How to check for changes in k8s upgrades
Confidentiality:
Purpose
When upgrading Giant Swarm releases you will notice that the Kubernetes version is also being upgraded. As part of the upgrade process, it should be a habit to check for the newest changes upstream. This ensures that the diffs, deprecations, and new features from an upstream Kubernetes perspective are known to the customer.
There is not a right or wrong way to go about this process because there is no single tool that simply gives all of the answers. However, the following tools combine to give a nice overview of the important changes. Let us know if you have thoughts or recommended tools as well!
Tools
Pluto This one is a tool that will show you deprecated APIs in your code, helm charts, and resources.
Sysdig Blog Sysdig is writing a good summary on the major changes in K8s that can be used as reference.
k8s.io Release Notes All kubernetes release notes.
Giant Swarm Releases Our own release page and we try to give you a better overview on the important changes. Tip: Once we deprecate a release, it is moved to “archived”, so you might need to dig in there to find our past versions where the K8s version is changing.
Giant Swarm
When upgrading to a new Giant Swarm version, another idea to see the changes would be to use the tool yamldiff. Using Giant Swarm versions as examples: Let’s say the current version is 17.4.4 and the target version is 18.3.0. To use yamldiff you would input the YAML files from both current release on the left and target release on the right to learn about the changed components.