events {}

http {
    # Docker's embedded DNS: resolve service names per request (cached 10s).
    # nginx would otherwise resolve them once at startup and keep proxying to
    # a recreated container's old IP — a 502 until nginx itself is reloaded.
    resolver 127.0.0.11 valid=10s ipv6=off;

    server {
        listen 80;
        server_name _;

        # Api Requests ("/api" without a trailing slash must land here too,
        # or it falls through to the frontend and loops through its SSR proxy)
        location /api {
            set $api_upstream backend:5000;
            proxy_pass http://$api_upstream;

            proxy_http_version 1.1;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }

        # Normal requests
        location / {
            set $frontend_upstream frontend:3000;
            proxy_pass http://$frontend_upstream;

            proxy_http_version 1.1;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }

    }
}