I am having trouble with a container that manages the swap file for our app. I understand that swapfiles are not natively supported by balena, but we require additional memory capacity for running Tensorflow apps on our Jetson Nano-based device, and the internal RAM is falling short with all of the…

Hi there, we do follow SIGTERM=>SIGKILL approach when restarting containers, so all you would have to do, is to implement a SIGTERM hook in your script/app to disable swap. For example, in a bash script, you could use this approach to trap the signal and carry out clean-up.

I’ve been playing around with this with no luck… the container is a simple busybox build, and the start script is as follows: #!/bin/sh delete_swap() { echo "Caught SIGTERM, deleting swap file..." swapoff $SWAPFILE rm $SWAPFILE rm /etc/fstab echo "Swap file deleted" exit $? } tr…

Hi there - we’re checking this with our team, and will get back to you shortly. One thing to check in the meantime: if you’re not seeing the echo in the logs, I’d wonder if you are catching the signal properly. This article may help you, and it should be easy to debug this with a simpler script (…

Thanks for the tips and links - I’ve read through them and tried everything suggested - including using ENTRYPOINT exec /usr/src/app/start.sh instead of CMD ["/bin/sh", "/usr/src/app/start.sh"] that I was previously using to launch the startup script. I even removed everything but the echo line fro…

Hi, looking at yor example I think the issue is with the last line - sleep infinity. Bash will block waiting for the sleep process to exit and will not handle the SIGTERM it receives. You should be able to use one of the following to get the behavior you expect: ... sleep infinity & wait or ... …

hi @drcnyc , just faced a similar issue. Maybe it can help? [image] Best way to set all GPIOs to zero before container shutdown? Product support I would like to ensure that, before a container is shutdown, during the OTA process, the outputs of the IO modules connected to …

Hi there, just to add some info, due to this issue , the supervisor might be killed before the app containers, so if you try to log in after catching the SIGTERM signal you might not see it in the logs, so you shouldn’t judge whether the signal was caught or not based on that. Let us know if Tomasso…

@mtoman your suggestion worked - thank you! I used the sleep infinity & wait approach. @tgirotto I had actually set it up the Dockerfile to use ENTRYPOINT already - so I suspect this is also necessary to make the solution work. Thank you for pointing this out - hopefully this will all help the ne…

Unable to stop container with swap file

Product support

tgirotto July 21, 2020, 11:22am 16

hi @drcnyc, just faced a similar issue. Maybe it can help?

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Unable to stop container with swap file

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