What is Thunder?

Introduction

Thunder is developed by Metrological (a Comcast company), and provides a way for STB operators to implement business-logic in a modular way using plugins, and a consistent way for applications to control and query those plugins. By using a plugin-based architecture, it is possible to build a device with only the specific features that are required for that particular device.

Tip

Do not confuse Thunder and WPEWebKit. Whilst both are maintained by the Metrological/WPE team, they are not related. WPEWebKit is a fork of the WebKit browser for embedded devices, and shares no code with Thunder

To communicate with plugins, Thunder provides multiple RPC mechanisms which can be chosen depending on which is more appropriate for the client app and the IPC channel. However, a plugin author will simply develop their plugin against an interface and the exact RPC mechanism can be chosen at runtime.

By itself, Thunder does not provide much user-facing functionality, and is expected that plugins are developed to add the required business functionality.

The original aim for Thunder was to provide a bridge between the web-based Javascript world and a native Set Top Box (STB) device. This would allow web apps to query information about the device and invoke device functionality as required.

Development

Thunder is maintained by a development team at Metrological and Comcast on GitHub. Development takes place in the open on feature branches before being merged to master. Tagged releases are then made from master on a semi-regular basis

Versioning

Mainline Thunder versions are released by Metrological and are versioned Rx (e.g. R2, R3, R4,...). There can be many minor versions in a major release train (e.g. R4.1, R4.2)

Each release is tagged in the git repository and a tagged release has been fully QA tested.

When working with Thunder, it is strongly recommended to take a tagged release. The master branch is the active development branch and may be broken in weird and wonderful ways. There is no guarantee of stability on master.

CI

Builds on Linux and Windows and unit test runs are performed automatically on all PRs using GitHub Actions.

License

Relationship with RDK-V

Thunder was developed as a standalone component for use by Metrological in their products before Comcast acquired Metrological. It was the incorporated into the RDK-V software stack by Comcast and released as part of RDK-V 4.

Thunder is still used on non-RDK platforms, and the core Thunder framework does not have any coupling to RDK-V. Metrological maintain their own repository of plugins for use on their platforms, and RDK host their own RDKServices repository which contains RDK-V specific Thunder plugins.

RDK-V is currently using a fork of the R2 branch with many changes backported from R3/R4.