For my FastAPI app, I’m trying to get Pydantic to validate my model with nested models in my item_config_descriptor field, but it doesn’t work. I should say that item_config_descriptor is not actually stored in the DB, but it is needed in the request body. I have this code.

Code

import datetime
import uuid
import ormar
from pydantic import BaseModel

class Items(ormar.Model):
    """
    Registry of all items.
    """

    class Meta(BaseMeta):
        tablename: str = "items"

    item_id: uuid.UUID = ormar.UUID(
        primary_key=True, as_uuid=True, default=uuid.uuid4, uuid_format="string"
    )
    item_name: str = ormar.String(max_length=255, nullable=False)
    item_type: str = ormar.String(max_length=255, nullable=False)
    item_model: str = ormar.String(max_length=255, nullable=False)
    item_vendor: str = ormar.String(max_length=255, nullable=False)
    item_version: str = ormar.String(max_length=255, nullable=False)
    item,_config_descriptor: ItemConfig = ormar.JSON(
        nullable=True, pydantic_only=True
    )
    item_config_id: Optional[uuid.UUID] = ormar.UUID(
        uuid_format="string", nullable=True
    )
    item_create_time: datetime.datetime = ormar.DateTime(
        default=datetime.datetime.now
    )

class ItemConfig(BaseModel):
    """
    API schema for posting new Item Configurations.
    """

    address: str
    interfaces: dict[str, ItemConfigInterface]

class ItemConfigInterface(BaseModel):
    """
    API schema for posting new Item Configuration Interfaces.
    """

    name: str
    mac_address: str
    ip_address: str

POST that works as expected

If I send the following POST it works as expected.

{
  "Item_name": "Test",
  "Item_type": "DUR",
  "Item_model": "Unknown",
  "Item_vendor": "Unknown",
  "Item_version": "Unknown",
  "Item_config_descriptor": {
    "address": "blah",
    "interfaces": {
      "i1": {
        "name": "blah",
        "mac_address": "blah",
        "ip_address": "blah"
      },
      "i2": {
        "name": "blah",
        "mac_address": "blah",
        "ip_address": "blah"
      }
    }
  }
}

Item_config_descriptor is not being validated

If I make any change to my nested data, like change the key “interfaces” to “interfacesssss”, FastAPI still accepts my POST.

{
  "Item_name": "Test",
  "Item_type": "DUR",
  "Item_model": "Unknown",
  "Item_vendor": "Unknown",
  "Item_version": "Unknown",
  "Item_config_descriptor": {
    "address": "blah",
    "interfacessssss": {
      "i1": {
        "name": "blah",
        "mac_address": "blah",
        "ip_address": "blah"
      },
      "i2": {
        "name": "blah",
        "mac_address": "blah",
        "ip_address": "blah"
      }
    }
  }
}

How can I change it so that my nested model in item_config_descriptor is also validated?