Augustine's Notes

Patches Intro

2 min read

Patches Intro

Source: https://notes.kodekloud.com/docs/CKA-Certification-Course-Certified-Kubernetes-Administrator/2025-Updates-Kustomize-Basics/Patches-Intro/page

Summary: This article explores using patches with Kustomize to modify Kubernetes configurations for targeted updates to specific resource sections.

Key Notes

  • In this lesson, we explore how to use patches with Kustomize to modify Kubernetes configurations. Patches offer a granular approach to updating specific sections of a Kubernetes resource, which is especially useful when you want to target one or a few objects rather than applying a broad change. For instance, if you need to update the replica count in a Deployment, a tailored patch that specifically addresses that object is ideal.
  • Patch Parameters
  • When creating a patch, you must specify three key parameters:
  • Operation Type:
  • add:
  • remove:
  • replace:
  • Target:
  • Value:
  • Inline Patch Example
  • apps/v1
  • kustomization.yaml
  • metadata/name
  • |
    • op: replace
  • path: /metadata/name
  • value: web-deployment
  • After applying this patch, the rendered Deployment configuration becomes:
  • Replacing the Replica Count
  • Next, let’s update the number of replicas. Assume the original Deployment configuration has one replica and you want to change it to five. The starting configuration is as follows:
  • path: /spec/replicas
  • value: 5
  • After applying this patch, the updated Deployment configuration appears as:
  • Patch Strategies: JSON 6902 vs. Strategic Merge Patch

Graph View