Simple TCP server/client integration example for pyngrok, full documentation found at https://pyngrok.readthedocs.io/en/latest/integrations.html

1_pyngrok_TCPExample_server.py

# HOST="1.tcp.ngrok.io" PORT=12345 python server.py

import os
import socket

from pyngrok import ngrok

host = os.environ.get("HOST")
port = int(os.environ.get("PORT"))

# Create a TCP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Bind a local socket to the port
server_address = ("", port)
sock.bind(server_address)
sock.listen(1)

# Open a ngrok tunnel to the socket
public_url = ngrok.connect(port, "tcp", options={"remote_addr": "{}:{}".format(host, port))
print("ngrok tunnel \"{}\" -> \"tcp://127.0.0.1:{}/\"".format(public_url, port))

while True:
    connection = None
    try:
        # Wait for a connection
        print("\nWaiting for a connection ...")
        connection, client_address = sock.accept()

        print("... connection established from {}".format(client_address))

        # Receive the message, send a response
        while True:
            data = connection.recv(1024)
            if data:
                print("Received: {}".format(data.decode("utf-8")))

                message = "pong"
                print("Sending: {}".format(message))
                connection.sendall(message.encode("utf-8"))
            else:
                break
    except KeyboardInterrupt:
        print(" Shutting down server.")

        if connection:
            connection.close()
        break

sock.close()

2_pyngrok_TCPExample_client.py

# HOST="1.tcp.ngrok.io" PORT=12345 python client.py

import os
import socket

host = os.environ.get("HOST")
port = int(os.environ.get("PORT"))

# Create a TCP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Connect to the server with the socket via our ngrok tunnel
server_address = (host, port)
sock.connect(server_address)
print("Connected to {}:{}".format(host, port))

# Send the message
message = "ping"
print("Sending: {}".format(message))
sock.sendall(message.encode("utf-8"))

# Await a response
data_received = 0
data_expected = len(message)

while data_received < data_expected:
    data = sock.recv(1024)
    data_received += len(data)
    print("Received: {}".format(data.decode("utf-8")))

sock.close()