Removing kernels from fleet

First and foremost

Don’t Panic

Issue the following command from the chef repo:

bundle exec knife ssh -a ipaddress 'roles:ROLE_HERE' "dpkg-query --show 'linux-*' | awk '/4\.13/ {print \$1}' | xargs -r sudo apt-get -yqq purge"

Notes:

escape the dot in kernel version for stricter match
escape $1 in awk so that remote bash doesn’t assume $1 is its first argument
be careful if you adapt this command to remove 4.11 kernels for some reason, as those are installed in these hacky recipes for azure and gcp respectively.

Issues:

This was deliberately not made into chef cookbook because packer is how we should do it.