I know number of ways to remove old kernel versions manually. Is there any way to remove old kernel versions automatically? Automatically, in the sense i don't have to do the same thing each time the kernel gets updated.
You can follow the Using the "unattended-upgrades" package section of Automatic Security Updates article on Ubuntu Wiki to perform this.
You need to change the following line in /etc/apt/apt.conf.d/50unattended-upgrades file;
to automatically remove old packages, including kernels.
Also remove or comment the line
in the "NeverAutoRemove" section of the file /etc/apt/apt.conf.d/01autoremove.