What is on the other end(s) of this virtual serial connection? Do you want the container to connect a getty
process to it? Or will it be accessible as device to some other software running inside the container? Do you need help with that part?
Do you want to connect the other end to a physical serial device on the host? Or is this supposed to be a virtual device that allows you to talk to container from host?
Lots of different ways of interpreting your question.