jorzel / opentable

Clean architecture python application sample, with domain layer protected

Overview

Open table app for training purposes.

The project implements Ports and Adapters architecture in DDD style, trying to keep domain layer agnostic of external dependencies (ORM/DB, External Services).

Inner layers should not have any knowledge about outer layers. Application core (domain + application), should provide orchestration of whole business process exploiting existing ports. There are two types of ports:

• primary port, that is an entry exposing application core to outside world. It is usually a fascade called by a primary adapter (e.g. REST API, CLI, etc.),
• secondary port, enables application core to communicate with external world (e.g. database, mail sender, etc). It is an interface that is implemented by a secondary adapter.

The crucial thing here is that our application core does not have any knowledge about infrastructure and API, it operates only on interfaces. If we need a database access, we should define a repository interface and injected it into our service. Or, if there is a need for notification sending, we should make a notification sender interface that can be implemented by SMS or Email sender adapter in the infrastructure layer. But inside the application core we know nothing about infrastructure implementations (thanks to it the application logic can be easily unit tested). And this is the main gain of using this architecture.

Install packages

>> pip install -r requirements.txt

Run nameko application

>> nameko run --config src/api/nameko/config.yml src.api.nameko

Run tests

>> pip install -r test_requirements.txt
>> pytest

opentable's Issues

Suggest to loosen the dependency on nameko

Hi, your project opentable(commit id: 726b99a) requires "nameko==2.13.0" in its dependency. After analyzing the source code, we found that the following versions of nameko can also be suitable, i.e., nameko 2.7.0, 2.8.0, 2.8.1, 2.8.2, 2.8.3, 2.8.4, 2.8.5, 2.9.0rc0, 2.9.0, 2.9.0-rc0, 2.9.1rc0, 2.9.1, 2.9.1-rc0, 2.10.0, 2.11.0, 2.12.0, 2.14.0, 2.14.1, since all functions that you directly (4 APIs: nameko.extensions.Entrypoint.decorator, nameko.events.EventDispatcher.init, nameko.extensions.Entrypoint.decorator, nameko.testing.services.worker_factory) or indirectly (propagate to 2 nameko's internal APIs and 4 outsider APIs) used from the package have not been changed in these versions, thus not affecting your usage.

Therefore, we believe that it is quite safe to loose your dependency on nameko from "nameko==2.13.0" to "nameko>=2.7.0,<=2.14.1". This will improve the applicability of opentable and reduce the possibility of any further dependency conflict with other projects.

May I pull a request to further loosen the dependency on nameko?

By the way, could you please tell us whether such an automatic tool for dependency analysis may be potentially helpful for maintaining dependencies easier during your development?