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Apertis is a versatile open source distribution and associated infrastructure, originally tailored to automotive use cases, but which has grown to be a fit for a wide variety of electronic devices. While Apertis provides components both for deployment on target devices and to meet the needs of development workflows, these are clearly separated, with special care taken to ensure that components intended for deliverables are free from problematic licensing constraints.

Apertis is not just a Debian-derived GNU/Linux distribution. It comprises: code hosting; code review tools; package build and image generation services; and an automated testing infrastructure with the aim of providing a clean, reliable environment. This allows developers to go from source to deployable system images in the most dependable way, ready to be hosted on the cloud, programmed into a custom device or made available via over-the-air (OTA) updates.

While the typical embedded workflow only supports one product line at a time, Apertis focuses on a collaborative development, aiming to be the integration point for multiple different independent product lines, each with different goals and different schedules, but all able to share the same common core.

Apertis provides the tools to needed to maximize the commonalities that can be shared across different lines of development, whilst also providing the ability for each product to experiment and differentiate without impacting the shared core.

Collaborative development

Apertis is designed for a collaborative development model with the aim of sharing efforts across and between multiple independent participants. It offers workflows and tools to maximize the shared commonalities, this reduces costs and increases development speed. This contrasts with approaches where participants of each development team are independently working towards there own goals, duplicating effort to implement common features.

While other workflows only focus on one team at a time, Apertis' strength is its ability to support many independent teams concurrently. The development infrastructure of Apertis runs as a service to provide shared access to all those independent product teams:

  • By connecting the software packages and the infrastructure through a well-defined interface, their mutual independence is guaranteed: This means that there should be no case where including an updated package requires changes to the infrastructure and, vice-versa, infrastructural changes do not require existing packages to be updated, reducing the maintenance burden over the long term
  • Common infrastructure is provided to developers: As a result developers do not need to go through the long and subtly error-prone process of setting up their own full build environment.
  • Tests get run on supported hardware devices automatically: By having existing test infrastructure, development teams are saved the burden of setting up their own test lab from scratch, enabling them to be running tests automatically on their supported hardware devices and device variants quickly.
  • What is tested is what ends up deployed on production devices: Apertis is able to run component unit tests as part of the centralized compilation and packaging process with additional system testing performed on automatically generated product images.

On top of the shared core, each user has access to dedicated project areas for components that are not meant to be shared with other teams, both for experimentation and for product development.

Contributions to the shared Apertis components follow Open Source Software (OSS) best practices with its maintainer/contributor policies centered on code review and continuous integration.

Security driven

The Apertis approach is driven by the need to increase safety and security by deploying updated software in the hands of users in a timely and efficient way.

Apertis is primarily built upon the latest Debian Stable sources enabling Apertis to directly benefit from its long term quality management, steady flow of fixes, compatibility and maturity, as shared by Debian and by its many derived distributions. By closely tracking Debian and a few other key upstream components, Apertis benefits from their well-defined CVE processes to identify urgent issues that affect packages hosted in their repositories and quickly act on those. Urgent patches like those fixing exploitable CVEs are merged timely into Apertis and are immediately available for downstream products. A quarterly release cycle provides a way for product teams to get access to a stable stream of less urgent updates.

In order to protect Apertis systems from the exploitation of both known and unknown application flaws, by either external or internal threats, Apertis utilizes AppArmor for policy enforcement. This enables the system to restrict each applications access to only those resources that they are meant to be using, providing mitigation against many potential attack vectors.

The optional OSTree-based update mechanism provides an efficient and safe update facility for the base platform, such that updates can be deployed often with minimal costs. The guide and demonstration installation of hawkBit providing an example of how to implement fleet manangement.

hawkBit using OSTree static deltas for OTA update

Applications can be deployed and updated in application bundles (with a new Flatpak-based solution on the way) without re-deploying the whole platform, decoupling the release and update cycle of the base software from that of each application.

A goal of Apertis is to reduce the efforts required for long-term maintenance, in particular to enable quick and consistent response times for security issues in internet-enabled products. The package-centric solution and shared infrastructure offered by Apertis enable all the involved teams to maximize commonalities across products to ensure the safety of deployed products in a timely manner as part of an economically sustainable long term strategy.

Package-centric approach

With Apertis, developers can focus on developing the components that provide their unique experience and rely on the shared core components and infrastructure for everything else.

Apertis builds on the proven practice, used by Debian and many other major distributions, separating the compilation of individual components into binary packages from the composition of images destined for target devices. This package-centric approach is the key enabler at the center of all activities, tools and processes in Apertis. The selection and selective customization of these binary packages enables deployable images to be created quickly and efficiently for a variety of different products and product variants via automated processes.

Basic workflow from source to image

The Apertis infrastructure enables the resources for processes like compilation to be shared across all users, with changes to common components getting processed once and resulting binaries being shared with all. These resources are available to every team and since they are provided as a service they do not need to be duplicated for each developer. This ensures reproducibility, traceability and consistency during the whole product life cycle.

Key technologies

Apertis makes heavy use of many open source technologies to form a strong platform:

  • Debian packages provide a wide ecosystem of pre-packaged components, from a project with a long history of providing a reliable, robust operating system.
  • systemd for system and service management, as well providing many basic services.
  • AppArmor adding Mandatory Access Control, providing policy enforcement of applicaiton profiles.
  • OSTree and Flatpak for safe, efficient and modular deployments
  • D-Bus providing inter-process communications, enabling privilege separation between the various system services and applications.
  • Wayland-based compositor, providing a modern efficient display server.
  • GStreamer enabling multimedia playback