Working with Kustomize

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: prod
namePrefix: prod-
commonLabels: { env: prod, owner: platform }
resources:
- deployment.yaml
- service.yaml
patches:
- path: replica-patch.yaml
images:
- name: nginx
  newTag: 1.27-alpine

kubectl apply -k overlays/prod
kubectl diff -k overlays/prod
kubectl delete -k overlays/prod

# replica-patch.yaml
apiVersion: apps/v1
kind: Deployment
metadata: { name: web }
spec:
  replicas: 5

patches:
- target: { kind: Deployment, name: web }
  patch: |-
    - op: replace
      path: /spec/template/spec/containers/0/image
      value: nginx:1.27
    - op: add
      path: /metadata/annotations/owner
      value: platform

namePrefix: prod-
nameSuffix: -v2

configMapGenerator:
- name: app-config
  literals: [LOG_LEVEL=info, FEATURE_X=true]
  files: [config.yaml]
  options: { disableNameSuffixHash: false }

secretGenerator:
- name: db
  type: Opaque
  envs: [.env.prod]
  options: { disableNameSuffixHash: false }

commonLabels:
  app.kubernetes.io/managed-by: kustomize
  env: prod
commonAnnotations:
  owner: platform-team

app/
├── base/
│   ├── kustomization.yaml
│   ├── deployment.yaml
│   └── service.yaml
└── overlays/
    ├── dev/kustomization.yaml      # resources: [../../base]
    ├── stage/kustomization.yaml
    └── prod/kustomization.yaml

images:
- name: my-app
  newName: registry.io/team/my-app
  newTag: v2.3.1
  digest: sha256:abcd...

kustomize build overlays/prod
kustomize build overlays/prod | kubectl apply -f -
kustomize build overlays/prod --enable-helm   # render Helm charts