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  DATE : 2021.01.18
  TIME : 17:31
AUTHOR : norris@sdf.org
 TITLE : CHECKRESTART AND NEEDRESTART
 
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I saw a toot on mastodon today talking about the program
checkrestart. checkrestart, which is part of the debian-goodies
package, can check and see which processes need to be restarted
after an upgrade. So why is this cool, what does it do, and is it
worth installing?

Well, in general linux machines get a lot of updates, but don't
need to be rebooted very often. When the ratio of updates to
required reboots is high, as it is especially in the case of
debian sid, there are going to be times where services may still
use old libraries after doing a apt upgrade. Running checkrestart
as su will list what processes and services are still using old
versions of new files. It will also list the total number of
processes, the number of distinct programs and packages affected,
and if any of these contain systemd definitions or init scripts
that can be used to restart them.

Looking into checkrestart, and installing and running it, led me
to finding out about a package, that was inspired by checkrestart,
called needrestart. needrestart checks which daemons need to
be restarted after library upgrades. needrestart, in addition
to scanning processes, will scan containers, interpreter
based-daemons (Java, Perl, Python, Ruby), processor microcode
upgrades for Intel CPUs, and the kernel, for cases where outdated
libraries are being run, and even if there are any user sessions
where outdated binaries are being run.  The coolest part for me
though, is that needrestart is fully integrated with apt/dpkg and
will prompt you with a which services should be restarted dialog
after an apt upgrade.

Even though I have run debian sid on my daily driver for over
15 years, with a potential for available updates every 6 hours,
without either of these programs installed until today, I would
argue, that both of these are worth installing and using. With a
distro like sid, there are some best practices; and while neither
checkrestart or needrestart make this best practice list (like the
must have apt-listbugs, and apt-listchanges packeges), needrestart
(and checkrestart) both provide useful information (and the choice
to act on the provided information) that can help make your high
update to reboot ratio machine more secure. These are good things
to have.

--norris

(o\_!_/o)