LAN installation with an Ubuntu server

Solution 1:

If I understand the question, you would like to install on ComputerA while the installation UI is displayed on ComputerB.

One possible solution that might fit your requirements in the Ubuntu live-server (subiquity) installer. When this installer is run it creates an installer user that can be used to ssh into the installation.

In your scenario

1. Boot the installer on ComputerA.
2. From ComputerB, ssh into ComputerA as the installer user and be presented with the installation TUI.

The catch is that the installer user's password is randomly generated by default. You would need to use a custom autoinstall user-data file to set the password to something known or add an ssh key.

If you are looking for a solution that provides settings to a number of installations then you will likely want to learn about autoinstall anyway.

I can't vouch for how well the installation TUI works over ssh as I've never used this approach myself.