Install MongoDB on Ubuntu 18.04 servers
Run the following series of commands to install latest MongoDB on Ubuntu 18.04 servers
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4
$ echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list
$ sudo apt-get update
$ sudo apt-get install -y mongodb-org
These will install MongoDB for you, once installed run the following command to start it
$ sudo service mongod start