Use ListMetrics with an Amazon SDK or CLI

    /// <summary>
    /// List metrics available, optionally within a namespace.
    /// </summary>
    /// <param name="metricNamespace">Optional CloudWatch namespace to use when listing metrics.</param>
    /// <param name="filter">Optional dimension filter.</param>
    /// <param name="metricName">Optional metric name filter.</param>
    /// <returns>The list of metrics.</returns>
    public async Task<List<Metric>> ListMetrics(string? metricNamespace = null, DimensionFilter? filter = null, string? metricName = null)
    {
        var results = new List<Metric>();
        var paginateMetrics = _amazonCloudWatch.Paginators.ListMetrics(
            new ListMetricsRequest
            {
                Namespace = metricNamespace,
                Dimensions = filter != null ? new List<DimensionFilter> { filter } : null,
                MetricName = metricName
            });
        // Get the entire list using the paginator.
        await foreach (var metric in paginateMetrics.Metrics)
        {
            results.Add(metric);
        }

        return results;
    }

Include the required files.

#include <aws/core/Aws.h>
#include <aws/monitoring/CloudWatchClient.h>
#include <aws/monitoring/model/ListMetricsRequest.h>
#include <aws/monitoring/model/ListMetricsResult.h>
#include <iomanip>
#include <iostream>

List the metrics.

        Aws::CloudWatch::CloudWatchClient cw;
        Aws::CloudWatch::Model::ListMetricsRequest request;

        if (argc > 1)
        {
            request.SetMetricName(argv[1]);
        }

        if (argc > 2)
        {
            request.SetNamespace(argv[2]);
        }

        bool done = false;
        bool header = false;
        while (!done)
        {
            auto outcome = cw.ListMetrics(request);
            if (!outcome.IsSuccess())
            {
                std::cout << "Failed to list CloudWatch metrics:" <<
                    outcome.GetError().GetMessage() << std::endl;
                break;
            }

            if (!header)
            {
                std::cout << std::left << std::setw(48) << "MetricName" <<
                    std::setw(32) << "Namespace" << "DimensionNameValuePairs" <<
                    std::endl;
                header = true;
            }

            const auto &metrics = outcome.GetResult().GetMetrics();
            for (const auto &metric : metrics)
            {
                std::cout << std::left << std::setw(48) <<
                    metric.GetMetricName() << std::setw(32) <<
                    metric.GetNamespace();
                const auto &dimensions = metric.GetDimensions();
                for (auto iter = dimensions.cbegin();
                    iter != dimensions.cend(); ++iter)
                {
                    const auto &dimkv = *iter;
                    std::cout << dimkv.GetName() << " = " << dimkv.GetValue();
                    if (iter + 1 != dimensions.cend())
                    {
                        std::cout << ", ";
                    }
                }
                std::cout << std::endl;
            }

            const auto &next_token = outcome.GetResult().GetNextToken();
            request.SetNextToken(next_token);
            done = next_token.empty();
        }

To list the metrics for Amazon SNS

The following list-metrics example displays the metrics for Amazon SNS.

aws cloudwatch list-metrics \
    --namespace "AWS/SNS"

Output:

{
    "Metrics": [
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "NotifyMe"
                }
            ],
            "MetricName": "PublishSize"
        },
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "CFO"
                }
            ],
            "MetricName": "PublishSize"
        },
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "NotifyMe"
                }
            ],
            "MetricName": "NumberOfNotificationsFailed"
        },
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "NotifyMe"
                }
            ],
            "MetricName": "NumberOfNotificationsDelivered"
        },
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "NotifyMe"
                }
            ],
            "MetricName": "NumberOfMessagesPublished"
        },
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "CFO"
                }
            ],
            "MetricName": "NumberOfMessagesPublished"
        },
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "CFO"
                }
            ],
            "MetricName": "NumberOfNotificationsDelivered"
        },
        {
            "Namespace": "AWS/SNS",
            "Dimensions": [
                {
                    "Name": "TopicName",
                    "Value": "CFO"
                }
            ],
            "MetricName": "NumberOfNotificationsFailed"
        }
    ]
}

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatch.CloudWatchClient;
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException;
import software.amazon.awssdk.services.cloudwatch.model.ListMetricsRequest;
import software.amazon.awssdk.services.cloudwatch.model.ListMetricsResponse;
import software.amazon.awssdk.services.cloudwatch.model.Metric;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class ListMetrics {
    public static void main(String[] args) {
        final String usage = """

                Usage:
                  <namespace>\s

                Where:
                  namespace - The namespace to filter against (for example, AWS/EC2).\s
                """;

        if (args.length != 1) {
            System.out.println(usage);
            System.exit(1);
        }

        String namespace = args[0];
        Region region = Region.US_EAST_1;
        CloudWatchClient cw = CloudWatchClient.builder()
                .region(region)
                .build();

        listMets(cw, namespace);
        cw.close();
    }

    public static void listMets(CloudWatchClient cw, String namespace) {
        boolean done = false;
        String nextToken = null;

        try {
            while (!done) {

                ListMetricsResponse response;
                if (nextToken == null) {
                    ListMetricsRequest request = ListMetricsRequest.builder()
                            .namespace(namespace)
                            .build();

                    response = cw.listMetrics(request);
                } else {
                    ListMetricsRequest request = ListMetricsRequest.builder()
                            .namespace(namespace)
                            .nextToken(nextToken)
                            .build();

                    response = cw.listMetrics(request);
                }

                for (Metric metric : response.metrics()) {
                    System.out.printf("Retrieved metric %s", metric.metricName());
                    System.out.println();
                }

                if (response.nextToken() == null) {
                    done = true;
                } else {
                    nextToken = response.nextToken();
                }
            }

