How to create a second IP just for dockers
If you pass the listen address as the very first component of -p, Docker will only listen on that address:
$ docker run -p 127.0.1.2:8080:80 -d nginx`
$ ss -ltp | grep 127.0.1.2
LISTEN  0       4096         127.0.1.2:http-alt          0.0.0.0:*