3 backend + 1 nginx
$ sudo docker-compose up --build
$ docker exec -it docker-nginx_backend1_1 /bin/bash
$ node index.js
$ docker exec -it docker-nginx_backend2_1 /bin/bash
$ node index.js
$ docker exec -it docker-nginx_backend3_1 /bin/bash
$ node index.js
$ curl http://localhost:8080
Will return hostname of the current backend server
You can open in browser http://localhost:8080 and see the hostname as well