Kustomize

Question 1

What is kustomize?

Answer 1

• kubernetes native tool
• for customizing kubernetes manifest files
• doesnt require complex templating or additional tools
• uses yaml
• built into kubectl

Question 2

How can you use kustomize?

Answer 2

kubectl apply -k < kustomize-directory >

While having inside a kustomization.yaml

Question 3

Why is kustomize used?

Answer 3

• helps customizing config files in a template free way
• provides methods and common values like generators to make customization easier#
• common values help making labels, names and annotations consistent
• generators let you define secrets and config files for you pods
• easiliy define changes for different environments
• done by using patching and overlays, that needs a single folder for each environment
• easy to use

Question 4

What are basic folders used by kustomize and what do they contain?

Answer 4

• base:
• overlay: contains environment specific folders which contain the kustomization.yaml and config.properties

Question 5

What does the kustomization.yaml file contain?

Answer 5

• resources: which manifest files should be included in kustomization
• common attributes: specify common configurations that you want to be consistent, like labels, annotations and names
• generators: for creating/managing configmaps and kubernetes secrets

Question 6

Show an example for a kustomization.yaml

Answer 6

resources:
- deployment.yaml
- service.yaml

commonLabels:
app: mykustomapp

commonAnnotations:
app: mykustom-annotations

namePrefix:
kustom-

nameSuffix:
-v1

configMapGenerator:
- name: mykustom-map
env: config.properties

Question 7

Show an example for an overlay implementation

Answer 7

Via folder structure with patch-files.

Folder structure:
– overlays
|– dev
|– config.properties
|– kustomization.yaml
|– replicas.yaml

kustomization.yaml

namespace: prod
patches:
- replicas.yaml

configMapGenerator:
- name: mykustom-map
env: config.properties

Question 8

How do you take a loot at the kustomize file that is going to be applied?

Answer 8

‘kubectl kustomize’