This is a school assignment.
export PORT=8080
export MGO_URL=mongodb://<user>:<pass>@<host>/<db>
export MGO_TEST_URL=mongodb://<user>:<pass>@<host>/<db>
run commandands and/or add it to ~/.bashrc
PORT is the port the server is run on, you can change it to whatever you like.
MGO_URL is the mongodb URL to you main db.
MGO_TEST_URL is the mongodb URL to the a test db, used in test files.