So I've got a toke/mosquitto docker container running to which I can connect from outside docker.

Then I'm using a Python docker container that should publish data to my mosquitto broker. Here's my code:

```
import paho.mqtt.client as paho
import time
import random

broker = "localhost"
port = 1883

def on_publish(client, userdata, result):
    print("Device 1 : Data published.")
    pass

client = paho.Client("admin")
client.on_publish = on_publish
client.connect(broker, port)

for i in range(20):
    d = random.randint(1, 5)

    # telemetry to send
    message = "Device 1 : Data " + str(i)
    time.sleep(d)

    # publish message
    ret = client.publish("/data", message)

print("Stopped...")

```

The code works trying to connect to a mqtt broker not running in docker.

But I can't figure out how to let both run with docker and connect to each other. My error message is:

```
Traceback (most recent call last):
  File "./pub_client1.py", line 15, in <module>
    client.connect(broker, port)
  File "/usr/local/lib/python3.8/site-packages/paho/mqtt/client.py", line 937, in connect
    return self.reconnect()
  File "/usr/local/lib/python3.8/site-packages/paho/mqtt/client.py", line 1071, in reconnect
    sock = self._create_socket_connection()
  File "/usr/local/lib/python3.8/site-packages/paho/mqtt/client.py", line 3522, in _create_socket_connection
    return socket.create_connection(addr, source_address=source, timeout=self._keepalive)
  File "/usr/local/lib/python3.8/socket.py", line 808, in create_connection
    raise err
  File "/usr/local/lib/python3.8/socket.py", line 796, in create_connection
    sock.connect(sa)
OSError: [Errno 99] Cannot assign requested address

```

Im already using a docker network. What am I missing?

Thanks already for the help :)