add kustomize example

kustomize/overlays-example/overlays/production/deploymentconfig.yaml

@@ -0,0 +1,6 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: overlays-example
+spec:
+  replicas: 4

kustomize/overlays-example/overlays/production/kustomization.yaml

@@ -0,0 +1,20 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+bases:
+- ../../base
+
+commonLabels:
+  appStageTag: production
+
+generatorOptions:
+  # commonLabels will not be respected by generator
+  labels:
+    app: overlays-example
+    app.kubernetes.io/managed-by: kustomize
+    appStageTag: production
+
+
+patchesStrategicMerge:
+- deploymentconfig.yaml
+# - service.yaml