Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Sending Events to CloudWatch

CloudWatch Events delivers a near real-time stream of system events that describe changes in Amazon resources to Amazon EC2 instances, Lambda functions, Kinesis streams, Amazon ECS tasks, Step Functions state machines, Amazon SNS topics, Amazon SQS queues, or built-in targets. You can match events and route them to one or more target functions or streams by using simple rules.

Add Events

To add custom CloudWatch events, call the CloudWatchEventsClient’s PutEvents function with a PutEventsRequest object that contains one or more PutEventsRequestEntry objects that provide details about each event. You can specify several parameters for the entry such as the source and type of the event, resources associated with the event, and so on.

Includes

#include <aws/core/Aws.h>
#include <aws/events/EventBridgeClient.h>
#include <aws/events/model/PutEventsRequest.h>
#include <aws/events/model/PutEventsResult.h>
#include <aws/core/utils/Outcome.h>
#include <iostream>

Code

        Aws::CloudWatchEvents::EventBridgeClient cwe;

        Aws::CloudWatchEvents::Model::PutEventsRequestEntry event_entry;
        event_entry.SetDetail(MakeDetails(event_key, event_value));
        event_entry.SetDetailType("sampleSubmitted");
        event_entry.AddResources(resource_arn);
        event_entry.SetSource("aws-sdk-cpp-cloudwatch-example");

        Aws::CloudWatchEvents::Model::PutEventsRequest request;
        request.AddEntries(event_entry);

        auto outcome = cwe.PutEvents(request);
        if (!outcome.IsSuccess())
        {
            std::cout << "Failed to post CloudWatch event: " <<
                outcome.GetError().GetMessage() << std::endl;
        }
        else
        {
            std::cout << "Successfully posted CloudWatch event" << std::endl;
        }

Add Rules

To create or update a rule, call the CloudWatchEventsClient’s PutRule function with a PutRuleRequest with the name of the rule and optional parameters such as the event pattern, IAM role to associate with the rule, and a scheduling expression that describes how often the rule is run.

Includes

#include <aws/core/Aws.h>
#include <aws/events/EventBridgeClient.h>
#include <aws/events/model/PutRuleRequest.h>
#include <aws/events/model/PutRuleResult.h>
#include <aws/core/utils/Outcome.h>
#include <iostream>

Code

        Aws::CloudWatchEvents::EventBridgeClient cwe;
        Aws::CloudWatchEvents::Model::PutRuleRequest request;
        request.SetName(rule_name);
        request.SetRoleArn(role_arn);
        request.SetScheduleExpression("rate(5 minutes)");
        request.SetState(Aws::CloudWatchEvents::Model::RuleState::ENABLED);

        auto outcome = cwe.PutRule(request);
        if (!outcome.IsSuccess())
        {
            std::cout << "Failed to create CloudWatch events rule " <<
                rule_name << ": " << outcome.GetError().GetMessage() <<
                std::endl;
        }
        else
        {
            std::cout << "Successfully created CloudWatch events rule " <<
                rule_name << " with resulting Arn " <<
                outcome.GetResult().GetRuleArn() << std::endl;
        }

Add Targets

Targets are the resources that are invoked when a rule is triggered. Example targets include Amazon EC2 instances, Lambda functions, Kinesis streams, Amazon ECS tasks, Step Functions state machines, and built-in targets.

To add a target to a rule, call the CloudWatchEventsClient’s PutTargets function with a PutTargetsRequest containing the rule to update and a list of targets to add to the rule.

Includes

#include <aws/core/Aws.h>
#include <aws/events/EventBridgeClient.h>
#include <aws/events/model/PutTargetsRequest.h>
#include <aws/events/model/PutTargetsResult.h>
#include <aws/core/utils/Outcome.h>
#include <iostream>

Code

        Aws::CloudWatchEvents::EventBridgeClient cwe;

        Aws::CloudWatchEvents::Model::Target target;
        target.SetArn(lambda_arn);
        target.SetId(target_id);

        Aws::CloudWatchEvents::Model::PutTargetsRequest request;
        request.SetRule(rule_name);
        request.AddTargets(target);

        auto putTargetsOutcome = cwe.PutTargets(request);
        if (!putTargetsOutcome.IsSuccess())
        {
            std::cout << "Failed to create CloudWatch events target for rule "
                << rule_name << ": " <<
                putTargetsOutcome.GetError().GetMessage() << std::endl;
        }
        else
        {
            std::cout <<
                "Successfully created CloudWatch events target for rule "
                << rule_name << std::endl;
        }

See the complete example.

More Information