Use case

You want to use AWS Cloudwatch Application Signals Transaction Search and your IaC is based on AWS CDK.

Setup

This is how the Transaction Search page looks like, if it's not yet configured:

And like this in the x-ray settings:

The AWS documentation outlines the steps to enable Transaction Search functionality here: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Transaction-Search-getting-started.html#w24aac24c21c13b9

While the documentation provides AWS CLI commands, we can implement the same configuration using AWS CDK Custom Resources for infrastructure as code.

The whole configuration looks like this:

    const { account, region } = Stack.of(this);

      // https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Transaction-Search-getting-started.html#w24aac24c21c13b9
      const applicationSignalsTransactionSearchLogsResourcePolicy =
        new AwsCustomResource(
          this,
          "ApplicationSignalsTransactionSearchLogsResourcePolicy",
          {
            onCreate: {
              service: "@aws-sdk/client-cloudwatch-logs",
              action: "PutResourcePolicy",
              parameters: {
                policyName:
                  "ApplicationSignalsTransactionSearchLogsResourcePolicy",
                policyDocument: JSON.stringify({
                  Version: "2012-10-17",
                  Statement: [
                    {
                      Sid: "TransactionSearchXRayAccess",
                      Effect: "Allow",
                      Principal: {
                        Service: "xray.amazonaws.com",
                      },
                      Action: ["logs:PutLogEvents", "logs:CreateLogStream"],
                      Resource: [
                        `arn:aws:logs:${region}:${account}:log-group:aws/spans:*`,
                        `arn:aws:logs:${region}:${account}:log-group:/aws/application-signals/data:*`,
                      ],
                      Condition: {
                        ArnLike: {
                          "aws:SourceArn": `arn:aws:xray:${region}:${account}:*`,
                        },
                        StringEquals: {
                          "aws:SourceAccount": account,
                        },
                      },
                    },
                  ],
                }),
              },
              physicalResourceId: PhysicalResourceId.of(
                "ApplicationSignalsTransactionSearchLogsResourcePolicy",
              ),
            },
            policy: AwsCustomResourcePolicy.fromSdkCalls({
              resources: AwsCustomResourcePolicy.ANY_RESOURCE,
            }),
          },
        );
      const applicationSignalsTransactionSearchXraySegmentDestination =
        new AwsCustomResource(
          this,
          "ApplicationSignalsTransactionSearchXraySegmentDestination",
          {
            onCreate: {
              service: "@aws-sdk/client-xray",
              action: "UpdateTraceSegmentDestination",
              parameters: {
                Destination: "CloudWatchLogs",
              },
              physicalResourceId: PhysicalResourceId.of(
                "ApplicationSignalsTransactionSearchXraySegmentDestination",
              ),
            },
            installLatestAwsSdk: true,
            policy: AwsCustomResourcePolicy.fromStatements([
              new PolicyStatement({
                effect: Effect.ALLOW,
                actions: ["logs:PutRetentionPolicy"],
                resources: [
                  `arn:aws:logs:${region}:${account}:log-group:aws/spans:log-stream:`,
                ],
              }),
              new PolicyStatement({
                effect: Effect.ALLOW,
                actions: ["xray:UpdateTraceSegmentDestination"],
                resources: ["*"],
              }),
            ]),
          },
        );
      applicationSignalsTransactionSearchXraySegmentDestination.node.addDependency(
        applicationSignalsTransactionSearchLogsResourcePolicy,
      );
      const applicationSignalsTransactionSearchXrayIndexRule =
        new AwsCustomResource(
          this,
          "ApplicationSignalsTransactionSearchXrayIndexRule",
          {
            onCreate: {
              service: "@aws-sdk/client-xray",
              action: "UpdateIndexingRule",
              parameters: {
                Name: "Default",
                Rule: {
                  Probabilistic: {
                    DesiredSamplingPercentage: 100,
                  },
                },
              },
              physicalResourceId: PhysicalResourceId.of(
                "ApplicationSignalsTransactionSearchXrayIndexRule",
              ),
            },
            installLatestAwsSdk: true,
            policy: AwsCustomResourcePolicy.fromSdkCalls({
              resources: AwsCustomResourcePolicy.ANY_RESOURCE,
            }),
          },
        );
      NagSuppressions.addResourceSuppressions(
        [
          applicationSignalsTransactionSearchXraySegmentDestination,
          applicationSignalsTransactionSearchLogsResourcePolicy,
          applicationSignalsTransactionSearchXrayIndexRule,
        ],
        [
          {
            id: "AwsSolutions-IAM5",
            reason: "CDK managed policy",
          },
        ],
        true,
      );
    }

