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Package software.amazon.awscdk.services.events.targets

Event Targets for Amazon EventBridge

See: Description

Package software.amazon.awscdk.services.events.targets Description

Event Targets for Amazon EventBridge

This library contains integration classes to send Amazon EventBridge to any number of supported AWS Services. Instances of these classes should be passed to the rule.addTarget() method.

Currently supported are:

See the README of the @aws-cdk/aws-events library for more information on EventBridge.

Event retry policy and using dead-letter queues

The Codebuild, CodePipeline, Lambda, StepFunctions, LogGroup, SQSQueue, SNSTopic and ECSTask targets support attaching a dead letter queue and setting retry policies. See the lambda example. Use escape hatches for the other target types.

Invoke a Lambda function

Use the LambdaFunction target to invoke a lambda function.

The code snippet below creates an event rule with a Lambda function as a target triggered for every events from aws.ec2 source. You can optionally attach a dead letter queue. 

 import software.amazon.awscdk.services.lambda.*;
 
 
 Function fn = Function.Builder.create(this, "MyFunc")
         .runtime(Runtime.NODEJS_14_X)
         .handler("index.handler")
         .code(Code.fromInline("exports.handler = handler.toString()"))
         .build();
 
 Rule rule = Rule.Builder.create(this, "rule")
         .eventPattern(EventPattern.builder()
                 .source(List.of("aws.ec2"))
                 .build())
         .build();
 
 Queue queue = new Queue(this, "Queue");
 
 rule.addTarget(LambdaFunction.Builder.create(fn)
         .deadLetterQueue(queue) // Optional: add a dead letter queue
         .maxEventAge(Duration.hours(2)) // Optional: set the maxEventAge retry policy
         .retryAttempts(2)
         .build());

Log an event into a LogGroup

Use the LogGroup target to log your events in a CloudWatch LogGroup.

For example, the following code snippet creates an event rule with a CloudWatch LogGroup as a target. Every events sent from the aws.ec2 source will be sent to the CloudWatch LogGroup. 

 import software.amazon.awscdk.services.logs.*;
 
 
 LogGroup logGroup = LogGroup.Builder.create(this, "MyLogGroup")
         .logGroupName("MyLogGroup")
         .build();
 
 Rule rule = Rule.Builder.create(this, "rule")
         .eventPattern(EventPattern.builder()
                 .source(List.of("aws.ec2"))
                 .build())
         .build();
 
 rule.addTarget(new CloudWatchLogGroup(logGroup));

A rule target input can also be specified to modify the event that is sent to the log group. Unlike other event targets, CloudWatchLogs requires a specific input template format. 

 // Example automatically generated from non-compiling source. May contain errors.
 import software.amazon.awscdk.services.logs.*;
 LogGroup logGroup;
 Rule rule;
 
 
 rule.addTarget(CloudWatchLogGroup.Builder.create(logGroup)
         .logEvent(LogGroupTargetInput(Map.of(
                 "timestamp", EventField.from("$.time"),
                 "message", EventField.from("$.detail-type"))))
         .build());

If you want to use static values to overwrite the message make sure that you provide a string value. 

 // Example automatically generated from non-compiling source. May contain errors.
 import software.amazon.awscdk.services.logs.*;
 LogGroup logGroup;
 Rule rule;
 
 
 rule.addTarget(CloudWatchLogGroup.Builder.create(logGroup)
         .logEvent(LogGroupTargetInput(Map.of(
                 "message", JSON.stringify(Map.of(
                         "CustomField", "CustomValue")))))
         .build());

Start a CodeBuild build

Use the CodeBuildProject target to trigger a CodeBuild project.

The code snippet below creates a CodeCommit repository that triggers a CodeBuild project on commit to the master branch. You can optionally attach a dead letter queue. 

 import software.amazon.awscdk.services.codebuild.*;
 import software.amazon.awscdk.services.codecommit.*;
 
 
 Repository repo = Repository.Builder.create(this, "MyRepo")
         .repositoryName("aws-cdk-codebuild-events")
         .build();
 
 Project project = Project.Builder.create(this, "MyProject")
         .source(Source.codeCommit(CodeCommitSourceProps.builder().repository(repo).build()))
         .build();
 
 Queue deadLetterQueue = new Queue(this, "DeadLetterQueue");
 
 // trigger a build when a commit is pushed to the repo
 Rule onCommitRule = repo.onCommit("OnCommit", OnCommitOptions.builder()
         .target(CodeBuildProject.Builder.create(project)
                 .deadLetterQueue(deadLetterQueue)
                 .build())
         .branches(List.of("master"))
         .build());

Start a CodePipeline pipeline

Use the CodePipeline target to trigger a CodePipeline pipeline.

The code snippet below creates a CodePipeline pipeline that is triggered every hour 

 import software.amazon.awscdk.services.codepipeline.*;
 
 
 Pipeline pipeline = new Pipeline(this, "Pipeline");
 
 Rule rule = Rule.Builder.create(this, "Rule")
         .schedule(Schedule.expression("rate(1 hour)"))
         .build();
 
 rule.addTarget(new CodePipeline(pipeline));

Start a StepFunctions state machine

Use the SfnStateMachine target to trigger a State Machine.

