DDI API

The hawkBit update server provides REST resources which are consumed by the device to retrieve software update tasks. This API is based on HTTP standards and a polling mechanism.

{{% note %}} In DDI the target is identified using a controllerId. Controller is used as a term for the actual service/client on the device. That allows users to have in some cases even multiple clients on the same target for different tasks, e.g. Firmware update and App management. {{% /note %}}

State Machine Mapping

For historical reasons the DDI has a different state machine and status messages than the Target State Machine of the hawkBit update server.

This is kept in order to ensure that DDI stays compatible for devices out there in the field. A future version "2" of DDI might change that. DDI also defines more states than the update server, e.g. multiple DDI states are currently mapped by the DDI implementation to RUNNING state. It is possible that in the future hawkBit will fully leverage these additional states.

The DDI API allows the device to provide the following feedback messages:

DDI `status.execution` type	handling by update server	Mapped ActionStatus type
CANCELED	This is send by the target as confirmation of a cancellation request by the update server.	CANCELED
REJECTED	This is send by the target in case an update of a cancellation is rejected, i.e. cannot be fulfilled at this point in time. Note: the target should send a CLOSED->ERROR if it believes it will not be able to proceed the action at all.	WARNING
CLOSED	Target completes the action either with `status.result.finished` SUCCESS or FAILURE as result. Note: DDI defines also a status NONE which will not be interpreted by the update server and handled like SUCCESS.	ERROR (DDI FAILURE) or FINISHED (DDI SUCCESS or NONE)
DOWNLOAD	This can be used by the target to inform that it is downloading artifacts of the action.	DOWNLOAD
DOWNLOADED	This can be used by the target to inform that it has downloaded artifacts of the action.	DOWNLOADED
PROCEEDING	This can be used by the target to inform that it is working on the action.	RUNNING
SCHEDULED	This can be used by the target to inform that it scheduled on the action.	RUNNING
RESUMED	This can be used by the target to inform that it continued to work on the action.	RUNNING