AWS CDK でパラメーターストアをクロスリージョンで取得するカスタムリソースを作ってみた

import { custom_resources } from 'aws-cdk-lib';
import { Construct } from 'constructs';

export class CrossRegionGetParameter extends Construct {
  public readonly parameterValue: string;

  constructor(
    scope: Construct,
    id: string,
    props: {
      readonly parameterName: string;
      readonly region: string;
    }
  ) {
    super(scope, id);

    const getParameter = new custom_resources.AwsCustomResource(
      this,
      'GetParameterCustomResource',
      {
        onUpdate: {
          service: 'SSM',
          action: 'getParameter',
          parameters: {
            Name: props.parameterName,
          },
          physicalResourceId: custom_resources.PhysicalResourceId.of(
            props.parameterName
          ),
          region: props.region,
        },
        policy: custom_resources.AwsCustomResourcePolicy.fromSdkCalls({
          resources: custom_resources.AwsCustomResourcePolicy.ANY_RESOURCE,
        }),
        installLatestAwsSdk: false,
      }
    );

    this.parameterValue = getParameter.getResponseField('Parameter.Value');
  }
}

aws ssm put-parameter --name sampleVirginiaParameter --type String --value "Hello from Virginia" --region us-east-1

import { Stack, CfnOutput } from 'aws-cdk-lib';
import { Construct } from 'constructs';

import { CrossRegionGetParameter } from './cross-region-get-parameter-custom-resource';

export class CdkSampleStack extends Stack {
  constructor(scope: Construct, id: string) {
    super(scope, id);

    // カスタムリソースを使って、us-east-1 リージョンのパラメータストアを取得する
    const sampleVirginiaParameter = new CrossRegionGetParameter(
      this,
      'SampleVirginiaParameter',
      {
        parameterName: 'sampleVirginiaParameter',
        region: 'us-east-1',
      }
    );

    // 取得したパラメータの値を確認
    new CfnOutput(this, 'SampleVirginiaParameterValueOutput', {
      value: sampleVirginiaParameter.parameterValue,
    });
  }
}

$ npm run deploy

> cdk_sample_app@0.1.0 deploy
> cdk deploy --require-approval never --method=direct

✨  Synthesis time: 2.93s

CdkSampleStack:  start: Building e4ea0253cc86c2c55a7b1f7ed734d91c8db2f5e8f8477c3a5a01690557a76c01:current_account-current_region
CdkSampleStack:  success: Built e4ea0253cc86c2c55a7b1f7ed734d91c8db2f5e8f8477c3a5a01690557a76c01:current_account-current_region
CdkSampleStack:  start: Publishing e4ea0253cc86c2c55a7b1f7ed734d91c8db2f5e8f8477c3a5a01690557a76c01:current_account-current_region
CdkSampleStack:  success: Published e4ea0253cc86c2c55a7b1f7ed734d91c8db2f5e8f8477c3a5a01690557a76c01:current_account-current_region
CdkSampleStack: deploying... [1/1]
CdkSampleStack: updating stack...

 ✅  CdkSampleStack

✨  Deployment time: 11.61s

Outputs:
CdkSampleStack.SampleVirginiaParameterValueOutput = Hello from Virginia
Stack ARN:
arn:aws:cloudformation:ap-northeast-1:XXXXXXXXXXXX:stack/CdkSampleStack/bdcdf7a0-3443-11ef-8401-06d40bdb5af9

✨  Total time: 14.54s

npm run deploy

> cdk_sample_app@0.1.0 deploy
> cdk deploy --require-approval never --method=direct

[Warning at /CdkSampleStack/SampleVirginiaParameter/GetParameterCustomResource] installLatestAwsSdk was not specified, and defaults to true. You probably do not want this. Set the global context flag '@aws-cdk/customresources:installLatestAwsSdkDefault' to false to switch this behavior off project-wide, or set the property explicitly to true if you know you need to call APIs that are not in Lambda's built-in SDK version. [ack: @aws-cdk/custom-resources:installLatestAwsSdkNotSpecified]

✨  Synthesis time: 3.16s