Connecting to redis through dash-extensions Websocket - redis

Question

Is there a way to listen to redis publisher message, through Websocket of dash-extensions package?
from dash_extensions import WebSocket
...
html.Div(id="message", className='p-4 border'),
WebSocket(url='ws://127.0.0.1:6379/1', id='ws')
This gives error in redis-server
# Possible SECURITY ATTACK detected. It looks like somebody is sending POST or Host: commands to Redis. This is likely due to an attacker attempting to use Cross Protocol Scripting to compromise your Redis instance. Connection aborted.
Is such provision limited to specified redis clients only?

Answer 1

I believe that you are missing a component that reads the appropriate data from the Redis server and passes them through the websocket. This could be done in many different ways. Here is a small self-contained example written purely in Python,
import redis
import dash_html_components as html
from gevent import sleep
from dash import Dash
from dash.dependencies import Input, Output
from dash_extensions import WebSocket
from dash_extensions.websockets import SocketPool, run_server
# Read data from Redis and pass it through the web socket.
def ws_handler(ws):
while True:
sleep(2) # delay between updates, here 1s
value = redis.Redis().get('foo').decode("utf-8") # get redis value
ws.send(f"Redis value is [{value}]") # send data
# Inject some dummy data into Redis.
redis.Redis().set('foo', 'bar')
# Create example app.
app = Dash(prevent_initial_callbacks=True)
socket_pool = SocketPool(app, handler=ws_handler)
app.layout = html.Div([html.Div("Listening for message", id="log"), WebSocket(id="ws")])
#app.callback(Output("log", "children"), [Input("ws", "message")])
def update_graph(msg):
return msg['data']
if __name__ == '__main__':
run_server(app, port=5000) # 5000 if the default port