An example server for the websocket component on ESP-IDF using lwip netconn. The example can be made with make and uploaded with make flash.
This repository may not be actively developed (I have since organized development). See this for the most up to date example, and this for the most updated component.
The most updated component, with documentation, can be found here.
Some configuration options for the Server can be found in menuconfig in: Component config ---> WebSocket Server