nameko-injector 0.1.0

Injector support in nameko

[injector](https://pypi.org/project/injector/ “cool injector library”) based dependency injection mechanism for the nameko services. Project is similar to [flask-injector](https://pypi.org/project/Flask-Injector/).

Problem

Nameko provides dependency injection mechanism, built-in in the framework. It works in many cases but there are limitations:

1. All the dependencies are injected regardless whether they are used in the entrypoint. For instance, all the dependencies will be injected for /health HTTP entry point.

2. Dependencies cannot depend on each other.

3. Scope is an implementation detail. Frequency of the dependency creation depends on the DependencyProvider implementation.

Solution

The library provides an alternative dependency injection mechanism to the one that is bult in in nameko. There are several types of request scope that can be used out of the box without special injector modules declarations.

• nameko_injector.core.ServiceConfig

• from nameko.containers.ServiceContainer

• from nameko.containers.WorkerContext

An example:

import json
from nameko_injector.core import NamekoInjector, ServiceConfig
from nameko.web.handlers import http


INJECTOR = NamekoInjector()

@INJECTOR.decorate_service
class Service:

  name = 'service-name'

  @http('GET', '/health')
  def health(self, request):
     return {'status': 'ok'}

  @http('GET', '/config')
  def view_config(self, request, config: ServiceConfig):
    return json.dumps(config)

Development

tox

TODO

• testing: Add the tests for RPC entrypoints

• document testing with the library