json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "Build metadata plugin manifest",
      "type": "object",
      "properties": {
          "provider": {
              "type": "string",
              "enum": [
                  "ec2"
              ]
          },
          "plugins": {
              "type": "object",
              "properties": {
                  "build_metadata": {
                      "type": "object",
                      "properties": {
                          "path": {
                              "type": "string"
                          }
                      },
                      "required": [
                          "path"
                      ]
                  }
              },
              "required": [
                  "build_metadata"
              ]
          }
      },
      "required": [
          "plugins"
      ]
  }