Kubernetes containers, fleet management, and applications

Training Guide

Helm

Finally, I'll look at a term from the Kubernetes world that regularly pops up in discussions: Helm [5], a package manager in the Kubernetes context.

If you use Rook or Istio, you implicitly roll out several containers that use different images. Moreover, you need to store a set of CRDs in Kubernetes, and custom controllers might be required, as well. If you wanted to handle all of these tasks manually, you would have to work your way through a long to-do list.

Instead, you could use a Helm chart to define all the necessary resources, properties, and details, which can be rolled out directly in Kubernetes with just a few commands. At the same time, Helm calls Kubernetes to create the resources belonging to the service. This principle is similar to the way classic package managers such as Rpm and Dpkg work, but it relies on container images and comes with a plethora of control information (Figure 6).

Figure 6: The Helm Kubernetes package manager stores ready-to-run definitions of custom resources and custom controllers in the fleet manager to facilitate their deployment.

Conclusions

The most complicated part of getting to know Kubernetes is familiarizing yourself with its jargon, which is riddled with many special terms and acronyms. Even if you are not planning a Kubernetes setup in the near future, you will at least know what other people are talking about. Of course, a crash course like this article can only hope to cover the basic concepts. If you want to roll out Kubernetes yourself, you definitely need to plan for some preparation time to get up to speed.

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