clout-init Coming To SUSE Images in Azure
OK, that was the announcement, thanks for reading. Well, not quite so fast, let’s take this apart a bit and look at the details, because as always the interesting bits are in the detail.
Let me start in the future and then work backwards. In the not too distant future, July 2020, SLE 15 SP2 will see the light of day. This means SUSE Linux Enterprise Server (SLES) and SUSE Linux Enterprise Server For SAP Applications (SLES For SAP) will see image refreshes per our life-cycle. Also SUSE Manager 4.1 is planned to be released at the same time on top of SLES 15 SP2. All these images will have cloud-init as the instance initialization.
Switching to cloud-init allows the SUSE images to be added to the group of images in Azure that get the faster provisioning treatment. Meaning you should eventually get to access your instances faster than is the case today. The details on this still need to be worked out. The parts of WALA that handle dynamic events in the instance, i.e. extension handling remain untouched, cloud-init takes over the provisioning, meaning user creation, ssh key injection, host name seting user data handling etc. Also this change does not have an effect on cloud-netconfig.
In the hopes of not create too much of a surprise, as of today we have a SLES 15 SP1 images available that also use cloud-init for instance initialization. Images are available in all Public Azure regions as “suse:sles-15-sp1-basic:cloud-init-preview:latest” and “suse:sles-15-sp1-basic:gen2-cloud-init-preview:latest“. These images will not be treated as part of the life-cycle, and will eventually, more on this in a bit, just go away. Meaning don’t create any scripts that use these new images in production if you are not prepared to change the scripts to point to new images when the time comes. Again, these cloud-init enabled preview images will go away without warning when….
Before I explain the condition when these SLES 15 SP1 images with cloud-init go away without warning let me finish the thought about using them in a production setting. These preview images are fully supported. They are on-demand images and the only difference to “regular” SLES 15 SP1 images is that cloud-init is used for provisioning. If you want to start new images and would rather have instances that are provisioned by cloud-init, use these in a production setting as you see fit. Just be mindful that when you use these URNs in scripts that provision instances those scripts will be broken when….
And now to the condition/goal about when these SLES 15 SP1 images with cloud-init will go away. The idea is that by the time the next image refresh per our life-cycle comes around (scheduled towards the end of May) we’ll have all image builds switched over and tested and the next refresh will bring cloud-init to all images that are actively maintained, meaning SLE 15 SP1 and SLE 12 SP5 based images. As soon as cloud-init is in our regular images the preview images will go away, without warning. This also means that the disappearance of these two images is an indication that cloud-init is fully enabled.
While the cloud-init train is not stoppable, meaning if you depend on anything the initialization code does, you will have to adjust to cloud-init, it can be slowed down if necessary. Please test the new images and depending on your situation provide feedback to Microsoft support, SUSE Support or a short comment here on this site.