Cannot find right method to import existing vpc with ec2.Vpc.fromLookup or ec2.Vpc.fromVpcAttributes

Issue: I am trying to import an existing vpc to deploy few lambda, ecs and albs in private subnets. Running into issues when trying to import the vpc using ec2.Vpc.fromLookup or ec2.Vpc.fromVpcAttributes.

The existing vpcid, azs, privatesubnets are exported as dev-vpcId. - value: ‘vpc-xxxxx’ dev-azs - value: ‘us-east-1a,us-east-1b’ dev-privateSubnets - ‘subnet-xxxx,subnet-yyyy’

    const vpc = ec2.Vpc.fromVpcAttributes(this,'vpc',{
      vpcId: Fn.importValue(envName+'-vpcId'),
      availabilityZones: Fn.split(',',Fn.importValue(envName+'-azs')),
      privateSubnetIds: Fn.split(',',Fn.importValue(envName+'-privateSubnets')),
    })

Error

...../node_modules/@aws-cdk/core/lib/private/resolve.ts:94
      throw new Error('Found an encoded list token string in a scalar string context. Use \'Fn.select(0, list)\' (not \'list[0]\') to extract elements from token lists.');
            ^
Error: Found an encoded list token string in a scalar string context. Use 'Fn.select(0, list)' (not 'list[0]') to extract elements from token lists.

with ec2.Vpc.fromLookup() we cannot use import values

    const vpc = ec2.Vpc.fromLookup(this, 'vpc',{
      vpcId: Fn.importValue(envName+'-vpcId')
    })

Error

..../node_modules/@aws-cdk/aws-ec2/lib/vpc.ts:1040
      routerId: natGatewayId,
            ^
Error: All arguments to Vpc.fromLookup() must be concrete (no Tokens)

Please advise on the right method to import an existing vpc with details from the export values.

---

This is a 📕 documentation issue

[redbaron]

Fn.importValue executed during CloudFormation run , but ec2.Vpc.fromLookup runs before CF stack is submitted.

I’d try to give up Fn.importValue and hardcode map { dev: 'vpc-xxx', prod: 'vpc-yyyy' } and use these directly in ec2.Vpc.fromLookup

[pandrel-aws]

@pandrel Have you found the fix for this problem. I am currently facing the same issue.

I am using the ec2.Vpc.fromLookup() with tags option to import an existing vpc.

example:

    const envName = 'dev' // passed from construct stack props but using fixed value for example
    const vpc = ec2.Vpc.fromLookup(this, 'vpc', {
      tags: { 'envName': envName}
    })