Dynamically allocate available port. Just excersice - better use DockerContainer ability to do it itself

testcontainers_utils.py

import socket
from testcontainers.core.container import DockerContainer


class DynamicPortDockerContainer(DockerContainer):
    def bind_available_port(self, container_port: int) -> int:
        """Find an available port on the host machine and bind it to the `container_port`.

        Return bound host port number.
        """
        # todo: on container start if port was occupied retry?
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.bind(("", 0))  # Bind to an available port provided by the OS
        host_port = s.getsockname()[1]  # Retrieve the port number
        s.close()  # Close the socket

        # (!) does not reserve the port till container start
        self.with_bind_ports(container_port, host_port)

        return host_port