can be used to POST it back?

Answer 1

The dictionaries in YAML are immutable. You have to create a new one to change anything. Given the simplified data
portConf:
status: 200
json:
data:
- port_overrides:
- port_idx: 1
portconf_id: A
- port_idx: 2
portconf_id: B
- port_idx: 3
portconf_id: C
and the required changes
diff:
port_idx: 2
portconf_id: X
the task below makes the changes in json.data
- set_fact:
_json: "{{ {'data': [{'port_overrides': _port_change}]} }}"
vars:
_port_remove: "{{ portConf.json.data.0.port_overrides|
rejectattr('port_idx', 'eq', diff.port_idx)|
list }}"
_port_change: "{{ (_port_remove + [diff])|sort(attribute='port_idx') }}"
gives
_json:
data:
- port_overrides:
- port_idx: 1
portconf_id: A
- port_idx: 2
portconf_id: X
- port_idx: 3
portconf_id: C
and the next task combines the changes
- set_fact:
portConf: "{{ portConf|combine({'json': _json}) }}"
gives
portConf:
json:
data:
- port_overrides:
- port_idx: 1
portconf_id: A
- port_idx: 2
portconf_id: X
- port_idx: 3
portconf_id: C
status: 200