API Gateway V2 ALB Integration - Multiple Route Creation Failure

[kristof-kasa]

Hey!

I'm not sure if this is a bug or if I'm misunderstanding something.

I have a routes array (100+ items in it), which contains all routes for my service, but whenever I'm trying to deploy this solution, it will fail with the following error:

Unable to retrieve listener port and load balancer DNS name from ELB listener arn [listener-arn]. Please check that ELB listener exists in account [account-id]

However, when I only want to deploy, say, 50 routes (not every route at once), it works just fine.

Here is a small snippet of how I'm trying to do it:

import * as apigw from 'aws-cdk-lib/aws-apigatewayv2';
import * as apigwInt from 'aws-cdk-lib/aws-apigatewayv2-integrations';
import * as elbv2 from 'aws-cdk-lib/aws-elasticloadbalancingv2';
import { Construct } from 'constructs';

class ApiGatewayWithAlbIntegration extends Construct {
  constructor(scope: Construct, id: string) {
    super(scope, id);

    // Create or import ALB listener
    const listener = elbv2.ApplicationListener.fromLookup(this, 'Listener', {
      listenerArn: 'arn:aws:elasticloadbalancing:region:account:listener/app/alb/id/id'
    });

    // Create VPC Link
    const vpcLink = new apigw.VpcLink(this, 'VpcLink', {
      vpc: vpc
    });

    // Create HTTP API
    const api = new apigw.HttpApi(this, 'Api');

    // This works - single route with proxy
    const proxyParameterMapping = new apigw.ParameterMapping()
      .appendHeader('custom-header', apigw.MappingValue.custom('value'))
      .overwritePath(apigw.MappingValue.custom('/$request.path.proxy'));

    new apigw.HttpRoute(this, 'ProxyRoute', {
      httpApi: api,
      routeKey: apigw.HttpRouteKey.with('/{proxy+}', apigw.HttpMethod.ANY),
      integration: new apigwInt.HttpAlbIntegration('Integration', listener, {
        vpcLink,
        parameterMapping: proxyParameterMapping
      })
    });

    // This fails - multiple routes in sequence
    const routes = [
      { path: '/users', method: apigw.HttpMethod.GET, backendPath: '/api/v1/users' },
      { path: '/users', method: apigw.HttpMethod.POST, backendPath: '/api/v1/users' },
      { path: '/products', method: apigw.HttpMethod.GET, backendPath: '/api/v1/products' },
      // ... more routes
    ];

    for (const route of routes) {
      // Each route needs its own parameter mapping to forward the correct path
      const routeParameterMapping = new apigw.ParameterMapping()
        .appendHeader('custom-header', apigw.MappingValue.custom('value'))
        .overwritePath(apigw.MappingValue.custom(route.backendPath));  // This is crucial

      new apigw.HttpRoute(this, `Route-${route.path}-${route.method}`, {
        httpApi: api,
        routeKey: apigw.HttpRouteKey.with(route.path, route.method),
        integration: new apigwInt.HttpAlbIntegration(
          `Integration-${route.path}-${route.method}`,
          listener,
          {
            vpcLink,
            parameterMapping: routeParameterMapping,
            method: route.method
          }
        )
      });
    }
  }
}

• So, deploying in multiple steps is working, but far from ideal.
• The listener exists, so the error does not make any sense to me
• Is this a known limitation with the ALB listener? Or am I throttling the API to retrieve the listener when the HttpAlbIntegration is created?
• Are there best practices for creating multiple routes with ALB integrations that I'm not aware of?

Few notes:

• I cannot use {proxy+} since I have other routes that should not be accessible via this gateway for my service, so I have to specify which exact routes users can access
• I must have different parameter mappings for each route
• Currently, I'm using {proxy+} with an authorizer lambda, which just checks the route and forwards it to the service whenever needed, but I thought I didn't need the authorizer lambda for this after all.

Versions:

• "aws-cdk": "^2.1013.0"
• "aws-cdk-lib": "^2.194.0"
• "constructs": "^10.4.2"

[github-actions[bot]]

Hello! Reopening this discussion to make it searchable.

[kristof-kasa]

Closing this, as this was answered in github issues as a bug.
#35004

[github-actions[bot]]

Hello! Reopening this discussion to make it searchable.