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• Repo: https://github.com/opencontainers/runc/
• Runc is the reference implementation of an OCI runtime and is developed directly by the OCI group. This is the runtime used by Docker, Kubernetes and others. However, being written in Go, it is less suitable for embedded STB environments due to a relatively large footprint.
• Not officially supported in RDK

SDK

To allow the development of DAC apps, an application SDK has been developed.

NOTES:

• High-level overview of what/why the SDK is needed

STB

Information on the tools used to run containers on a STB

NOTES:

• Dobby
• OCIContainers Thunder Plugin
• ProcessContainers integration
• RDKShell/Packager

Cloud/Backend Infrastructure

NOTES:

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• ASMS and submission portal
• BundleGen

STB

DAC provides all the necessary tooling to run containerised applications using OCI containers on an RDK-V STB. The main component of this is Dobby, an embedded-focused OCI container manager. Dobby is used to start, stop and monitor containers running on a STB, using the crun runtime underneath to interface with the kernel and start the containers. Dobby is written in C++ and designed to have minimal footprint and performance impact. The OCIContainer Thunder plugin allows for interfacing with Dobby using a JSON-RPC interface, and Dobby can also be used to run other Thunder plugins in containers using the ProcessContainer backend.

For more information on Dobby, see the detailed documentation here: Dobby Documentation

As part of DAC, the RDKShell plugin has been extended to allow starting DAC apps using Dobby, creating a display and attaching it to the containerised app as necessary. RDKShell also integrates with the Packager plugin to provide a full-featured solution for downloading, installing and lifecycle management of DAC apps. For more documentation on the RDKShell and Packager integration see RDKShell and Packager - Downloading, Installing and Launching DACs. See the Getting Started section below for an example of using these components together.

Cloud/Backend Infrastructure

To support the STB components, backend/cloud infrastructure has been developed. These components allow operators to create application submission portals where developers can submit their applications and their corresponding metadata. These submitted applications can then be converted from an OCI image to an OCI bundle ready for use on an operators specific hardware.

The AppStore Metadata Service (ASMS) component provides APIs for both a developer and an STB to use to upload application metadata and search for previously uploaded applications. More documentation on ASMS can be found here: App Store Metadata Service (ASMS) Documentation

The BundleGen tool is a command-line tool that runs in the cloud to prepare containers for use on specific platforms. It uses template files created by an operator to ensure that the container is configured appropriately for the specific hardware requirements of an operators STB. This includes but is not limited to graphics libraries, sockets, IPC and network configuration. More detailed documentation for BundleGen can be found here: BundleGen Documentation

SDK

To develop DAC applications, an SDK has been developed that allows developers to write Bitbake recipes that compile their code and produce an OCI image. This OCI image can then be uploaded to an OCI registry where it can be converted and downloaded to a STB ready to be run by Dobby. The SDK is based on Yocto 3.1 Dunfell and does not require any RDK specific layers - instead it uses the standard Poky distribution and can run on a developer's workstation, independent of any other build systems. This decreases the amount of time it takes for a developer to build and test their application, reducing development time.

Apps build using the DAC SDK are also designed to be cross-platform, since the OCI image will contain all the necessary dependencies. Providing the platform supports the necessary DAC libraries such as Wayland, the application will run on that platform with no manual modifications.

As part of the SDK, a number of example application recipes are included such as a Wayland EGL and Qt application.

The SDK is currently in Alpha and is subject to change as development continues

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Getting Started for App Developers

Reference Image

NOTES:

• RPi image with Dobby, crun etc can be found here: RDK reference image
• Contains everything needed to run DAC applications

Installing and Running DAC Applications

NOTES:

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A reference image for the Raspberry Pi 3B is available for app developers that containers all the tooling necessary to install and run DAC applications. The image contains the Lightning-based RefApp, RDKServices, AAMP as well as the DAC STB components such as RDKShell, Packager, Dobby and crun.

The image uses the meta-cmf-video-reference-next layer (https://code.rdkcentral.com/r/plugins/gitiles/components/generic/rdk-oe/meta-cmf-video-reference-next), which is contains all the necessary recipes for building DAC on the Raspberry Pi.

For more instructions on how to build/install the image, see the documentation here: RDK reference image

Installing and Running DAC Applications

App Development and Publishing

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