system-pri/frontend/nginx.conf

upstream web_app {
    server backend_service:5000;
}

server {
    listen 80;

    location / {
        root /usr/share/nginx/html;
        index index.html index.htm;
        try_files $uri $uri/ /index.html =404;
    }

    location ~ /api/ {
        proxy_pass http://web_app;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        proxy_redirect off;
    }
}