Changing hostname on Ubuntu 18.04 Server

Coming from previous versions of Ubuntu, I’m getting some issues with the new configuration system on Ubuntu 18.04. Not sure if some of them are welcomed (to me) but… they are there so we have no option.

Few moments ago, I’ve installed a new server with Ubuntu 18 and, thinking in future, I’ve created a blueprint on VMWare I could reuse for new servers. So I’ve create a new server with basic funcionalities, upgrade it and then convert to blueprint. Obviously, I gave it a nonsense name as ubuntu18

After that, I created a virtual machine from blueprint and, you guess it, I tried to change the name.

On previous versiones, I just needed to change it on /etc/hosts and /etc/hostname . That’s all. But now we need an aditional step. You need to change on /etc/cloud/cloud.cfg and tell you don’t want to upgrade the hostname (I could find where it finds the original name) on every reboot. The parameter is preserve_hostname and you need to change the default false value to true

So all steps:

• Edit /etc/cloud/cloud.cfg and change preserve_hostname: false to preserve_hostname: true
• Edit /etc/hostname and /etc/hosts . On hostname file, just put your new name. On /etc/hosts, add a line like 127.0.1.1 myHostName and x.x.x.x myHostName where x.x.x.x it’s your real IP name (if static)

That’s all!