Do instances based off of an image get updated if the image itself is updated with the auto_update feature even if they were created before the update?

[Dan826]

• Is there a way to trigger auto_update manually so I can test this without waiting for the minimum interval which would be an hour?
• Are the configurations images.auto_update_cached and images.auto_update_interval supposed to be set on the remote server or the client that’s launching the instance?
• Would it trigger the auto_update feature if I renamed the alias for or deleted the image itself and replaced it with a new one that had the same alias? Is this the common practice?
• Would any instances that were created from the image before the update get updated as well? If they do:
  • Does this trigger the cloud-init functionality in the instance if it’s present?
  • Is there any down time for instances based off of the image when it’s updated?

[stgraber (Stéphane Graber)]

@Dan826

Is there a way to trigger auto_update manually so I can test this without waiting for the minimum interval which would be an hour?

incus image refresh

@Dan826

Are the configurations images.auto_update_cached and images.auto_update_interval supposed to be set on the remote server or the client that’s launching the instance?

They affect the server that they’re set on, not other servers downloading from it.

@Dan826

Would it trigger the auto_update feature if I renamed the alias for or deleted the image itself and replaced it with a new one that had the same alias? Is this the common practice?

The auto-refresh simply has Incus reach out to the origin server every few hours and see if the alias now points to a different image, if it does, that image is downloaded.

@Dan826

Would any instances that were created from the image before the update get updated as well? If they do:

No. There’s effectively no way to “rebase” an instance onto a new image.
The auto-refresh feature is here solely so that the latest image is already present on the system for the next time you create an instance from it.

[votsalo]

@stgraber

There’s effectively no way to “rebase” an instance onto a new image.

Doesn’t “incus rebuild” do this?

[stgraber (Stéphane Graber)]

It won’t “rebase it”, it will replace its rootfs with the new image.

What I mean by rebase is that the user’s own changes would somehow be kept, this isn’t possible. Instead rebuild is roughly equivalent to deleting the instance and creating a new one from a new image, except that the Incus side configuration (attached devices, MAC address, …) is all conserved.