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@xprilion
Last active April 19, 2024 12:11
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Python Websockets SSL with Lets Encrypt
## Python Websockets SSL with Lets Encrypt
This code uses the `python-websockets` library.
You'll need to generate the certificate and keyfile using Let's Encrypt.
After generating the files correctly, you need to make them accessible to the current user who runs the script, my way of doing this was to copy it to the home directory of the current user and change the owner to the current user, set the permissions of the files to 400.
To know more about this process, read the blog here - https://xprilion.com/python-websockets-ssl-with-lets-encrypt/
<html>
<head>
<title>WebSocket demo</title>
<style type="text/css">
body {
font-family: "Courier New", sans-serif;
text-align: center;
}
.buttons {
font-size: 4em;
display: flex;
justify-content: center;
}
.button, .value {
line-height: 1;
padding: 2rem;
margin: 2rem;
border: medium solid;
min-height: 1em;
min-width: 1em;
}
.button {
cursor: pointer;
user-select: none;
}
.minus {
color: red;
}
.plus {
color: green;
}
.value {
min-width: 2em;
}
.state {
font-size: 2em;
}
</style>
</head>
<body>
<div class="buttons">
<div class="minus button">-</div>
<div class="value">?</div>
<div class="plus button">+</div>
</div>
<div class="state">
<span class="users">?</span> online
</div>
<script>
var minus = document.querySelector('.minus'),
plus = document.querySelector('.plus'),
value = document.querySelector('.value'),
users = document.querySelector('.users'),
websocket = new WebSocket("wss://localhost:6789/");
minus.onclick = function (event) {
websocket.send(JSON.stringify({action: 'minus'}));
}
plus.onclick = function (event) {
websocket.send(JSON.stringify({action: 'plus'}));
}
websocket.onmessage = function (event) {
data = JSON.parse(event.data);
switch (data.type) {
case 'state':
value.textContent = data.value;
break;
case 'users':
users.textContent = (
data.count.toString() + " user" +
(data.count == 1 ? "" : "s"));
break;
default:
console.error(
"unsupported event", data);
}
};
</script>
</body>
</html
#!/usr/bin/env python
# WS server example that synchronizes state across clients
import asyncio
import json
import logging
import websockets
import ssl
logging.basicConfig()
ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
# Generate with Lets Encrypt, copied to this location, chown to current user and 400 permissions
ssl_cert = "/home/username/fullchain.pem"
ssl_key = "/home/username/privkey.pem"
ssl_context.load_cert_chain(ssl_cert, keyfile=ssl_key)
STATE = {"value": 0}
USERS = set()
def state_event():
return json.dumps({"type": "state", **STATE})
def users_event():
return json.dumps({"type": "users", "count": len(USERS)})
async def notify_state():
if USERS: # asyncio.wait doesn't accept an empty list
message = state_event()
await asyncio.wait([user.send(message) for user in USERS])
async def notify_users():
if USERS: # asyncio.wait doesn't accept an empty list
message = users_event()
await asyncio.wait([user.send(message) for user in USERS])
async def register(websocket):
USERS.add(websocket)
await notify_users()
async def unregister(websocket):
USERS.remove(websocket)
await notify_users()
async def counter(websocket, path):
# register(websocket) sends user_event() to websocket
await register(websocket)
try:
await websocket.send(state_event())
async for message in websocket:
data = json.loads(message)
if data["action"] == "minus":
STATE["value"] -= 1
await notify_state()
elif data["action"] == "plus":
STATE["value"] += 1
await notify_state()
else:
logging.error("unsupported event: {}", data)
finally:
await unregister(websocket)
start_server = websockets.serve(counter, "0.0.0.0", 6789, ssl=ssl_context)
asyncio.get_event_loop().run_until_complete(start_server)
asyncio.get_event_loop().run_forever()
@glennmichaelmejias
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how about if python is the client?

@xprilion
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I wonder if any special configuration is needed to use python as a client for a websocket, maybe you can generate one easily using any GPT tools? Do let me know if that doesn't work for you.

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