Release/Update Policy for Official Images
The SWITCHengines team will keep your official images safe and fresh. This is how we do this.
Note that this page is about images, from which instances can be created, not about the software on existing instances. As described elsewhere, once an instance is running, it should, by default, keep itself up to date by periodically downloading and installing vendor-supplied updates.
Updating an Official Image
From time to time—see below—we will replace official images with updated versions. Those versions will generally be backwards-compatible: Everything that worked before should work after the update.
When an update is released, the previous version will be deprecated and hidden from view to normal users. Existing instances based on an old image will continue to work. But new instances can only be created from the new images. If (and only if :-) you require access to a deprecated image, contact support in the usual way, and we can exceptionally make it available to you.
Frequency of Updates
We will update images when:
- There is an official update release from the upstream distributor. Example: Ubuntu 14.04.3 comes out—we will replace our existing 14.04 image with one based on 14.04.3.
- There is an important security fix. "Important" may mean that it was widely publicized, or that we decide that there is a high risk for you to start new instances from unpatched images.
- "We think it's time" to catch up with normal updates. The idea is that when you create a new instance from an official image, and perform a normal package update, this should not result in a huge upgrade. We realize that this is a squishy definition; the period will also depend on the update policy of the underlying distributions. It may vary between a few weeks for a system with frequent updates, and several months for systems with rare updates.
Start and End of Support
For operating system distributions where we already maintain official images, we will try to add official images when a new major release appears.
We will also consider adding new images of general interest, as long as we think we can support them with the resources we have. A good way to propose a new image would be through the SWITCH cloud forum, because that allows other SWITCHengines users to comment.
We will stop supporting official images when it becomes too difficult for us to maintain them safe and fresh. Usually this will happen when the "upstream" distribution stops releasing updates. The length of these support cycles can vary widely between distributions and versions. Keep this in mind when choosing an image! For example, the "LTS" (long-term support) releases of Ubuntu GNU/Linux will be supported by the upstream distributor (Canonical) for five years, whereas intermediate versions only receive updates during nine months or so.