Websocket Server

A minimal Websockets Server in Python with no external dependencies.

Python3.6+
Clean simple API
Multiple clients
No dependencies

Notice that this implementation does not support the more advanced features like multithreading etc. The project is focused mainly on making it easy to run a websocket server for prototyping, testing or for making a GUI for your application.

Installation

Install with pip

pip install websocket-server

For coding details have a look at the server.py example and the API.

Usage

You can get a feel of how to use the websocket server by running

python server.py

Then just open client.html in your browser and you should be able to send and receive messages.

Testing

Run all tests

pytest

API

The API is simply methods and properties of the WebsocketServer class.

WebsocketServer

The WebsocketServer can be initialized with the below parameters.

port - The port clients will need to connect to.

host - By default the 127.0.0.1 is used which allows connections only from the current machine. If you wish to allow all network machines to connect, you need to pass 0.0.0.0 as hostname.

loglevel - logging level to print. By default WARNING is used. You can use logging.DEBUG or logging.INFO for more verbose output.

key - If using SSL, this is the path to the key.

cert - If using SSL, this is the path to the certificate.

Properties

Property	Description
clients	A list of `client`

Methods

Method	Description	Takes	Gives
`run_forever()`	Runs server until shutdown_gracefully or shutdown_abruptly are called.	threaded: run server on its own thread if True	None
`set_fn_new_client()`	Sets a callback function that will be called for every new `client` connecting to us	function	None
`set_fn_client_left()`	Sets a callback function that will be called for every `client` disconnecting from us	function	None
`set_fn_message_received()`	Sets a callback function that will be called when a `client` sends a message	function	None
`send_message()`	Sends a `message` to a specific `client`. The message is a simple string.	client, message	None
`send_message_to_all()`	Sends a `message` to all connected clients. The message is a simple string.	message	None
`shutdown_gracefully()`	Shutdown server by sending a websocket CLOSE handshake to all connected clients.	None	None
`shutdown_abruptly()`	Shutdown server without sending any websocket CLOSE handshake.	None	None

Callback functions

Set by	Description	Parameters
`set_fn_new_client()`	Called for every new `client` connecting to us	client, server
`set_fn_client_left()`	Called for every `client` disconnecting from us	client, server
`set_fn_message_received()`	Called when a `client` sends a `message`	client, server, message

The client passed to the callback is the client that left, sent the message, etc. The server might not have any use to use. However it is passed in case you want to send messages to clients.

Example:

import logging
from websocket_server import WebsocketServer

def new_client(client, server):
	server.send_message_to_all("Hey all, a new client has joined us")

server = WebsocketServer(host='127.0.0.1', port=13254, loglevel=logging.INFO)
server.set_fn_new_client(new_client)
server.run_forever()

Example (SSL):

import logging
from websocket_server import WebsocketServer

def new_client(client, server):
	server.send_message_to_all("Hey all, a new client has joined us")

server = WebsocketServer(host='127.0.0.1', port=13254, loglevel=logging.INFO, key="key.pem", cert="cert.pem")
server.set_fn_new_client(new_client)
server.run_forever()

Client

Client is just a dictionary passed along methods.

{
	'id'      : client_id,
	'handler' : client_handler,
	'address' : (addr, port)
}

savejeff/python-websocket-server