Flask Dependency injection

Try Dependency Injector. It has with Flask tutorial. Your container will look something like:

from dependency_injector import containers, providersfrom dependency_injector.ext import flaskfrom flask import Flaskfrom flask_bootstrap import Bootstrapfrom github import Githubfrom . import views, servicesclass ApplicationContainer(containers.DeclarativeContainer):    """Application container."""    app = flask.Application(Flask, __name__)    bootstrap = flask.Extension(Bootstrap)    config = providers.Configuration()    github_client = providers.Factory(        Github,        login_or_token=config.github.auth_token,        timeout=config.github.request_timeout,    )    search_service = providers.Factory(        services.SearchService,        github_client=github_client,    )    index_view = flask.View(        views.index,        search_service=search_service,        default_query=config.search.default_query,        default_limit=config.search.default_limit,    )

To run the app you need to:

from .containers import ApplicationContainerdef create_app():    """Create and return Flask application."""    container = ApplicationContainer()    container.config.from_yaml('config.yml')    container.config.github.auth_token.from_env('GITHUB_TOKEN')    app = container.app()    app.container = container    bootstrap = container.bootstrap()    bootstrap.init_app(app)    app.add_url_rule('/', view_func=container.index_view.as_view())    return app

And testing will look like:

from unittest import mockimport pytestfrom github import Githubfrom flask import url_forfrom .application import create_app@pytest.fixturedef app():    return create_app()def test_index(client, app):    github_client_mock = mock.Mock(spec=Github)    # Configure mock    with app.container.github_client.override(github_client_mock):        response = client.get(url_for('index'))    assert response.status_code == 200    # Do more asserts

I'm not sure what you're trying to achieve exactly, but don't code in python with a java mindset.

If you're trying to add the cosmos_client to the app and access it from somewhere else you might want to save it as a config attribute to the flask app ?