json dictionary ansible conditional-statements jinja2

How to search for a specific value in a multiple dictionary list, then extract another value from the same list?

After debugging results of a task, I want to be able to get the corresponding uuid just by entering a specific snapshot_name.

This is the output of the "result" variable:

ok: [localhost] => {
    "msg": {
        "date": "Mon, 22 May 2023 03:39:34 GMT",
        "elapsed": 0,
        "expires": "0",
        "failed": false,
        "json": {
            "entities": [
                {
                    "created_time": 1684493611741165,
                    "deleted": false,
                    "logical_timestamp": 1,
                    "snapshot_name": "Snapshot 1",
                    "uuid": "ffa972f7-25b7-4d0c-8e92-2e7afef863c4"
                },
                {
                    "created_time": 1684502215147173,
                    "deleted": false,
                    "logical_timestamp": 1,
                    "snapshot_name": "vm snapshot",
                    "uuid": "6f1kc72a-8916-4edd-9639-c2823b57a1cb"
                },
                {
                    "created_time": 1684725225721634,
                    "deleted": false,
                    "logical_timestamp": 1,
                    "snapshot_name": "new",
                    "uuid": "ad872bde-3a94-411f-8f89-5f5ad55e4ffa"
                }
            ],
            "metadata": {
                "grand_total_entities": 3,
                "total_entities": 3
            }
        },
        "msg": "OK (unknown bytes)",
        "pragma": "no-cache",
        "redirected": false,
        "server": "envoy"
    }
}

This is my playbook:

- name: debug
  debug:
    msg: "{{ result }}"

- name: Snapshot name to look for
  set_fact:
    snapname: "{{ snapname }}"

- name: Getting the uuid of the above snapname
  debug:
    msg: "{{ result.json.entities[*].uuid }}"
  when: result.json.entities[*].snapshot_name == snapname

Snapname is a variable as I want to be able to be able to enter different snapname values in ansible controller itself, so it is meant to be a changeable variable. Then let ansible search for the snapname value and get its corresponding uuid.

I got this error for the last task in my playbook:

fatal: [localhost]: FAILED! => {
    "msg": "The conditional check 'result.json.entities[*].snapshot_name == snapname' failed. The error was: template error while templating string: unexpected '*'. String: {% if result.json.entities[*].snapshot_name == snapname %} True {% else %} False {% endif %}\n\nThe error appears to be in '/var/lib/awx/projects/Nutanix/roles/vm_restore/tasks/vm_restore.yml': line 46, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: debug\n  ^ here\n"
}

How do I write my playbook in a way that when the value of snapname == "vm snapshot", it will search for "vm snapshot" in "snapshot_name" in all the lists, then get the corresponding uuid?

For example, search which list has "vm_snapshot", then output the uuid, "6f1kc72a-8916-4edd-9639-c2823b57a1cb".

Solution

You can use either json_query

     - debug:
         msg: "{{ result.json.entities|
                  json_query('[?snapshot_name == `vm snapshot`].uuid') }}"

, or selectattr and map

     - debug:
         msg: "{{ result.json.entities|
                  selectattr('snapshot_name', '==', 'vm snapshot')|
                  map(attribute='uuid') }}"

Both tasks give the same result

  msg:
  - 6f1kc72a-8916-4edd-9639-c2823b57a1cb

The code below shows how to substitute a variable

     - debug:
         msg: "{{ result.json.entities|json_query(_query) }}"
       vars:
         snapname: vm snapshot
         _query: '[?snapshot_name == `{{ snapname }}`].uuid'

     - debug:
         msg: "{{ result.json.entities|
                  selectattr('snapshot_name', '==', snapname)|
                  map(attribute='uuid') }}"
       vars:
         snapname: vm snapshot

But, if the values of snapshot_name are unique, you can create a dictionary first

  snapshot_uuid: "{{ result.json.entities|
                     items2dict(key_name='snapshot_name', value_name='uuid') }}"

gives

  snapshot_uuid:
    Snapshot 1: ffa972f7-25b7-4d0c-8e92-2e7afef863c4
    new: ad872bde-3a94-411f-8f89-5f5ad55e4ffa
    vm snapshot: 6f1kc72a-8916-4edd-9639-c2823b57a1cb

The search is trivial now.

^{Example of a complete playbook for testing
- hosts: all

vars:

result:
date: Mon, 22 May 2023 03:39:34 GMT
elapsed: 0
expires: '0'
failed: false
json:
entities:
- created_time: 1684493611741165
deleted: false
logical_timestamp: 1
snapshot_name: Snapshot 1
uuid: ffa972f7-25b7-4d0c-8e92-2e7afef863c4
- created_time: 1684502215147173
deleted: false
logical_timestamp: 1
snapshot_name: vm snapshot
uuid: 6f1kc72a-8916-4edd-9639-c2823b57a1cb
- created_time: 1684725225721634
deleted: false
logical_timestamp: 1
snapshot_name: new
uuid: ad872bde-3a94-411f-8f89-5f5ad55e4ffa
metadata:
grand_total_entities: 3
total_entities: 3
msg: OK (unknown bytes)
pragma: no-cache
redirected: false
server: envoy

snapshot_uuid: "{{ result.json.entities|
items2dict(key_name='snapshot_name', value_name='uuid') }}"

tasks:

- debug:
var: snapshot_uuid

- debug:
msg: "{{ result.json.entities|
selectattr('snapshot_name', '==', 'vm snapshot')|
map(attribute='uuid') }}"

- debug:
msg: "{{ result.json.entities|
json_query('[?snapshot_name == `vm snapshot`].uuid') }}"}