Suffering from obsessive updating syndrome? Are you making frequent trips to the App Center or terminal to apply updates? Do update notifications haunt you all day long? If your on a Debian-based system, unattended upgrades can help.[1]


Systems based on Debian systems such as Ubuntu and elementary OS can use the unattended-upgrades package to automate system updates with Aptitude. The package provides a Python script by the same name. This tutorial provides a quick run through to install and configure the package for those familiar with Linux, Debian, Aptitude, and the command-line. The tutorial uses elementary OS 5.1 as the reference system. My configuration choices were based off my preferences for a system I use as a general desktop workstation.

This won’t update Flatpak applications for you. To do this, see Automate Flatpak Updates With systemd.

  1. Install the unattended-upgrades package.

    sudo apt -y install unattended-upgrades
  2. Refine the update behavior in the configuration file /etc/apt/apt.conf.d/50unattended-upgrades.

    1. Apply updates from all repositories.

      The Unattended-Upgrade::Allowed-Origins block contains specific repositories from which to update automatically. Lines are commented with //. Only Ubuntu repositories are listed in this file and some of the repositories are commented out. Uncomment these to use them. The following example enables "Ubuntu:bionic-updates"; and "Ubuntu:bionic-backports" enabling Ubuntu updates and backports. The lines for security updates were already uncommented, so I left those as they were.

      Unattended-Upgrade::Allowed-Origins {
              // Extended Security Maintenance; doesn't necessarily exist for
              // every release and this system may not have it installed, but if
              // available, the policy for updates is such that unattended-upgrades
              // should also install from here by default.
      //      "Ubuntu:bionic-proposed";

      For my particular use case, I want to allow updates from all repositories I have configured. I could add these manually to the Allowed-Origins block, but that’s more work than I’d like to do. Instead, my configuration replaces the Allowed-Origins block with an Origins-Pattern block which allows any origin with the * wildcard. This is shown in the following snippet.

      Unattended-Upgrade::Origins-Pattern {
    2. Remove unused dependencies.

      I don’t want to keep old or unused dependencies around, so I uncommented the following lines and set them each to true. The included comments are fairly self-explanatory.

      // Remove unused automatically installed kernel-related packages
      // (kernel images, kernel headers and kernel version locked tools).
      Unattended-Upgrade::Remove-Unused-Kernel-Packages "true";
      // Do automatic removal of new unused dependencies after the upgrade
      // (equivalent to apt-get autoremove)
      Unattended-Upgrade::Remove-Unused-Dependencies "true";
    3. Automatically reboot after upgrades when required.

      I don’t think anyone appreciates their desktop suddenly rebooting immediately after it applies some updates. I rarely leave my computer on for more than a few hours at a time. However, I figured it’s good to make sure the computer reboots eventually if necessary. The configuration below will automatically reboot but it does this at two in the morning to remain unobtrusive. To further reduce the chance of unexpected interruptions I’ve disallowed the computer from rebooting so long as users are logged in.

      // Automatically reboot *WITHOUT CONFIRMATION*
      //  if the file /var/run/reboot-required is found after the upgrade
      Unattended-Upgrade::Automatic-Reboot "true";
      // If automatic reboot is enabled and needed, reboot at the specific
      // time instead of immediately
      //  Default: "now"
      Unattended-Upgrade::Automatic-Reboot-Time "02:00";
      // Automatically reboot even if users are logged in
      Unattended-Upgrade::Automatic-Reboot-WithUsers "false";
  3. Configure Aptitude’s schedule for unattended-upgrades and related functions.

    Aptitude has it’s own scheduling configuration activated by systemd timers, namely apt-daily.timer and apt-daily-upgrade.timer. Aptitude configuration resides under the /etc/apt directory. The unattended-upgrades script should be enabled here.

    The package update-notifier-common is installed on my elementary OS system, so I simply updated the existing configuration file /etc/apt/apt.conf.d/10periodic with the appropriate settings to enable unattended-upgrades. Alternatively, you might create a new file with a higher precedence such as /etc/apt/apt.conf.d/20auto-upgrades or /etc/apt/apt.conf and put the configuration there.

    The options shown below use numbers to indicate the frequency to apply the corresponding operation in days. Unattended-Upgrade is set to one so that the unattended-upgrades script is run every day. Similarly, Update-Package-Lists is set to one because the package lists should be updated from their repositories each day. If the package lists aren’t updated automatically then packages wont be upgraded because updates won’t be detected, so enabling this is important. In addition to setting these two variables, I also set AutocleanInterval to automatically clean out the package cache every week.

    APT::Periodic::AutocleanInterval "7";
    APT::Periodic::Unattended-Upgrade "1";
    APT::Periodic::Update-Package-Lists "1";

    These variables and more are described in detail in the script /usr/lib/apt/apt.systemd.daily.

  4. Test the behavior of unattended upgrades by running the script manually with the --dry-run and --debug flags.

    sudo unattended-upgrades --dry-run --debug
  5. Monitor unattended upgrades by perusing the log files in /var/log/unattended-upgrades/.

See Also


You should know everything you need to get started automating package updates on Debian systems.

1. Side-effects may include sudden, irreversible blue-screen of death, failure to boot, changes in behavior, obscure glitches, and an increase in log messages. Talk to your system administrator before using unattended upgrades, especially for production systems. Use as prescribed.