Snaps are not synchronized during boot-up sequence

[Radu Caciora]

Hi all,

In our device with Ubuntu Core16 we are getting instabilities because the snaps are not synchronized at device boot-up.

Our device needs to initialize and run the different snaps in a certain order in order to successfully power up the network interfaces.

The instabilities were seen when moving and testing to a larger scale. We realized that because of this limitation we cannot guarantee that the our network interface is power up correctly.

In order to workaround this issue while loops were added in our snaps in order to check the dependencies and the state of our network interface before moving further with the initialization.

Do you know when the snaps synchronization at boot up is planned to be release ? Will this be available somewhere in Q12019?

Thanks & BR,
Radu

[Zygmunt Krynicki (zyga)]

I'm not aware of details of synchronization plans between separate snaps but we have the following broad set of opinions:

- socket activated services are optimal for synchronization because it is race free
- services ought to cope with various connections disappearing and be able to reconnect without failing
- services should not *depend* on being "online" because that is vague and hard to guarantee

Having said that, I believe we discussed being able to do some coordination at the level of apps inside one snap and _perhaps_ at the level of snaps form one publisher.

I would encourage you to discuss this at the snapcraft forum: https://forum.snapcraft.io and engage with the snapcraft architects.