port forwarding the docker code example
Example: docker run port forward
docker run -d -p 5801:5800 --name vnc1 myvnc
docker run -d -p 5802:5800 --name vnc2 myvnc
docker run -d -p 5801:5800 --name vnc1 myvnc
docker run -d -p 5802:5800 --name vnc2 myvnc