This is a course work assignment submission; it might be an interesting starting point for learning event-based network programming (YMMV). Appended here is a slightly modified readme returned as part of the assignment. Note that the code contains numerous bugs and deficiencies (as the time assigned for the assignment was 2 weeks).
The Space Trade Quest game is built on a P2P network where the game server essentially only serves as a hookup point for the clients. Originally there was supposed to be a network of servers working as a "cloud", giving clients the option to join any server in the cloud to connect. That feature was unfortunately not completed in time for the submission. Servers can be chained in the actual implementation but all topology information is unfortunately not yet propagated due to missing code/bugs. The original design had a dynamic super-node allocation scheme where different space areas had different super-nodes. Currently clients just take a super-node position if they don’t find two other nodes to serve as a super-node. There is no performance monitoring of super nodes and no super-node voting mechanisms present. Most error conditions such as dropping nodes are handled poorly - clients disconnecting will not remove the ship from view. Saving and recovering after closing the client connection is not implemented. Most of the protocol resend logic is using static timeouts and RTT is not calculated. The GUI is rather simple. Visible ships are shown around the player and movement is possible.
STQ uses a few non-standard python3 modules, namely twisted (python3-twisted),
pysdl2 (python3-sdl2), netifaces (python3-netifaces) and monotime
(python3-monotime). Make sure you have them installed with your
package-manager or pip (i.e. python3 -m pip install <package>).
The server is started with a specific port number as a parameter. This will be the port number the client connects to.
./server.py 1337
The client connect to the server using the server host address and port number. When running both server and client locally, "127.0.0.1" can be used.
./client.py 127.0.0.1 1337 MyHandle
When the client starts, it immediately connects to the server and displays the space view. The spaceship can be controlled with the arrow keys. Left, Right for turn and Up for throttle and Down for brake. Collision detection (or anything else really) isn’t implemented. Multiple clients can connect to the same server. If using multi-host configuration, be sure to not use the local host address "127.0.0.1" as a destination address for the client as it confuses the client address discovery (bug/implementation deficiency).