Cancel an active release download

Consider the following situation; You have a device with LTE signal that is pinned to X release. Everything is ready and prepped for new release to download but while downloading the connection becomes very unreliable and download is slowed down considerably. This download is now impacting the device services that require low latency for NTRIP and also emitting EMI which is problematic for the environment the device is in. Of course these issues could exist with a fast download speed but now because of the degraded speed they are prolonged with no option but to change pinned release and restart the device.

In this scenario device pinning was used but could not have prevented this. Therefor, it is believed that offering a way to cancel an active release download is needed.

This raises some important questions;

What happens to the pinned release target? Does that revert to the currently downloaded release so the Supervisor doesn't keep trying to download.
How does this affect various update strategies ? delete-then-download seems to be the most troublesome strategy

Related HQ issue Related JF ticket

balena-os / balena-supervisor

Cancel an active release download #1399