Summary of prior internal discussion:

• A plugin/add-on would be just a file or folder that gets put in a particular place
  • i.e. include a file with an extension without having to create a whole docker container
    • this is valuable for making it easier to get started quickly with things, making small contributions / additions, as well as reducing unnecessary resource usage
  • useful for things like
    • Cockpit widgets / views / joystick configurations
    • documentation (e.g. for core: frontend: ardupilot-manager: link to firmware docs #1646)
    • themes (e.g. for core: frontend: add theme/style configuration interface #1938)
    • 3d models (e.g. for Allow 3d Model overrides #1440)
    • shared data (e.g. for support offline map data that can be shared by extensions #1820 and core: frontend: multi-language support #1937)
    • ArduPilot lua scripts (relevant to core: frontend: vehicle-setup: add page for Lua scripts #2372)
• Registered to a parent docker image, which can be either core or an installed extension
  • For extensions, stored in the persistent directory available for the extension (per File system: explicitly support extensions #1640)
  • We could locally keep track of installed sub-extensions using a json file or sqlite database, recording their versions, locations, and compatibility requirements
    • Alternatively they could provide their own metadata files
• Can be provided by the original developer or by the community
  • Installation would need to provide a differentiation, for "official" vs "community" add-ons
• How does one get one?
  • Available on Bazaar via the extensions manager, like a regular extension
  • Can be bundled together with an extension
• Some file system examples:
  • ~/core/
  • ~/extensions/cockpit/ (empty)
  • ~/extensions/cockpit/add-ons/blue-theme/style.css (Cockpit can use the files in here to override its theme)
  • ~/extensions/cockpit/docs/index.md (documentation)

Explained again:

1. BlueOS Cloud has a registry of docker images (core + extensions) with versions
2. For each docker image, have associated add-ons for each version
3. BlueOS Local shows available add-ons for the extensions and allows user to install them, overlaying those on the file system

Extension with add-on example:

1. Install PingViewer extension, with sonar driver inside (Full BlueOS extension, with API and UI)
2. That extension adds files to ~/extensions/cockpit/add-ons/PingViewer/widget.vue
3. Cockpit can now have a PingViewer widget that accesses data from /xyz/ API