You can have many ways to install mongodb on linux. But I prefer to install the release from official resource.

Here are my steps to install mongodb 4.0 on ubuntu 18.04 system.

 $ curl -fsSL https://www.mongodb.org/static/pgp/server-4.0.asc | sudo apt-key add -
   
 $ 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 update
   
 $ sudo apt install mongodb-org

Please note:

  • From my test, ubuntu 18.04 doesn't support the latest mongodb 4.4 version, while 4.0 is supported.
  • mongodb 4.0 doesn't have arm64 architecture, only amd64 available.
  • After installation, mongodb doesn't start up by default, you need to start it by hand.

To start mongodb and enable it as a system service:

 $ sudo systemctl start mongod
 $ sudo systemctl enable mongod

You will see this port listening on the system:

 tcp        0      0 127.0.0.1:27017         0.0.0.0:*               LISTEN      12953/mongod

Now, let's login into mongodb and issue a query command:

 $ mongo
 MongoDB shell version v4.0.28
 ...
 ---
   
 > show databases
 admin   0.000GB
 config  0.000GB
 local   0.000GB
    
 > use admin
 switched to db admin
   
 > show tables
 system.version

All done.