Barrier (a software KVM switch)

Barrier is an incredible software that lets you use the same keyboard and mouse with different computers without the need for hardware. I have two computers on my desk, and I used to have a hardware KVM (keyboard, video, and mouse) switch, which became obsolete when my computers started to output their video via HDMI. Hence, I have two keyboards on my desk, which is not very ergonomic. I knew about software solutions to this dilemma, but I never had the time to implement them, and I also did not want to pay a subscription fee for this luxury. I now started to use Barrier: https://github.com/debauchee/barrier. It's been working excellently so far (except for the installation and documentation), but I still need to get it to work before logging in to dump my second keyboard.

here are the steps that were not well documented:

When installed on Ubuntu, Barrier does not automatically create certificates. So you need to do this yourself:

Execute in both client and server: /home/username/.local/share/barrier/SSL:
openssl req -x509 -nodes -days 365 -subj /CN=Barrier -newkey rsa:4096 -keyout Barrier.pem -out Barrier.pem

You also need to open port 24800 if you are using a firewall. After you get Barrier working, check the correct command (ps aux) from the command line. It is probably something like this:

/usr/bin/barrierc -f --no-tray --debug INFO --name computer-name [87.167.231.88]:24800start

Use the Startup applications in Ubuntu and paste the above command in. This means you cannot use Barrier to log in because it is loaded only after logging in. But that's as much as I managed to figure out so far. There is probably a way to make this work pre-login via systemd, but I did not have the time to figure out how.