Unable to extract the values using cdk synth command for Fn.importValue

General Issue

Fn.importValue unable to fetch the value and still returning Tokens

The Question

Hi Team,

I have an implementation where i need to fetch the existing ECS Cluster details. I have the import values from the VPC and Security Group of another base stack. However, While using the Fn.importValue i am getting an error :

All arguments to look up a security group must be concrete (no Tokens)

Here is my source code ecs.Cluster.fromClusterAttributes(this, 'existing', { clusterName: Fn.importValue(${propsBackend.clusterName}-ExistingClusterStackName), vpc: vpc, securityGroups: [ ec2.SecurityGroup.fromLookup( this, 'ECSInstanceSecurityGroup', Fn.importValue(${propsBackend.clusterName}-ExistingClusterSecurityGroup), ), ], }); Whenever i run the cdk synth or cdk deploy command : i am getting the above error Error: All arguments to look up a security group must be concrete (no Tokens)

Please suggest what needs to be done here.

CDK CLI Version

1.132.0

Framework Version

No response

Node.js Version

17.0.1

OS

Mac

Language

Typescript

Language Version

Typescript(4.2.4)

Other information

Hi Team,

I have an implementation where i need to fetch the existing ECS Cluster details. I have the import values from the VPC and Security Group of another base stack. However, While using the Fn.importValue i am getting an error :

All arguments to look up a security group must be concrete (no Tokens)

Here is my source code ecs.Cluster.fromClusterAttributes(this, 'existing', { clusterName: Fn.importValue(${propsBackend.clusterName}-ExistingClusterStackName), vpc: vpc, securityGroups: [ ec2.SecurityGroup.fromLookup( this, 'ECSInstanceSecurityGroup', Fn.importValue(${propsBackend.clusterName}-ExistingClusterSecurityGroup), ), ], });

Whenever i run the cdk synth or cdk deploy command : i am getting the above error Error: All arguments to look up a security group must be concrete (no Tokens)

Please suggest what needs to be done here.

[ryparker]

You can use the aws-sdk-js-v3 which has first-class Typescript support.

I was wondering if there is any patterns already to configure this fix. Because i believe there will be many use cases where Cloudformation outputs needs to be configured and storing them in ID’s in SSM is an overhead according to me.

I don’t have any examples to reference but I can whip up some prototype projects for you. I’ll follow up with you in this thread.

⚠️ One thing to keep in mind is that you cannot await in Typescript class constructs.

Options:

• Fetch the data before initializing any CDK constructs.
• Add a custom method to the stack class that fetches the data, then add the remaining data-dependent resources to the stack.

[aritranagnordcloud]

Wow. This works like charm! You are awesome!