Build the docker image and run it:
docker build -t wstest .
docker run -d --name wstest -p 80:80 wstest
Navigate to http://localhost/ and then view the container logs with:
docker logs -f wstest
You should find that when clicking on the ws://localhost/ws button everything works fine, but clicking on the ws://localhost/error button gives a 403 (forbidden) error from uvicorn becuase the route doesn't exist (although this is a somewhat misleading error).