Simpler ConfigMap overriding

configmaps.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    label1: value1
  name: service1
data:
  PVC: "false"
  ENDPOINT: http://internal-api:8080/api/v1/scan
  PATH: /test1
---
apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    label1: value1
  name: service2
data: {}

customize_configmaps.yaml

#@ load("@ytt:data", "data")
#@ load("@ytt:overlay", "overlay")

#@ for app_name in dir(data.values.configmaps):
#@   if hasattr(data.values.configmaps[app_name], "dev"):
#@overlay/match by=overlay.subset({"kind": "ConfigMap", "metadata": {"name": app_name}})
---
#@overlay/match-child-defaults missing_ok=True
data: #@ data.values.configmaps[app_name].dev
#@   end
#@ end

schema.yaml

#@data/values-schema
---
configmaps:
  service1:
    dev:
      DB_HOST: 192.168.1.1
      DB_USER: service1_dev
  service2:
    dev:
      DB_HOST: 192.168.1.2
      DB_USER: service2_dev