This is a text-only version of the following page on https://raymii.org:

This is a text-only version of the following page on https://raymii.org:
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Title : Silent unatended apt-get upgrade
Author : Remy van Elst
Date : 30-03-2013
URL : https://raymii.org/s/tutorials/Silent-automatic-apt-get-upgrade.html
Format : Markdown/HTML
---

This tutorial will show you how to setup completely silent apt-get upgrade via
cron. It also defaults to not overwriting config files if a package has a newer
version.

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> Important! You should watch out with this. Upgrades can break things. Use this
on your own risk.

apt-get can be ran from a cronjob with different options to let it update
everything without asking questions. However, the regular combination as seen
below still mails output (and thus, not upgrades) when a changed file is found
in a package, for example, the _/etc/lighttpd/lighttpd.conf_ file.

This is example output of such a situation:

apt-get upgrade -y --force-yes -qq

Configuration file `/etc/lighttpd/lighttpd.conf'
==> Modified (by you or by a script) since installation.
==> Package distributor has shipped an updated version.
What would you like to do about it ? Your options are:
Y or I : install the package maintainer's version
N or O : keep your currently-installed version
D : show the differences between the versions
Z : background this process to examine the situation
The default action is to keep your current version.
*** lighttpd.conf (Y/I/N/O/D/Z) [default=N] ?

The apt-get command is ran from cron, and the below lines are mailed.

#### The solution

Using a few options for DPKG results in this command:

DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get -q -y -o "Dpkg::Options::=--force-confdef" -o "Dpkg::Options::=--force-confold" upgrade

Results in this cronjob:

1 1 * * * DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical sudo apt-get -q -y -o "Dpkg::Options::=--force-confdef" -o "Dpkg::Options::=--force-confold" dist-upgrade

And if you also want to update the apt-cache:

1 3 * * * DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical sudo apt-get -q -y -o "Dpkg::Options::=--force-confdef" -o "Dpkg::Options::=--force-confold" dist-upgrade
1 1 * * * apt-get -y update

[1]: https://www.digitalocean.com/?refcode=7435ae6b8212

---

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