How to assign static public IP to a docker container

Question

Is there any way to assign a static public IP to the container? So the container has the public IP. Clients can then access the container with that public static IP.

Answer 1

With currently released versions of Docker this isn't possible (without a lot of manual work behind Docker's back), although it is seldom necessary.

Docker exposes network services in containers through the use of port mappings, and port mappings can bind to specific ip addresses on your host. So if you want to have one web server at 192.168.10.10 and another webserver at 192.168.10.20, first make sure this addresses are available on your host:

ip addr add 192.168.10.10/24 dev eth0
ip addr add 192.168.10.20/24 dev eth0

Then start the first container:

docker run -p 192.168.10.10:80:80 mywebserver

And finally start the second container:

docker run -p 192.168.10.20:80:80 mywebserver

In the above commands, the -p option is used to bind the port mapping to a particular ip address. Now you have two containers offering a service on the same port (port 80) but on different ip addresses.