docker-compose/compose/config/service_schema.json

{
  "$schema": "http://json-schema.org/draft-04/schema#",

  "type": "object",

  "properties": {
      "name": {"type": "string"}
  },

  "required": ["name"],

  "allOf": [
    {"$ref": "fields_schema.json#/definitions/service"},
    {"$ref": "#/definitions/service_constraints"}
  ],

  "definitions": {
    "service_constraints": {
      "anyOf": [
        {
          "required": ["build"],
          "not": {"required": ["image"]}
        },
        {
          "required": ["image"],
          "not": {"anyOf": [
            {"required": ["build"]},
            {"required": ["dockerfile"]}
          ]}
        },
        {
          "required": ["extends"],
          "not": {"required": ["build", "image"]}
        }
      ]
    }
  }

}