Leveraging Kustomize for Kubernetes Manifests

Chapter 1. Kubernetes Application Deployment and Reuse

Across the enterprise and cloud environments, Kubernetes has achieved unparalleled dominance as the platform for running containerized workloads. It has done this, in part, by automating and simplifying the key functions needed to ensure reliable hosting, scheduling, and management of workloads. And it maintains this throughout an application’s life cycle.

Yet, ironically, until the introduction of some of the tools we will discuss here, the process for working with the specifications for Kubernetes workloads (also known as manifest) was not automated or simplified. For early Kubernetes users (and some today), managing these requirements was a high-cost activity up front, and a potential high cost any time that reuse was needed.

An approach to help with the situation was introduced with a tool called Helm. Helm provided a way to make Kubernetes manifests into templates and insert values for the template at deployment time. It also made simple changes at execution time possible, such as changing case and inserting text based on some condition. And it enabled managing sets of manifests as a group when deployed to Kubernetes.

Helm represented a significant improvement over basic tooling like the kubectl command-line interface to manage manifests. But the overall effort and knowledge to convert manifests to the Helm format, along with the corresponding effort to maintain them, could be complex.

Manifests that were changed to work ...