Graceful shutdown of containers during update or shutdown

Product support balenaOS
#1

Hi all,

I’m wondering how containers will be killed when an update is being installed or when the shutdown / reboot endpoint is called via the supervisor API. Is there a graceful shutdown period with a SIGTERM signal, or is the container just being killed instantly?

I searched in the docs and forum, but couldn’t find an answer.

Thanks in advance!

#3

Hi Bart,

Thanks for the great question! When the reboot/shutdown endpoint is called, the supervisor will make a call to stop the engine which as outlined by the docker documentation, will first send a SIGTERM and then a SIGKILL to the main process inside the container.

When using Application Update Locks, the reboot endpoint request will fail as the application takes priority.

You can see more information on how those endpoints work on the supervisor API documentation

Please let us know if there is more information we can provide.