server {
    listen 80;
    server_name _;
    root /usr/share/nginx/html;
    index index.html;
    add_header X-Content-Type-Options nosniff always;
    add_header X-Frame-Options DENY always;
    # WS protocol upgrade; heartbeat every 20s keeps the tunnel live.
    location = /api/ws {
        proxy_pass http://server:8080;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $http_host;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_read_timeout 75s;
        proxy_send_timeout 10s;
        proxy_buffering off;
    }
    location /api/ {
        proxy_pass http://server:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Proto $scheme;
        client_max_body_size 4m;
    }
    location / { try_files $uri $uri/ /index.html; }
    location ~ /\. { deny all; }
}