Kustomize Problem Statement idealogy

Summary: This article discusses Kustomize, a tool for managing Kubernetes configurations across multiple environments efficiently.

Key Notes

Before diving into what Kustomize is and how to use it, let’s review the problem it addresses and the motivation behind its creation.
The Challenge with Multiple Environments
Consider a simple example using an nginx deployment YAML file that deploys a single nginx pod:
apps/v1
Imagine you have multiple environments—a development environment on your local machine, a staging environment, and a production environment. You need your deployment to behave differently in each, with varying numbers of replicas. For example:
1 replica in development,
2–3 replicas in staging, and
5–10 replicas in production.
If you use a single nginx deployment YAML file, each environment would deploy only one replica. A common workaround is to create separate directories (dev, stg, prod) and duplicate your configuration file while modifying only the replica count.
Example Directory Structure
Your directory might be organized as follows:
dev:
stg:
prod:
For instance:
To deploy the configuration, you would run a command for each environment, for example:
$
dev/
deployment.apps/nginx-deployment
For the staging environment:
stg/
This command creates two nginx pods for staging.
The directory structure might end up looking like this:
├── nginx-depl.yml