Custom Update Agents

This section shows how to create a custom update agent—“SOTA client”—for your platform. Aktualizr-Lite is a general purpose SOTA client that fits many needs. However, some cases require more control over the update agent than aktualizr-lite and the “hooks” system can provide. In these cases, a custom SOTA client can be written in C++ using the aktualizr-lite API.

Using the Custom SOTA Client Example

The example SOTA client in aktualizr-lite is a great place to start experimenting. The meta-lmp layer includes a recipe that runs this example as the default SOTA client. Later, this can serve as an example to copy/paste into a Factory specific recipe.

Users can build this custom client into their LmP image with a small addition to meta-subscriber-overrides.git:

git clone -b devel https://source.foundries.io/factories/<factory>/meta-subscriber-overrides.git
cd meta-subscriber-overrides
echo 'SOTA_CLIENT = "custom-sota-client"' >> conf/machine/include/lmp-factory-custom.inc

Forking the custom SOTA Client

Producing a factory-specific SOTA client can be done by:

1. Creating a Git repository for your custom code. Copying the examples/custom-client-cxx directory is a good place to start.
2. Copying the custom-sota-client recipe from meta-lmp into meta-subscriber-overrides/recipes-sota.
3. Changing the custom-sota-client_git.bb Git references (SRC_URI, BRANCH, SRCREV) to point at your new sources.