How to get the long region name with AWS CDK

Question

How can one get the region name in AWS CDK?

Some SDKs provide Region objects (see also this question)

Inside a CDK construct, self.region is available, and cdk.aws_region has a RegionInfo class, but it doesn't provide the name, eg: ap-southeast-1 -> Singapore

If it was available in CDK I think you'd find it in https://github.com/aws/aws-cdk/blob/master/packages/%40aws-cdk/region-info/lib/aws-entities.ts - it's not there right now but it looks to be a fairly simple addition — Elliveny, May 17 '22 at 04:51

score 4 · Accepted Answer · edited May 18 '22 at 00:06

AWS exposes region long names (like Asia Pacific (Singapore) for ap-southeast-1) as publicly available Parameter Store parameters. Lookup this value at synth-time with ssm.StringParameter.valueFromLookup^*. You need the region id for the parameter path, which a stack (or construct) can introspect.

export class MyStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props: cdk.StackProps) {
    super(scope, id, props);

    const regionLongName: string = ssm.StringParameter.valueFromLookup(
      this,
      `/aws/service/global-infrastructure/regions/${this.region}/longName`
    );

    console.dir({ region: this.region, regionLongName });
  }
}

For Python

aws_cdk.aws_ssm.StringParameter.value_from_lookup(
            scope=self,
            parameter_name=f'/aws/service/global-infrastructure/regions/{self.region}/longName')

cdk synth output::

{ region: 'us-east-1', regionLongName: 'US East (N. Virginia)' }

* The CDK's valueFromLookup context method will cache the looked-up parameter store value in cdk.context.json at synth-time. You may initially get a dummy value. Just synth again.

How to get the long region name with AWS CDK

1 Answers1