        } catch (CloudWatchException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
}

Import the SDK and client modules and call the API.

import { ListMetricsCommand } from "@aws-sdk/client-cloudwatch";
import { client } from "../libs/client.js";

export const main = () => {
  // Use the AWS console to see available namespaces and metric names. Custom metrics can also be created.
  // https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/viewing_metrics_with_cloudwatch.html
  const command = new ListMetricsCommand({
    Dimensions: [
      {
        Name: "LogGroupName",
      },
    ],
    MetricName: "IncomingLogEvents",
    Namespace: "AWS/Logs",
  });

  return client.send(command);
};

Create the client in a separate module and export it.

import { CloudWatchClient } from "@aws-sdk/client-cloudwatch";

export const client = new CloudWatchClient({});

// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });

// Create CloudWatch service object
var cw = new AWS.CloudWatch({ apiVersion: "2010-08-01" });

var params = {
  Dimensions: [
    {
      Name: "LogGroupName" /* required */,
    },
  ],
  MetricName: "IncomingLogEvents",
  Namespace: "AWS/Logs",
};

cw.listMetrics(params, function (err, data) {
  if (err) {
    console.log("Error", err);
  } else {
    console.log("Metrics", JSON.stringify(data.Metrics));
  }
});

suspend fun listMets(namespaceVal: String?): ArrayList<String>? {
    val metList = ArrayList<String>()
    val request =
        ListMetricsRequest {
            namespace = namespaceVal
        }
    CloudWatchClient { region = "us-east-1" }.use { cwClient ->
        val reponse = cwClient.listMetrics(request)
        reponse.metrics?.forEach { metrics ->
            val data = metrics.metricName
            if (!metList.contains(data)) {
                metList.add(data!!)
            }
        }
    }
    return metList
}

class CloudWatchWrapper:
    """Encapsulates Amazon CloudWatch functions."""

    def __init__(self, cloudwatch_resource):
        """
        :param cloudwatch_resource: A Boto3 CloudWatch resource.
        """
        self.cloudwatch_resource = cloudwatch_resource


    def list_metrics(self, namespace, name, recent=False):
        """
        Gets the metrics within a namespace that have the specified name.
        If the metric has no dimensions, a single metric is returned.
        Otherwise, metrics for all dimensions are returned.

        :param namespace: The namespace of the metric.
        :param name: The name of the metric.
        :param recent: When True, only metrics that have been active in the last
                       three hours are returned.
        :return: An iterator that yields the retrieved metrics.
        """
        try:
            kwargs = {"Namespace": namespace, "MetricName": name}
            if recent:
                kwargs["RecentlyActive"] = "PT3H"  # List past 3 hours only
            metric_iter = self.cloudwatch_resource.metrics.filter(**kwargs)
            logger.info("Got metrics for %s.%s.", namespace, name)
        except ClientError:
            logger.exception("Couldn't get metrics for %s.%s.", namespace, name)
            raise
        else:
            return metric_iter

# Lists available metrics for a metric namespace in Amazon CloudWatch.
#
# @param cloudwatch_client [Aws::CloudWatch::Client]
#   An initialized CloudWatch client.
# @param metric_namespace [String] The namespace of the metric.
# @example
#   list_metrics_for_namespace(
#     Aws::CloudWatch::Client.new(region: 'us-east-1'),
#     'SITE/TRAFFIC'
#   )
def list_metrics_for_namespace(cloudwatch_client, metric_namespace)
  response = cloudwatch_client.list_metrics(namespace: metric_namespace)

  if response.metrics.count.positive?
    response.metrics.each do |metric|
      puts "  Metric name: #{metric.metric_name}"
      if metric.dimensions.count.positive?
        puts "    Dimensions:"
        metric.dimensions.each do |dimension|
          puts "      Name: #{dimension.name}, Value: #{dimension.value}"
        end
      else
        puts "No dimensions found."
      end
    end
  else
    puts "No metrics found for namespace '#{metric_namespace}'. " \
      "Note that it could take up to 15 minutes for recently-added metrics " \
      "to become available."
  end
end

# Example usage:
def run_me
  metric_namespace = "SITE/TRAFFIC"
  # Replace us-west-2 with the AWS Region you're using for Amazon CloudWatch.
  region = "us-east-1"

  cloudwatch_client = Aws::CloudWatch::Client.new(region: region)

  # Add three datapoints.
  puts "Continuing..." unless datapoint_added_to_metric?(
    cloudwatch_client,
    metric_namespace,
    "UniqueVisitors",
    "SiteName",
    "example.com",
    5_885.0,
    "Count"
  )

  puts "Continuing..." unless datapoint_added_to_metric?(
    cloudwatch_client,
    metric_namespace,
    "UniqueVisits",
    "SiteName",
    "example.com",
    8_628.0,
    "Count"
  )

  puts "Continuing..." unless datapoint_added_to_metric?(
    cloudwatch_client,
    metric_namespace,
    "PageViews",
    "PageURL",
    "example.html",
    18_057.0,
    "Count"
  )

  puts "Metrics for namespace '#{metric_namespace}':"
  list_metrics_for_namespace(cloudwatch_client, metric_namespace)
end

run_me if $PROGRAM_NAME == __FILE__

    "The following list-metrics example displays the metrics for Amazon CloudWatch."
    TRY.
        oo_result = lo_cwt->listmetrics(            " oo_result is returned for testing purposes. "
          iv_namespace = iv_namespace
        ).
        DATA(lt_metrics) = oo_result->get_metrics( ).
        MESSAGE 'Metrics retrieved.' TYPE 'I'.
      CATCH /aws1/cx_cwtinvparamvalueex .
        MESSAGE 'The specified argument was not valid.' TYPE 'E'.
    ENDTRY.