Event Targets for Amazon EventBridge

---

cdk-constructs: Stable


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 and SQSQueue 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 aws_cdk.aws_lambda as lambda_


fn = lambda_.Function(self, "MyFunc",
    runtime=lambda_.Runtime.NODEJS_12_X,
    handler="index.handler",
    code=lambda_.Code.from_inline("exports.handler = handler.toString()")
)

rule = events.Rule(self, "rule",
    event_pattern=events.EventPattern(
        source=["aws.ec2"]
    )
)

queue = sqs.Queue(self, "Queue")

rule.add_target(targets.LambdaFunction(fn,
    dead_letter_queue=queue,  # Optional: add a dead letter queue
    max_event_age=cdk.Duration.hours(2),  # Optional: set the maxEventAge retry policy
    retry_attempts=2
))

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 aws_cdk.aws_logs as logs


log_group = logs.LogGroup(self, "MyLogGroup",
    log_group_name="MyLogGroup"
)

rule = events.Rule(self, "rule",
    event_pattern=events.EventPattern(
        source=["aws.ec2"]
    )
)

rule.add_target(targets.CloudWatchLogGroup(log_group))

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 aws_cdk.aws_codebuild as codebuild
import aws_cdk.aws_codecommit as codecommit


repo = codecommit.Repository(self, "MyRepo",
    repository_name="aws-cdk-codebuild-events"
)

project = codebuild.Project(self, "MyProject",
    source=codebuild.Source.code_commit(repository=repo)
)

dead_letter_queue = sqs.Queue(self, "DeadLetterQueue")

# trigger a build when a commit is pushed to the repo
on_commit_rule = repo.on_commit("OnCommit",
    target=targets.CodeBuildProject(project,
        dead_letter_queue=dead_letter_queue
    ),
    branches=["master"]
)

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 aws_cdk.aws_codepipeline as codepipeline


pipeline = codepipeline.Pipeline(self, "Pipeline")

rule = events.Rule(self, "Rule",
    schedule=events.Schedule.expression("rate(1 hour)")
)

rule.add_target(targets.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 aws_cdk.aws_iam as iam
import aws_cdk.aws_stepfunctions as sfn


rule = events.Rule(self, "Rule",
    schedule=events.Schedule.rate(cdk.Duration.minutes(1))
)

dlq = sqs.Queue(self, "DeadLetterQueue")

role = iam.Role(self, "Role",
    assumed_by=iam.ServicePrincipal("events.amazonaws.com")
)
state_machine = sfn.StateMachine(self, "SM",
    definition=sfn.Wait(self, "Hello", time=sfn.WaitTime.duration(cdk.Duration.seconds(10))),
    role=role
)

rule.add_target(targets.SfnStateMachine(state_machine,
    input=events.RuleTargetInput.from_object({"SomeParam": "SomeValue"}),
    dead_letter_queue=dlq
))

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.

import aws_cdk.aws_batch as batch
from aws_cdk.aws_ecs import ContainerImage


job_queue = batch.JobQueue(self, "MyQueue",
    compute_environments=[batch.JobQueueComputeEnvironment(
        compute_environment=batch.ComputeEnvironment(self, "ComputeEnvironment",
            managed=False
        ),
        order=1
    )
    ]
)

job_definition = batch.JobDefinition(self, "MyJob",
    container=batch.JobDefinitionContainer(
        image=ContainerImage.from_registry("test-repo")
    )
)

queue = sqs.Queue(self, "Queue")

rule = events.Rule(self, "Rule",
    schedule=events.Schedule.rate(cdk.Duration.hours(1))
)

rule.add_target(targets.BatchJob(job_queue.job_queue_arn, job_queue, job_definition.job_definition_arn, job_definition,
    dead_letter_queue=queue,
    event=events.RuleTargetInput.from_object({"SomeParam": "SomeValue"}),
    retry_attempts=2,
    max_event_age=cdk.Duration.hours(2)
))

Invoke a 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 aws_cdk.aws_apigateway as api
import aws_cdk.aws_lambda as lambda_


rule = events.Rule(self, "Rule",
    schedule=events.Schedule.rate(cdk.Duration.minutes(1))
)

fn = lambda_.Function(self, "MyFunc",
    handler="index.handler",
    runtime=lambda_.Runtime.NODEJS_12_X,
    code=lambda_.Code.from_inline("exports.handler = e => {}")
)

rest_api = api.LambdaRestApi(self, "MyRestAPI", handler=fn)

dlq = sqs.Queue(self, "DeadLetterQueue")

rule.add_target(
    targets.ApiGateway(rest_api,
        path="/*/test",
        method="GET",
        stage="prod",
        path_parameter_values=["path-value"],
        header_parameters={
            "Header1": "header1"
        },
        query_string_parameters={
            "QueryParam1": "query-param-1"
        },
        dead_letter_queue=dlq
    ))

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 = events.Rule(self, "Rule",
    schedule=events.Schedule.expression("rate(1 minute)")
)

rule.add_target(targets.EventBus(
    events.EventBus.from_event_bus_arn(self, "External", "arn:aws:events:eu-west-1:999999999999:event-bus/test-bus")))