# Maps the Connection header for WebSocket proxying. Goes in /etc/nginx/conf.d/ so it
# lives in the http{} context (a `map` can't go inside a server/location block).
# When a request carries `Upgrade: websocket`, send `Connection: upgrade`; otherwise
# `Connection: close`. Used by the voip.activeblue.net vhost for the /ws media stream.
map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}