Unable to install mongodb properly on ubuntu 18.04 LTS

just want to chime in here. I'm the Senior Technical Writer for MongoDB Server Docs. This post is one of a few that comes up with "install MongoDB on Ubuntu 18.04", and there are several comments here referencing the mongodb package for installation. The unofficial mongodb package provided by Ubuntu is not maintained by MongoDB. You should always use the official MongoDB mongodb-org packages. Furthermore, from a bit of personal testing it looks like having mongodb installed will cause issues if you try to install mongodb-org, so its just added trouble

The few times I've run into this issue when testing locally, attempting to install one of the subpackages (i.e. mongodb-org-server) usually surfaced the actual error (i.e. missing libcurl3, which was removed in 18.04 as a default installed library). These issues may be more common when testing development builds ( at the time of writing, that's the 4.2 dev series).

To check which package you have installed on your local system, run the following:

sudo apt list --installed | grep mongo

This was my output after I installed mongodb, then attempted mongodb-org:

mongo-tools/bionic,now 3.6.3-0ubuntu1 amd64 [installed,auto-removable]
mongodb-org/bionic,now 4.0.5 amd64 [installed]
mongodb-org-shell/bionic,now 4.0.5 amd64 [installed,automatic]
mongodb-server-core/bionic,now 1:3.6.3-0ubuntu1 amd64 [installed,auto-removable]

So you can see, I've got a mix between the two packages (and a bunch of dkpg errors). I ended up using a mix of apt remove , apt autoremove, and apt purge to fix up the system.

You need to first uninstall the mongodb, you can use:

sudo apt-get purge mongodb-org*

After this, install mongodb through the following commands:

sudo apt-get install mongodb

And then update:

sudo apt-get update

You are done with the installation of mongodb. You can check it by using the below command:

mongo --version

Based on this excellent Answer: https://stackoverflow.com/a/51421152/659354

And this Page: https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/

The commands I used to install MongoDB 4.2

sudo apt-get purge mongo* - Note: mongo to remove the client as well as the server.

sudo apt-get install mongodb-org - Note: install command run after the Mongodb.org Source was added to the Apt-get sources list.

This is because as of now Mongo DB for Ubuntu 18.04 is only available as a development version (See: MongoDB Distros).

I just installed it by doing the following:

Add the corresponding signature:

    sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 4B7C549A058F8B6B  

Add the supported version:

echo "deb [arch=amd64] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/development multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list

Update:

    sudo apt update

Install:

sudo apt install mongodb-org-unstable

If you get a "GPG error" repeat step 1 with the key that is shown in the error message. You might be able to install via

sudo apt install mongodb

but according to MongoDB this is not supported and will most probably not install the newest version.