This is an extension that provides a server version of a WebSockets API for transmitting robot hardware interface state over a network. See the Robot Hardware Interface WebSockets API specification for more details on the protocol.
The WebSockets server has a number of configuration options available through environment variables.
HALSIMWS_SYSROOT: The local directory to serve non-websocket HTTP content from (e.g. HTML files) starting from /. Defaults to the sim subdirectory of the current working directory.
HALSIMWS_USERROOT: The local directory to serve non-websocket HTTP content from (e.g. HTML files) starting from /user/. Defaults to the sim/user subdirectory of the current working directory.
HALSIMWS_PORT: The port number to listen at. Defaults to 3300.
HALSIMWS_URI: The URI path to use for WebSockets connections. Defaults to "/wpilibws".