Disable “New release available” emails on Ubuntu

Monday, August 15th, 2016

We have our Ubuntu machines set up to mail us the output of cron jobs like so:

$ cat /etc/crontab 
SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=admin@example.com

# m h dom mon dow user    command

This is encrible useful, since cronjobs should never output anything unless something is wrong.

Unfortunately, this means we also get emails like this:

/etc/cron.weekly/update-notifier-common:
New release '16.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

You can fairly easily disable these by modifying the corresponding cronjob /etc/cron.weekly/update-notifier-common:

 #!/bin/sh
 
 set -e
 
 [ -x /usr/lib/ubuntu-release-upgrader/release-upgrade-motd ] || exit 0
 
 # Check to see whether there is a new version of Ubuntu available
-/usr/lib/ubuntu-release-upgrader/release-upgrade-motd
+/usr/lib/ubuntu-release-upgrader/release-upgrade-motd > /dev/null

Now you’ll no longer receive these emails. It’s also possible to remove the cronjob entirely, but then an upgrade is likely to put it back, and I have no idea if the cronjob has any other side effects besides emailing.

Update: Raf Czlonka emailed me with the following addendum:

I wanted to let you know that there’s still one place which makes you see the annoying prompt:

/etc/update-motd.d/91-release-upgrade

an easier way to get rid if the “issue” is simply to run this:

# sed -i 's/^Prompt.*/Prompt=never/' /etc/update-manager/release-upgrades

Thanks Raf!