Docker not hosting anything on the port it says it is, what's going on?
By default docker containers do not expose any ports to the world outside of the container. When you start a container, you need to add a port mapping similar to NAT so it can be reached form outside (docs).
When you run docker run you need to pass the port mappings via -p IP:host_port:container_port parameter, i.e. docker run -p 443:5000. Then connect to it via https://localhost (https is on port 443).