Running this script results in the printing of a recommended "apt purge" command to remove unused kernels, in order to free up space on the boot partition. It does not modify anything, it only shows what the system has installed and what can be removed. Keywords: ubuntu boot partition full no space left

cleanup-boot.py

import os
import re

print('--------------')
active_kernel_version = os.popen('uname -r').read().strip().replace('-generic', '')
existing_kernels = os.popen('dpkg --list | egrep -i --color "ii  (linux-image|linux-headers|linux-modules)"').read().strip()
print(existing_kernels)
print('--------------')
existing_kernels = os.popen('dpkg --list | egrep -i --color "ii  (linux-image)"').read().strip()
kernel_versions = []
for match in re.finditer("linux-image-([0-9.-]+)-generic", existing_kernels, re.IGNORECASE | re.MULTILINE):
	kernel_version = match.group(1)
	kernel_versions.append(kernel_version)
kernel_versions = sorted(kernel_versions, reverse=False)
for index, kernel_version in enumerate(kernel_versions):
  print('{index}: {version}{current}'.format(index=index, version=kernel_version, current=' (active)' if kernel_version == active_kernel_version else ''))
print('--------------')
packages = []
for kernel_version in kernel_versions[:-1]:
  if kernel_version != active_kernel_version:
    packages.append('linux-image-{version}-generic linux-headers-{version} linux-modules-{version}-generic'.format(version=kernel_version))

if len(packages) > 0:
  command = 'sudo apt purge ' + ' '.join(packages)
  print('')
  print(command)
else:
  print('')
  print(' -> all seems to be ok, no purging recommended')
print('')
print('--------------')

"""
example output:
--------------
ii  linux-headers-5.4.0-70                5.4.0-70.78                       all          Header files related to Linux kernel version 5.4.0
ii  linux-headers-5.4.0-70-generic        5.4.0-70.78                       amd64        Linux kernel headers for version 5.4.0 on 64 bit x86 SMP
ii  linux-headers-5.4.0-72                5.4.0-72.80                       all          Header files related to Linux kernel version 5.4.0
ii  linux-headers-5.4.0-72-generic        5.4.0-72.80                       amd64        Linux kernel headers for version 5.4.0 on 64 bit x86 SMP
ii  linux-headers-generic                 5.4.0.72.75                       amd64        Generic Linux kernel headers
ii  linux-image-5.4.0-70-generic          5.4.0-70.78                       amd64        Signed kernel image generic
ii  linux-image-5.4.0-72-generic          5.4.0-72.80                       amd64        Signed kernel image generic
ii  linux-image-generic                   5.4.0.72.75                       amd64        Generic Linux kernel image
ii  linux-modules-5.4.0-70-generic        5.4.0-70.78                       amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii  linux-modules-5.4.0-72-generic        5.4.0-72.80                       amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii  linux-modules-extra-5.4.0-70-generic  5.4.0-70.78                       amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii  linux-modules-extra-5.4.0-72-generic  5.4.0-72.80                       amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
--------------
0: 5.4.0-70
1: 5.4.0-72 (active)
--------------

sudo apt purge linux-image-5.4.0-70-generic linux-headers-5.4.0-70 linux-modules-5.4.0-70-generic

--------------
"""

Warning! While upgrading Kernels today I noticed that the ordering can be erroneous, see

0: 5.4.0-100
1: 5.4.0-96
2: 5.4.0-97
3: 5.4.0-99 (active)
--------------

sudo apt purge linux-image-5.4.0-100-generic linux-headers-5.4.0-100 linux-modules-5.4.0-100-generic linux-image-5.4.0-96-generic linux-headers-5.4.0-96 linux-modules-5.4.0-96-generic linux-image-5.4.0-97-generic linux-headers-5.4.0-97 linux-modules-5.4.0-97-generic

Where it recommends to delete 5.4.0-100 which is simply wrong.

Will fix this gist when I find some time to do it.