Docker creates defaultServer from server template by default.

RUN command can be used to create a new server. After this setup, when the container is started, there will be two servers defaultServer and namedserver, created using RUN command.

FROM icr.io/appcafe/open-liberty:[version-you-need]

# Create new Liberty server (namedServer)
RUN server create "namedServer"

... any other config 

# Overwrite default CMD
CMD ["server", "run", "namedServer"]