aws-cdk/aws-logs: Cannot add dimensions to MetricFilter

Description

It is possible to add dimensions to a metric filter via the console, but this functionality does not seem to be carried through into CDK.

I expected to be able to add dimensions via metric filter props, but I could only add them to the metric itself and that did not work:

    const metric = new CW.Metric({
      namespace: "demoNs",
      metricName: "demoMetric",
      dimensions: { Type: "$.type" },
    });

    new Logs.MetricFilter(this, `MetricFilter`, {
      metricName: "demoMetric",
      metricNamespace: "demoNs",
      logGroup: props.logGroup,
      filterPattern: Logs.FilterPattern.all(
        Logs.FilterPattern.stringValue("$.category", "==", "metric"),
        Logs.FilterPattern.stringValue("$.name", "==", "success")
      ),
      metricValue: "1",
    });

There is no mention of dimensions at all in the documentation: https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-logs.MetricFilter.html

Use Case

Currently I need to create separate metric filters for each dimension, which is not optimal.

Proposed Solution

    const metric = new CW.Metric({
      namespace: "demoNs",
      metricName: "demoMetric"
    });

    new Logs.MetricFilter(this, `MetricFilter`, {
      metricName: "demoMetric",
      metricNamespace: "demoNs",
      logGroup: props.logGroup,
      filterPattern: Logs.FilterPattern.all(
        Logs.FilterPattern.stringValue("$.category", "==", "metric"),
        Logs.FilterPattern.stringValue("$.name", "==", "success")
      ),
      metricValue: "1",
      dimensions: { Type: "$.type" },
    });

Other information

No response

Acknowledge

• I may be able to implement this feature request
• This feature might incur a breaking change

[marcogrcr]

Until dimension support is added to CloudFormation and CDK, you can use this construct:

import { Construct, Names } from "monocdk";
import {
  ILogGroup,
  MetricFilterOptions,
  RetentionDays,
} from "monocdk/aws-logs";
import {
  AwsCustomResource,
  AwsCustomResourcePolicy,
  AwsSdkCall,
  PhysicalResourceId,
} from "monocdk/custom-resources";

export interface MetricFilterProps extends MetricFilterOptions {
  /** The dimensions of the metric. */
  readonly dimensions?: Record<string, string>;

  /** The log group to add the dimensions to. */
  readonly logGroup: ILogGroup;
}

/**
 * Creates a metric filter on a log group using an AWS custom resource.
 * This construct is temporary until CloudFormation and CDK support metric filter dimensions.
 * @see https://github.com/aws-cloudformation/cloudformation-coverage-roadmap/issues/419
 * @see https://github.com/aws/aws-cdk/issues/16999
 */
export class MetricFilter extends Construct {
  constructor(scope: Construct, id: string, props: MetricFilterProps) {
    super(scope, id);

    const uniqueId = Names.uniqueId(this);

    const onCreateOrUpdate: AwsSdkCall = {
      service: "CloudWatchLogs",
      action: "putMetricFilter",
      physicalResourceId: PhysicalResourceId.of(uniqueId),
      parameters: {
        filterName: uniqueId,
        filterPattern: props.filterPattern.logPatternString,
        logGroupName: props.logGroup.logGroupName,
        metricTransformations: [
          {
            defaultValue: props.defaultValue,
            dimensions: props.dimensions,
            metricName: props.metricName,
            metricNamespace: props.metricNamespace,
            metricValue: props.metricValue ?? "1",
          },
        ],
      },
    };

    const onDelete: AwsSdkCall = {
      service: "CloudWatchLogs",
      action: "deleteMetricFilter",
      parameters: {
        filterName: uniqueId,
        logGroupName: props.logGroup.logGroupName,
      },
    };

    new AwsCustomResource(this, "Default", {
      resourceType: "Custom::MetricFilter",
      onCreate: onCreateOrUpdate,
      onDelete,
      onUpdate: onCreateOrUpdate,
      policy: AwsCustomResourcePolicy.fromSdkCalls({
        resources: AwsCustomResourcePolicy.ANY_RESOURCE,
      }),
      logRetention: RetentionDays.THREE_MONTHS,
    });
  }
}

Example usage:

import { FilterPattern, LogGroup } from "monocdk/aws-logs";

const logGroup = new LogGroup(this, "CloudTrailEvents");

new MetricFilter(this, "MyMetricFilter", {
  dimensions: {
    EventSource: "$.detail.eventSource",
    EventName: "$.detail.eventName"
  },
  filterPattern: FilterPattern.exists("$.detail.eventName"),
  logGroup,
  metricName: "EventCount",
  metricNamespace: "CloudTrailEvents",
  metricValue: "1",
});

[iRoachie]

Thanks @seyeong, i opened a PR to implement this #21654