The latter is I think just a matter of overriding the entrypoint of the image which is easy to do in a system like docker compose (or changing the arguments that you pass to docker run). The former is a bit trickier and I don't think i've seen a request for it before - there are some general docker docs for it here though that aren't dagster specific: https://docs.docker.com/config/containers/multi-service_container/

@daniel For clarification, the GRPC server points at a local repo, but we want to modify code in that repo over the network, after the GRPC server has been started. How can we extend the GRPC server with additional endpoints? For example, we want to modify a config variable in a yaml file remotely. It would be nice to not have to create an additional server on the same machine.