AttributeError: 'Provide' object has no attribute (boto3)

[sshann]

Hello, I am trying to inject a service (DynamoDB) to a class, but I keep getting the error AttributeError: 'Provide' object has no attribute 'Table'. I checked previous issues, but can seem to figure out what I did wrong. Could someone help me out?

I have dependency-injector version 4.36.2 installed

I have the following code:

# ./dependency_injection_setup.py
import controller


class Container(containers.DeclarativeContainer):
    """Specify the services that can be injected"""
    config = providers.Configuration()

    session = providers.Resource(
        boto3.session.Session,
        aws_access_key_id=config.aws_access_key_id,
        aws_secret_access_key=config.aws_secret_access_key,
    )

    dynamo_db = providers.Resource(
        session.provided.resource.call(),
        service_name='dynamodb',
        endpoint_url=config.endpoint,
    )


def bootstrap() -> Container:
    """Initialize the injected services with default configuration"""
    container = Container()
    if os.getenv('AWS_SAM_LOCAL'):
        container.config.endpoint.from_env('LOCALSTACK_ENDPOINT')
    container.init_resources()
    container.wire(modules=[controller])
    return container

# ./api_gateway_handler.py (Entrypoint)
from dependency_injection_setup import bootstrap, Container
from controller.RecipesController import RecipesController


def lambda_handler(event: APIGatewayProxyEventV2, _: context_.Context) -> APIGatewayProxyResponseV2:
    bootstrap()
    RecipesController().post()

# ./controller/RecipesController.py (where I want to inject)
class RecipesController(Controller):
    TABLE_NAME: str = "Recipes"
    dynamo_db: ServiceResource

    @inject
    def __init__(self, dynamo_db_provider=Provide[Container.dynamo_db]):
        self.dynamo_db = dynamo_db_provider()

    def post(self) -> APIGatewayProxyResponseV2:
        recipe = { "foo" = "bar" }

        # exception takes place here
        self.dynamo_db.Table(self.TABLE_NAME).put_item(Item=recipe)
        return created(recipe)

I have an __init__.py file in the root and controller directory

If I explicitly pass the dependency when creating the controller, then it works alright:

def lambda_handler(event: APIGatewayProxyEventV2, _: context_.Context) -> APIGatewayProxyResponseV2:
    container = bootstrap()
    RecipesController(container.dynamo_db).post()

[ilsurih]

One option is define provider of the controller in Container itself:

class Container(containers.DeclarativeContainer):
    ...
    recipes_controller = providers.Singleton(RecipesController, dynamo_db)

and then let IoC controller inverse control over the container and obtain an instance:

    container = bootstrap()
    container.recipes_controller().post()

Also I don't call the provider and use argument as an instance itself in my code:

    @inject
    def __init__(self, dynamo_db=Provide[Container.dynamo_db]):
        self.dynamo_db = dynamo_db

Probably you meant to use Provider[] instead of Provide[]?

But related to your issue I think it might be related to wiring of your controller package - try to either wire module:

import controller.RecipesController as recipies_module
...
    container.wire(modules=[recipies_module])

or package:

import controller as controller_package
...
    container.wire(packages=[controller_package])

[sshann]

My apologies for the very late reply, I was unable to work on this side project during November.

I updated the Provide to Provider and the wiring to set as packages instead of modules and it now works without explicitly passing the dependence :tada: nice :partying_face:

About the Provide/Provider, if I recall correctly, I based my implementation on the Application example (single container)#Main module. Is it a typo in the example or does its usage differs from my implementation? If it does differ, could you clarify what is the difference for me?

[MattConflitti]

Is this the preferred way to use this library with lambda handlers? Is it not possible to instantiate the container globally and decorate the handler with @inject? Only major hurdle I am seeing is that I don't know how to wire it up with that setup.