(aws-apigatewayv2): apiEndpoint returns incomplete URL

[moltar]

https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-apigatewayv2.HttpApi.html#apiendpointspan-classapi-icon-api-icon-experimental-titlethis-api-element-is-experimental-it-may-change-without-noticespan

Get the default endpoint for this API.

Not sure if this is intentional, as the docs aren't clear.

But calling apiEndpoint on an API that has a domainName and mappingKey set will produce a wrong URL.

Reproduction Steps

const api = new HttpApi(scope, 'api', {
  domainName: properties.domainName, // example.com
  mappingKey: properties.mappingKey, // foo
})

new CfnOutput(this, 'url', {
  value: api.apiEndpoint,
})

What did you expect to happen?

To have the following resolved value:

https://example.com/foo

What actually happened?

The value resolves to the following:

https://xyz.execute-api.ap-northeast-1.amazonaws.com

Note that the domain name is not applied, and the mapping key is not present.

Environment

• CDK CLI Version : 1.123.0
• Framework Version: 1.123.0
• Node.js Version: v14.17.5
• OS : macOS
• Language (Version): TS

Other

Docs state:

https://docs.aws.amazon.com/cdk/api/latest/docs/aws-apigatewayv2-readme.html#defining-http-apis

You can retrieve the full domain URL with mapping key using the domainUrl property as so -

However, I don't have this prop on the defaultStage.

---

This is 🐛 Bug Report

[nija-at]

As documented, api.apiEndpoint is how you retrieve the execute API endpoint.

To get the domain URL, you will need to use api.defaultStage.domainUrl. I can confirm that all of the APIs are present where they say they are.

You need to check your code on your end. One thing to note - api.defaultStage can be undefined in some cases, so you may need to cast or add a check for your IDE to correctly autocomplete.

[moltar]

I can confirm that all of the APIs are present where they say they are.

Can you please point out where they are? I cannot find it.

aws-cdk/packages/@aws-cdk/aws-apigatewayv2/lib/http/api.ts

Lines 366 to 370 in b0752c5

	/**
	* The default stage of this API
	*/
	public readonly defaultStage: IHttpStage | undefined;

---

aws-cdk/packages/@aws-cdk/aws-apigatewayv2/lib/http/stage.ts

Lines 15 to 65 in b0752c5

	export interface IHttpStage extends IStage {
	/**
	* The API this stage is associated to.
	*/
	readonly api: IHttpApi;
	/**
	* Metric for the number of client-side errors captured in a given period.
	*
	* @default - sum over 5 minutes
	*/
	metricClientError(props?: MetricOptions): Metric
	/**
	* Metric for the number of server-side errors captured in a given period.
	*
	* @default - sum over 5 minutes
	*/
	metricServerError(props?: MetricOptions): Metric
	/**
	* Metric for the amount of data processed in bytes.
	*
	* @default - sum over 5 minutes
	*/
	metricDataProcessed(props?: MetricOptions): Metric
	/**
	* Metric for the total number API requests in a given period.
	*
	* @default - SampleCount over 5 minutes
	*/
	metricCount(props?: MetricOptions): Metric
	/**
	* Metric for the time between when API Gateway relays a request to the backend
	* and when it receives a response from the backend.
	*
	* @default - no statistic
	*/
	metricIntegrationLatency(props?: MetricOptions): Metric
	/**
	* The time between when API Gateway receives a request from a client
	* and when it returns a response to the client.
	* The latency includes the integration latency and other API Gateway overhead.
	*
	* @default - no statistic
	*/
	metricLatency(props?: MetricOptions): Metric
	}

---

aws-cdk/packages/@aws-cdk/aws-apigatewayv2/lib/common/stage.ts

Lines 8 to 26 in b0752c5

	export interface IStage extends IResource {
	/**
	* The name of the stage; its primary identifier.
	* @attribute
	*/
	readonly stageName: string;
	/**
	* The URL to this stage.
	*/
	readonly url: string;
	/**
	* Return the given named metric for this HTTP Api Gateway Stage
	*
	* @default - average over 5 minutes
	*/
	metric(metricName: string, props?: MetricOptions): Metric
	}

[nija-at]

Here -

aws-cdk/packages/@aws-cdk/aws-apigatewayv2/lib/http/stage.ts

Line 183 in 6194ad4

public get domainUrl(): string {

[moltar]

But defaultStage is typed as IHttpStage, not a concrete class HttpStage.

However both IHttpStage, and IStage, which it extends, don't have the domainUrl getter.

[nija-at]

Ah, I missed that. You are correct indeed.

This needs to be fixed.

[nija-at]

The workaround would be to cast it to HttpStage. Can you check if that works?

[moltar]

This does indeed work!

(this.defaultStage as HttpStage).domainUrl

[nija-at]

I have a fix prepared - #16854

[github-actions]

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