Falcon dynamic service creation

falcon_wrapper.py

# -* coding: utf-8 *-
import json
import traceback

import falcon


class Resource(object):

    def __init__(self):
        self._set_method_manager()

    def __retrieve_setting(self, name):
        return self.SERVICE_CONFIG.get(name)

    def get_url(self):
        url = self.__retrieve_setting('url')
        if not url:
            raise NotImplementedError()
        else:
            return url

    def _set_method_manager(self):
        method = self.__retrieve_setting('method').lower()

        print (method, str(self.__class__))

        if not method:
            raise NotImplementedError(
                'method config name is mandatory in SERVICE_CONFIG'
            )
        else:
            if method not in ['get', 'post']:
                raise ValueError('Method {} forbidden in this version'.format(
                    method
                ))

            def wrapper_method(req, res):
                try:
                    print req.method, str(self.__class__)
                    getattr(instance, 'process')(req, res)
                except Exception, e:
                    print 'Error: {}'.format(e)
                    traceback.format_exc().splitlines()
                    res.status = falcon.HTTP_500
                    req.context['result'] = {'status': 'Internal error'}

            method_name = 'on_{}'.format(method)
            setattr(self, method_name, wrapper_method)


class ServiceA(Resource):

    SERVICE_CONFIG = {
        'url': '/post_service',
        'method': 'POST'
    }

    def process(self, req, res):

        res.status = falcon.HTTP_200
        res.body = json.dumps({
            'message': 'POST service running!',
            'post_data': req.context['data']
        })


class ServiceB(Resource):

    SERVICE_CONFIG = {
        'url': '/get_service',
        'method': 'GET'
    }

    def process(self, req, res):
        res.status = falcon.HTTP_200
        res.body = json.dumps(
            {'message': 'GET service running!',
             'get_params': req.params}
        )


api = falcon.API()
services = [ServiceA, ServiceB]

for service in services:
    instance = service()
    api.add_route(instance.get_url(), instance)