events {}
http {
  upstream backend5000 { server server:5000; }
  upstream backend5001 { server server2:5001; }
  upstream backend5002 { server server3:5002; }

  server {
    listen 80;
    location /api1/ { proxy_pass http://backend5000/; }
    location /api2/ { proxy_pass http://backend5001/; }
    location /api3/ { proxy_pass http://backend5002/; }
  }
}