MongoDB can be found in the Ubuntu software repositories, but as updates are frequent and the repository versions tend to lag behind, it's highly recommended to install it from the official Mongo package directly.
We'll go through how to do this step by step here, but as the installation procedures may change, it's advisable to get an updated version of the required URLs and steps from the official installation guide available at https://docs.mongodb.org/manual/tutorial/install-mongodb-on-ubuntu/.
The first thing we need to do is import MongoDB's public key so that the installation can be authenticated. On your VPS only (as before, we will not install a database server on our development machine), run the following:
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv EA312927
Now that we have the key, we can use the following command to add a link to the MongoDB package to our software sources. Note that this command is specific to Ubuntu 14.04 "Trusty", which...