docker-py/docs/port-bindings.md

Port bindings

Port bindings is done in two parts. Firstly, by providing a list of ports to open inside the container in the Client().create_container() method. Bindings are declared in the host_config parameter.

container_id = cli.create_container(
    'busybox', 'ls', ports=[1111, 2222],
    host_config=cli.create_host_config(port_bindings={
        1111: 4567,
        2222: None
    })
)

You can limit the host address on which the port will be exposed like such:

cli.create_host_config(port_bindings={1111: ('127.0.0.1', 4567)})

Or without host port assignment:

cli.create_host_config(port_bindings={1111: ('127.0.0.1',)})

If you wish to use UDP instead of TCP (default), you need to declare ports as such in both the config and host config:

container_id = cli.create_container(
	'busybox', 'ls', ports=[(1111, 'udp'), 2222],
    host_config=cli.create_host_config(port_bindings={
        '1111/udp': 4567, 2222: None
    })
)

To bind multiple host ports to a single container port, use the following syntax:

cli.create_host_config(port_bindings={
    1111: [1234, 4567]
})

You can also bind multiple IPs to a single container port:

cli.create_host_config(port_bindings={
    1111: [
        ('192.168.0.100', 1234),
        ('192.168.0.101', 1234)
    ]
})