It contains the following steps:

Update the Cloudwatch Logs Resource Policy
Update the x-ray settings

Update the Cloudwatch Logs Resource Policy

The documentation here is a little bit misleading. The shown condition arn:partition:logs:region:account-id:* should be arn:partition:xray:region:account-id:*. Also the action logs:PutLogEvents should be logs:PutLogEvents and logs:CreateLogStream.

 const applicationSignalsTransactionSearchLogsResourcePolicy =
        new AwsCustomResource(
          this,
          "ApplicationSignalsTransactionSearchLogsResourcePolicy",
          {
            onCreate: {
              service: "@aws-sdk/client-cloudwatch-logs",
              action: "PutResourcePolicy",
              parameters: {
                policyName:
                  "ApplicationSignalsTransactionSearchLogsResourcePolicy",
                policyDocument: JSON.stringify({
                  Version: "2012-10-17",
                  Statement: [
                    {
                      Sid: "TransactionSearchXRayAccess",
                      Effect: "Allow",
                      Principal: {
                        Service: "xray.amazonaws.com",
                      },
                      Action: ["logs:PutLogEvents", "logs:CreateLogStream"],
                      Resource: [
                        `arn:aws:logs:${region}:${account}:log-group:aws/spans:*`,
                        `arn:aws:logs:${region}:${account}:log-group:/aws/application-signals/data:*`,
                      ],
                      Condition: {
                        ArnLike: {
                          "aws:SourceArn": `arn:aws:xray:${region}:${account}:*`,
                        },
                        StringEquals: {
                          "aws:SourceAccount": account,
                        },
                      },
                    },
                  ],
                }),
              },
              physicalResourceId: PhysicalResourceId.of(
                "ApplicationSignalsTransactionSearchLogsResourcePolicy",
              ),
            },
            policy: AwsCustomResourcePolicy.fromSdkCalls({
              resources: AwsCustomResourcePolicy.ANY_RESOURCE,
            }),
          },
        );

Update the x-ray settings

The 2 API calls for x-ray are nearly straight forward. Only the comamnds UpdateTraceSegmentDestination and UpdateIndexingRule requires the newest SDK version, because it's introduced in version: https://github.com/aws/aws-sdk-js-v3/releases/tag/v3.698.0

 const applicationSignalsTransactionSearchXraySegmentDestination =
        new AwsCustomResource(
          this,
          "ApplicationSignalsTransactionSearchXraySegmentDestination",
          {
            onCreate: {
              service: "@aws-sdk/client-xray",
              action: "UpdateTraceSegmentDestination",
              parameters: {
                Destination: "CloudWatchLogs",
              },
              physicalResourceId: PhysicalResourceId.of(
                "ApplicationSignalsTransactionSearchXraySegmentDestination",
              ),
            },
            installLatestAwsSdk: true,
            policy: AwsCustomResourcePolicy.fromStatements([
              new PolicyStatement({
                effect: Effect.ALLOW,
                actions: ["logs:PutRetentionPolicy"],
                resources: [
                  `arn:aws:logs:${region}:${account}:log-group:aws/spans:log-stream:`,
                ],
              }),
              new PolicyStatement({
                effect: Effect.ALLOW,
                actions: ["xray:UpdateTraceSegmentDestination"],
                resources: ["*"],
              }),
            ]),
          },
        );
      applicationSignalsTransactionSearchXraySegmentDestination.node.addDependency(
        applicationSignalsTransactionSearchLogsResourcePolicy,
      );
      const applicationSignalsTransactionSearchXrayIndexRule =
        new AwsCustomResource(
          this,
          "ApplicationSignalsTransactionSearchXrayIndexRule",
          {
            onCreate: {
              service: "@aws-sdk/client-xray",
              action: "UpdateIndexingRule",
              parameters: {
                Name: "Default",
                Rule: {
                  Probabilistic: {
                    DesiredSamplingPercentage: 100,
                  },
                },
              },
              physicalResourceId: PhysicalResourceId.of(
                "ApplicationSignalsTransactionSearchXrayIndexRule",
              ),
            },
            installLatestAwsSdk: true,
            policy: AwsCustomResourcePolicy.fromSdkCalls({
              resources: AwsCustomResourcePolicy.ANY_RESOURCE,
            }),
          },
        );

Result

After some minutes the Transaction Search is visible in the Management Console.

Config AWS Cloudwatch Application Signals Transaction Search with CDK

Use case

Setup

Update the Cloudwatch Logs Resource Policy

Update the x-ray settings

Result