AWS CDK Api Gateway 模型引用依赖性 - 模型引用必须采用规范形式

Question

当其中一个模型引用另一个模型时，我尝试使用 aws CDK 同时添加多个模型。 例如：

  "Gender": {
    "contentType": "application/json",
    "modelName": "GenderModel",
    "schema": {
      "type": "string",
      "enum": [
        "Not Specified",
        "Male",
        "Female",
        "Non-Binary"
      ],
      "schema": "http://json-schema.org/draft-04/schema#",
      "title": "GenderModel"
    }
  },

和

"Requirements": {
    "contentType": "application/json",
    "modelName": "RequirementsModel",
    "schema": {
      "type": "object",
      "properties": {
        "gender": {
          "ref": "https://apigateway.amazonaws.com/restapis/${Token[TOKEN.791]}/models/GenderModel"
        }
      },
      "required": [
        "gender",
      ],
      "additionalProperties": false,
      "schema": "http://json-schema.org/draft-04/schema#",
      "title": "RequirementsModel"
    }
  },

当我部署时失败

Model reference must be in canonical form

据我所知，这失败了，因为

GenderModel

不存在。如果我首先在堆栈中添加

GenderModel

，然后添加

RequirementsModel

并再次部署，它就可以正常工作，因为

GenderModel

是之前创建的。如果我想同时创建两个模型，它将失败。 我试图确保

addModel

调用的顺序是正确的，但似乎不起作用。

找到解决方案

似乎您必须添加显式指定依赖项。

modelB.node.addDependency(modelA)

这将避免错误并按正确的顺序添加模型

Answer 1

问题是

https://apigateway.amazonaws.com/restapis/${Token[TOKEN.791]}/models/GenderModel

，特别是

${Token[TOKEN.791]}

部分。当未创建 API 时，在 CloudFormation 合成时，id 未知且使用占位符值 - https://docs.aws.amazon.com/cdk/latest/guide/tokens.html

您可以使用

Ref

内部函数参考构建模型

const getModelRef = (api: RestApi, model: Model): string => 
    Fn.join(
        '',
        ['https://apigateway.amazonaws.com/restapis/',
        api.restApiId,
        '/models/',
        model.modelId]);

Answer 2

    "ModelCountry":
    {
        "Type" : "AWS::ApiGateway::Model",
        "Properties" : {
            "ContentType" : "application/json",
            "Description" : "Country",
            "Name" : "Country",
            "RestApiId" : {"Ref": "WebApi"},
            "Schema": {
                "$schema": "http://json-schema.org/draft-04/schema#",
                "title": "ModelCountry",
                "properties": {
                    "Id": {"type": "number"},
                    "Name": {"type": "string"},
                    "Alpha2Code": {"type": "string"},
                    "Alpha3Code": {"type": "string"},
                    "NumericCode": {"type": "string"},
                    "PhoneCode": {"type": "string"}
                }
            }
        }
    },
    "ModelState":
    {
        "Type" : "AWS::ApiGateway::Model",
        "DependsOn" : "ModelCountry",
        "Properties" : {
            "ContentType" : "application/json",
            "Description" : "State",
            "Name" : "State",
            "RestApiId" : {"Ref": "WebApi"},
            "Schema": {
                "$schema": "http://json-schema.org/draft-04/schema#",
                "type": "object",
                "title": "ModelState",
                "properties": {
                    "Id": {"type": "number"},
                    "Name": {"type": "string"},
                    "Country": {"$ref": {"Fn::Join" : ["", ["https://apigateway.amazonaws.com/restapis/", {"Ref": "WebApi"}, "/models/", {"Ref": "ModelCountry"}]]}},
                    "Alpha2Code": {"type": "string"}
                }
            }
        }
    }