Install Unifi 5.8.x on Ubuntu 18.04 LTS
First, we must import the keys used by the package management system.
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 06E85760C0A52C50
Then, we must create the list file.
echo "deb [ arch=amd64,arm64 ] http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list
echo 'deb http://www.ubnt.com/downloads/unifi/debian stable ubiquiti' | sudo tee /etc/apt/sources.list.d/100-ubnt-unifi.list
Update the local package database:
sudo apt-get update
Install MongoDB 3.4.x
sudo apt-get install mongodb-org
Install Unifi
sudo apt-get install unifi