Installing Unifi Controller in Fedora 33 is easy. Step one: install MongoDB from the official site since it is no longer available in Fedora due to licensing reasons. Use EL8 version which appears to work fine:

# dnf install ./mongodb-org-server-4.4.4-1.el8.x86_64.rpm

If you haven’t enabled RPMFusion repository, do it:

# dnf install$(rpm -E %fedora).noarch.rpm$(rpm -E %fedora).noarch.rpm

Install the controller:

# dnf install unifi

For some reason, unifi has hardcoded path to java alternatives symlink which did not work on the initial start (/usr/lib/jvm/jre-1.8.0/bin/java), reinstalling Java did help:

# dnf reinstall java-1.8.0-openjdk-headless

And enable the service:

# systemctl enable --now unifi

Beware, mongo service does not need to be started, unifi service spawns it’s own process:

# systemctl disable --now mongod

You’re done! Visit https://nuc.home.lan:8443 to manage your site.