Replace epoll-server.c with an example at https://banu.com/blog/2/how-to-use-epoll-a-complete-example-in-c/
Modify epoll-server.c to echo back.
Add epoll-dummy-http-server.lua, but it fails with siege -r 10 -c 10.
I don't know why epoll_wait returns fd=0 or fd=1.