.. image:: https://api.travis-ci.org/kashifrazzaqui/vyked.svg?branch=master :target: https://travis-ci.org/kashifrazzaqui/vyked
Vyked is an asyncio based python framework for service oriented architectures. It is tested and used in production successfully.
.. code-block:: bash
$ pip install vykedVyked uses jsonstreamer_, a fast streaming JSON parser for Python that generates SAX-like events using the yajl C library. To install yajl:
.. code-block:: bash
$ git clone git@github.com:lloyd/yajl.git
$ cd yajl
$ ./configure && make install.. _jsonstreamer: https://github.com/kashifrazzaqui/json-streamer
Service Registry ^^^^^^^^^^^^^^^^ When Vyked services start they register with the service registry by advertising their name, ip,port and the names of other Vyked services they might require to function. The registry then co-ordinates all Vyked services and even balances loads across multiple instances of each service.
Vyked uses redis for pub-sub and registry storage, you must start a redis instance before you start the vyked registry.
You must start the Vyked registry before any services, as such:
.. code-block:: bash
$ python -m vyked.registryor :
.. code-block:: python
from vyked import Registry
registry = Registry('127.0.0.1', 4500)
registry.start()Service ^^^^^^^ Vyked allows you to host WS(Websocket), HTTP and TCP services.
TCP Services
Vyked TCP services provide an RPC-like api by decorating typical class methods with decorators. There are two types of api's available,
The following basic examples illustrate these decorators for both Services and remote Clients.
Sample TCP service:
.. code-block:: python
from asyncio import sleep
from vyked import Host, TCPService, api, publish
class IdentityTCPService(TCPService):
def __init__(self, ip, port):
super(IdentityTCPService, self).__init__("IdentityService", 1, ip, port)
@api
def create(self, user_name, password):
result = yield from sleep(5) #long running task
if user_name is None:
raise Exception('username cannot be none')
return result
@publish
def password_changed(self, user_name):
""" calling this method from within your code will cause a 'password_changed' event to be published
to all subscribing services
"""
# @publish decorated methods must return a dict of values to be published
return locals() # easy way to return a dict containing all the params - in this case, user_name.Sample HTTP service:
Vyked uses aiohttp to setup HTTP server.
.. code-block:: python
from vyked import Host, HTTPService, get, post, Response, Request
class IdentityHTTPService(HTTPService):
def __init__(self, ip, port):
super(IdentityHTTPService, self).__init__("IdentityService", 1, ip, port)
@get(path='/users/{username}')
def get(self, request: Request):
username = request.match_info.get('username')
return Response(status=200, body=("Hello {}".format(username)).encode())
@post(path='/users/{username}')
def create(self, request: Request):
data = yield from request.json()
return Response(status=200, body=(json.dumps(data)).encode())Sample WS service:
Vyked uses aiohttp to setup Websocket server.
.. code-block:: python
from vyked import Host, WSService, ws
class ChatWSService(WSService):
def __init__(self, ip, port):
super(ChatWSService, self).__init__("ChatService", "1", ip, port)
self.msgs = []
@ws(path='/')
def chat(self, msg=None):
if 'updater' in msg.data:
messages = ""
for m in self.msgs:
messages += m + "<br>"
return messages
else:
self.msgs.append(msg.data)To start a service:
.. code-block:: python
if __name__ == '__main__':
http = IdentityHTTPService('0.0.0.0', 4501)
tcp = IdentityTCPService('0.0.0.0', 4502)
Host.registry_host = '127.0.0.1'
Host.registry_port = 4500
Host.pubsub_host = '127.0.0.1'
Host.pubsub_port = 6379
Host.name = 'Identity'
Host.attach_service(http)
Host.attach_service(tcp)
Host.run()Client ^^^^^^^ So far, the examples have only covered standalone services. But a service might interact with other services. To make such an interaction possible, vyked provides a TCP and HTTP client to interact with TCP and HTTP service respectively.
Sample TCP client for IdentityService we saw in the above example:
.. code-block:: python
from vyked import Host, TCPService, TCPServiceClient, api, publish, request, subscribe
import asyncio
class IdentityClient(TCPServiceClient):
def __init__(self):
super(IdentityClient, self).__init__("IdentityService", 1)
@request
def create(self, user_name, password):
return locals() #@request requires a dict containing params describing the request payload
@subscribe
def password_changed(self, user_name):
print("Password changed event received")
yield from asyncio.sleep(4) Sample HTTP Client:
.. code-block:: python
class Hello(HTTPServiceClient):
def __init__(self):
super(Hello, self).__init__('Hello', 1)
@get()
def person(self, name):
path = '/{}'.format(name)
params = {'key': 'value'}
headers = {'Content-Type': 'application/json'}
app_name = 'test'
return locals()View documentation at read-the-docs_
.. _read-the-docs: http://vyked.readthedocs.org/en/latest/
vyked is offered under the MIT license.
The latest developer version is available in a github repository: https://github.com/kashifrazzaqui/vyked