#Step 1:  Import the MongoDB public key
#In Ubuntu 18.*+, you may get invalid signatures. --recv value may need to be updated to EA312927. 
#See here for more details on the invalid signature issue: [https://stackoverflow.com/questions/34733340/mongodb-gpg-invalid-signatures][1]

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10

#Step 2: Generate a file with the MongoDB repository url
echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' | sudo tee /etc/apt/sources.list.d/mongodb.list

#Step 3: Refresh the local database with the packages
sudo apt-get update

#Step 4: Install the last stable MongoDB version and all the necessary packages on our system
sudo apt-get install mongodb-org

         #Or
# The unofficial mongodb package provided by Ubuntu is not maintained by MongoDB and conflict with MongoDB’s offically supported packages. Use the official MongoDB mongodb-org packages, which are kept up-to-date with the most recent major and minor MongoDB releases.
sudo apt-get install -y mongodb