The code snippet below creates a Simple StateMachine that is triggered every minute with a dummy object as input. You can optionally attach a dead letter queue to the target. 

 import software.amazon.awscdk.services.iam.*;
 import software.amazon.awscdk.services.stepfunctions.*;
 
 
 Rule rule = Rule.Builder.create(this, "Rule")
         .schedule(Schedule.rate(Duration.minutes(1)))
         .build();
 
 Queue dlq = new Queue(this, "DeadLetterQueue");
 
 Role role = Role.Builder.create(this, "Role")
         .assumedBy(new ServicePrincipal("events.amazonaws.com"))
         .build();
 StateMachine stateMachine = StateMachine.Builder.create(this, "SM")
         .definition(Wait.Builder.create(this, "Hello").time(WaitTime.duration(Duration.seconds(10))).build())
         .build();
 
 rule.addTarget(SfnStateMachine.Builder.create(stateMachine)
         .input(RuleTargetInput.fromObject(Map.of("SomeParam", "SomeValue")))
         .deadLetterQueue(dlq)
         .role(role)
         .build());

Queue a Batch job

Use the BatchJob target to queue a Batch job.

The code snippet below creates a Simple JobQueue that is triggered every hour with a dummy object as input. You can optionally attach a dead letter queue to the target. 

 // Example automatically generated from non-compiling source. May contain errors.
 import software.amazon.awscdk.services.batch.*;
 import software.amazon.awscdk.services.ecs.ContainerImage;
 
 
 Object jobQueue = JobQueue.Builder.create(this, "MyQueue")
         .computeEnvironments(List.of(Map.of(
                 "computeEnvironment", ComputeEnvironment.Builder.create(this, "ComputeEnvironment")
                         .managed(false)
                         .build(),
                 "order", 1)))
         .build();
 
 Object jobDefinition = JobDefinition.Builder.create(this, "MyJob")
         .container(Map.of(
                 "image", ContainerImage.fromRegistry("test-repo")))
         .build();
 
 Queue queue = new Queue(this, "Queue");
 
 Rule rule = Rule.Builder.create(this, "Rule")
         .schedule(Schedule.rate(Duration.hours(1)))
         .build();
 
 rule.addTarget(BatchJob.Builder.create(jobQueue.getJobQueueArn(), jobQueue, jobDefinition.getJobDefinitionArn(), jobDefinition)
         .deadLetterQueue(queue)
         .event(RuleTargetInput.fromObject(Map.of("SomeParam", "SomeValue")))
         .retryAttempts(2)
         .maxEventAge(Duration.hours(2))
         .build());

Invoke an API Gateway REST API

Use the ApiGateway target to trigger a REST API.

The code snippet below creates a Api Gateway REST API that is invoked every hour. 

 import software.amazon.awscdk.services.apigateway.*;
 import software.amazon.awscdk.services.lambda.*;
 
 
 Rule rule = Rule.Builder.create(this, "Rule")
         .schedule(Schedule.rate(Duration.minutes(1)))
         .build();
 
 Function fn = Function.Builder.create(this, "MyFunc")
         .handler("index.handler")
         .runtime(Runtime.NODEJS_14_X)
         .code(Code.fromInline("exports.handler = e => {}"))
         .build();
 
 LambdaRestApi restApi = LambdaRestApi.Builder.create(this, "MyRestAPI").handler(fn).build();
 
 Queue dlq = new Queue(this, "DeadLetterQueue");
 
 rule.addTarget(
 ApiGateway.Builder.create(restApi)
         .path("/*/test")
         .method("GET")
         .stage("prod")
         .pathParameterValues(List.of("path-value"))
         .headerParameters(Map.of(
                 "Header1", "header1"))
         .queryStringParameters(Map.of(
                 "QueryParam1", "query-param-1"))
         .deadLetterQueue(dlq)
         .build());

Invoke an API Destination

Use the targets.ApiDestination target to trigger an external API. You need to create an events.Connection and events.ApiDestination as well.

The code snippet below creates an external destination that is invoked every hour. 

 Connection connection = Connection.Builder.create(this, "Connection")
         .authorization(Authorization.apiKey("x-api-key", SecretValue.secretsManager("ApiSecretName")))
         .description("Connection with API Key x-api-key")
         .build();
 
 ApiDestination destination = ApiDestination.Builder.create(this, "Destination")
         .connection(connection)
         .endpoint("https://example.com")
         .description("Calling example.com with API key x-api-key")
         .build();
 
 Rule rule = Rule.Builder.create(this, "Rule")
         .schedule(Schedule.rate(Duration.minutes(1)))
         .targets(List.of(new ApiDestination(destination)))
         .build();

Put an event on an EventBridge bus

Use the EventBus target to route event to a different EventBus.

The code snippet below creates the scheduled event rule that route events to an imported event bus. 

 Rule rule = Rule.Builder.create(this, "Rule")
         .schedule(Schedule.expression("rate(1 minute)"))
         .build();
 
 rule.addTarget(new EventBus(EventBus.fromEventBusArn(this, "External", "arn:aws:events:eu-west-1:999999999999:event-bus/test-bus")));
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