I may be late to this party, but I found this recently : Synergy

To use it on ubuntu or any other Linux distro, try this : QuickSynergy

Git for this project,  is here : Github

Synergy works on TCP/IP so you don’t need special hardware. By running server and client on both computers, you can share mouse and keyboard with multiple computers.

It works on multiple OSes and I’ve tried it across multiple ubuntu machines and between MacOS and ubuntu.

Computer with keyboard and mouse is the server or host. On linux, run the server as

$ synergys

From the client, run command

$ synergyc <Server Hostname Or IP>