Parent group is required attribute on contact group object when using REST API

[rodvand]

NetBox version

v3.1.0

Python version

3.8

Steps to Reproduce

curl -X POST \
-H "Authorization: Token TOKEN" \
-H "Content-Type: application/json" \
-H "Accept: application/json; indent=4" \
https://NETBOX_URL/api/tenancy/contact-groups/ \
--data '{
    "name": "Test Contact Group",
    "slug": "contact-group-slug" }'

Expected Behavior

A contact group is created.

Observed Behavior

{
    "parent": [
        "This field is required."
    ]
}

I reported a similar issue when creating a Contact object - #7771

In the API docs the parent is required, but nullable. I guess it is automatically set to null when using the Web UI. It would be handy if it defaults to null using the API to avoid having to explicitly set it to null when making requests.

[rodvand]

I also noticed that neither the name or slug is required to be unique. I am not sure if this is intentional, but I could see it lead to confusion when it's impossible to separate two (or more) groups with the same name.

[jeremystretch]

The serializer thinks the field is required because the parent field is referenced for unique enforcement. We've run into this with a number of other models as well. It might be something worth calling out upstream in DRF, but for now setting a default null value for the parent field on the serializer resolves this.

I also noticed that neither the name or slug is required to be unique.

Contact group names are required to be unique only within a parent group.