server {
    listen 80;
    server_name _;

    # Docker's embedded DNS (127.0.0.11). Without this, nginx resolves
    # upstreams once at startup and breaks the moment a peer container is
    # recreated with a new bridge IP. The `valid=10s` plus a variable in
    # proxy_pass forces per-request re-resolution.
    resolver 127.0.0.11 valid=10s ipv6=off;

    # Serve the Janus demo HTML/JS extracted from the canyan image.
    root /usr/share/nginx/html;
    index index.html;

    # Janus HTTP API — same origin as the demo pages so the default
    # settings.js URL ("http://<host>:8088/janus") just works. Regex so
    # /janus and /janus/<session>/... proxy, but /janus.js still hits
    # the static file root.
    location ~ ^/janus(/|$) {
        # Variable upstream + the resolver above = re-DNS on each request.
        # Plain `proxy_pass http://sip-web-janus:8088` would cache the IP
        # for the lifetime of the worker process.
        set $janus_upstream sip-web-janus;
        proxy_pass http://$janus_upstream:8088;
        proxy_http_version 1.1;
        proxy_buffering off;
        proxy_read_timeout 120s;
    }

    location / {
        try_files $uri $uri/ =404;
    }
}