KerOS 6

Software Update and Package Management

Your device running KerOS supports two update methods:

Using APT (Advanced Package Tool), you can update or install individual software packages. This method only updates the required components and keeps your data intact.

More details about a full software update using APT below

Firmware reinstallation (via SWUpdate):

This method replaces the entire system image with a new firmware version. It is similar to reinstalling an operating system on a computer.

Using this method erases all user data and customizations.

Unless you specifically need to reinstall the full firmware, Kerlink strongly recommends using APT for regular updates and maintenance. See firmware reinstallation if you want to proceed.

Getting Started with APT

APT is the package manager used on KerOS to install, upgrade, and remove software packages. It works with:

For full details, see the official APT documentation.

Installing Packages

The official repository is already configured on your device.

Update the APT package list:

sudo apt update

Install a package:

sudo apt install <package_name>

Example with tcpdump:

sudo apt update && sudo apt install tcpdump

You can also search for package containing a string:

sudo apt search something

From a local package file

If you obtained a Debian package file (e.g. mypackage.deb), install it with:

sudo apt install ./mypackage.deb

From a third party repository

To install a new package from a third-party repository, please refer to the online APT documentation.

Upgrading Packages

Upgrade a single package

sudo apt update && sudo apt install --only-upgrade <package_name>

Upgrade the entire system

To synchronize all packages with the latest available versions:

sudo apt update && sudo apt dist-upgrade

Handling Configuration File Conflicts

When upgrading, if a package needs to update a configuration file you have modified, APT will ask what to do. You can predefine the behavior using dpkg options:

Example command for an automatic conflict resolution:

sudo apt-get -o Dpkg::Options::="--force-confdef" \
        -o Dpkg::Options::="--force-confold" \
        --assume-yes dist-upgrade

Automatic System Reboot after Package Installation

Certain package updates —particularly those involving the Linux kernel or low-level system libraries— require a system reboot to fully apply the changes. Our system includes a custom APT hook that automatically detects when a reboot is necessary.

The reboot mechanism ensures that critical updates —especially security patches— are properly activated, maintaining the system’s stability and compliance. The reboot will take place automatically.

Automatic Updates

By default on the firmware, automatic updates are deactivated and configuration files are not present.

To keep your system up-to-date without manual intervention, you can configure automatic updates with unattended-upgrades.

sudo apt install unattended-upgrades

Configuration files:

To avoid configuration files conflict, do not modify Keros default configuration, prefer overriding using local customization

Example configuration:

Unattended-Upgrade::Origins-Pattern {
  "origin=*";
}
Unattended-Upgrade::Remove-Unused-Dependencies "true";
Unattended-Upgrade::SyslogEnable "true";

To enable automatic upgrades, /etc/apt/apt.conf.d/20auto-upgrades must also include:

APT::Periodic::Update-Package-Lists "always";
APT::Periodic::Unattended-Upgrade "always";

Scheduling

APT automatically runs updates through systemd timers:

Check timers with:

sudo systemctl list-timers --all

Adjust scheduling:

sudo systemctl edit apt-daily.timer
sudo systemctl edit apt-daily-upgrade.timer

Repository Lifecycle

Kerlink provides two types of repositories:

Checking or changing your repository

Configured repositories can be found in:

/etc/apt/sources.list.d/keros-deb.list

Example (default stable):

deb https://deb.keros.wanesy.com/<machine> stable main

To switch to testing, edit this file and replace with:

deb https://deb.keros.wanesy.com/<machine> testing main

Best Practices