An Introduction to Kustomize
kustomize is a tool designed to let users “customize raw, template-free YAML files for multiple purposes, leaving the original YAML untouched and usable as is” (wording taken directly from the kustomize GitHub repository). Users can run kustomize directly, or—starting with Kubernetes 1.14—use kubectl -k to access the functionality (although the standalone binary is newer than the functionality built into kubectl as of the Kubernetes 1.15 release). In this post, I’d like to provide an introduction to kustomize.
In its simplest form/usage, kustomize is simply a set of resources (these would be YAML files that define Kubernetes objects like Deployments, Services, etc.) plus a set of instructions on the changes to be made to these resources. Similar to the way make leverages a file named Makefile to define its function or the way Docker uses a Dockerfile to build a container, kustomize uses a file named kustomization.yaml to store the instructions on the changes the user wants made to a set of resources.
Here’s a simple kustomization.yaml file:
resources:
- deployment.yaml
- service.yaml
namePrefix: dev-
namespace: development
commonLabels:
environment: development
This article won’t attempt to explain all the various fields that could be Continue reading
