In the few years I've been using Linux as my main system, specifically Fedora, I've always seen my hostname set to just "localhost", with the exception of when I connect to some networks and it becomes my IP. Today I experienced the following behavior which I'm having trouble understanding though.
I set up an Ubuntu installation on another partition of my laptop, setting a computer name / hostname during the Ubuntu install. When I rebooted back into Fedora though, Fedora had updated my hostname to the name I set in the Ubuntu install.
I always thought the hostname was configured and stored on the partition of the distro installation, and indeed the contents of /etc/hostname on Fedora still read "localhost.localdomain", but running the
hostname command shows the new hostname. Both installs share an efi boot partition, but are otherwise discrete. I'm wondering from where and why the Fedora install is reading the new hostname?