How are failures of automatic (unattended) updates handled?

[gdk22]

I am planning to set up Nextcloud AIO for my family. The daily backup with automatic updates looks most compelling to me. Before turning it on, I’d like to consider a potential failure scenario that a container update fails.

In How to update the containers, you write: “Otherwise you won't be able to restore your instance easily if something should break during the update”.

I miss the picture how this will work, because the newly updated, now “latest” containers have already been pulled and started. In order to “restore the instance”, per my understanding, the previous versions of the container would need to be restored (pulled and started), e.g. to get back to the prior database schema that fits to the backup data. I couldn't find a description of it. How does it work?

I do not see a way to test this scenario, because all updates worked smoothly so far. Still, I feel I need some more insight into the procedure to get confident for such a scenario to avoid a disaster.

[szaimen]

Hi, the container images only include ephemeral files like the php runtime for example. All important and persistent data like the database, the Nextcloud installation and files are stored in volumes and included in the backup. If you restore a backup, you are going to restore these kind of files. The images itself should usually not cause any problems as they are ephemeral.

If you really want to also pin the images, you could do so by using a different tag for the mastercontainer like for example this one: https://hub.docker.com/layers/nextcloud/all-in-one/20250106_094420/images/sha256-5fd583f66089deb6f1deb849d989e74ed229d3aa565364f362b13859b22b4a65. However note that in that case automatic updates are not going to work anymore since you pinned the images to this specific version.

[gdk22]

TY, that makes it clear! I'd think this answer may be helpful to other readers of What is getting backed up by AIO's backup solution?. The first sentence could be extended like this: "Backed up will get all important data of your Nextcloud AIO instance required to restore the instance, like the database, [...]" - I'll create a PR for this.