events {}

http {
    # Docker's built-in DNS. With the upstreams below held in variables,
    # nginx re-resolves the service names at request time instead of caching
    # the address from startup — so a recreated container (new IP) does not
    # leave nginx proxying to a stale address (502).
    resolver 127.0.0.11 valid=10s ipv6=off;

    # "Connection: upgrade" only for real upgrade requests, not every one.
    map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
    }

    server {
        listen 80;
        server_name _;

        # Api Requests
        location /api/ {
            set $api_upstream http://backend:5000;
            proxy_pass $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 $connection_upgrade;
        }

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

    }
}