{
  "$schema": "http://json-schema.org/schema#", 
  "required": [
    "key"
  ], 
  "type": "object", 
  "description": "Selects a key from a ConfigMap.", 
  "properties": {
    "key": {
      "type": [
        "string", 
        "null"
      ], 
      "description": "The key to select."
    }
  }
}