Question:
I need some aws EventBridge CDK deployment- Python example ?
Did anyone has some code ?
Answer:
The following example is a well working Python CDK code.
The example demonstrates how to deploy an AWS EventBridge that simultaneously triggers a Step Function and a Lambda Function using AWS CDK (Cloud Deployment Kit).
by yl.
Pre-requisite:
- Python 3.7
- AWS CDK
Steps:
1) Deploys a lambda function
2) Prepares resources: EventBus, EventPattern (an EventBridge filter will be explained later on)
3) Creates a Step functions StateMachine
4) Creates rule using resources: EventBus, EventPattern, Targets: Lambda and State-Machine
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from aws_cdk import aws_events as events from aws_cdk import aws_events_targets as targets from aws_cdk import ( aws_lambda as _lambda, aws_stepfunctions as sfn, aws_stepfunctions_tasks as sfn_tasks ) from aws_cdk import core import typing class CdkEventBridgeStack(core.Stack): def __init__(self, scope: core.Construct, id: str, **kwargs) -> None: super().__init__(scope, id, **kwargs) # 1) deploy lambda function base_lambda = CdkEventBridgeStack.lambdaDeploy(self) # 2) prepare resources EventBus, EventPattern, Rule-Target eventBus, eventPattern, lambdaTarget1 = CdkEventBridgeStack.creEventBusAndEventPatternAndLambdaTarget(self, base_lambda) # 3) create step functions StateMachine stateMachineTarget = CdkEventBridgeStack.createStateMachine(self, base_lambda) # 4) create rule using resources: EventBus, EventPattern, Rule-Targets: Lambda and State-Machine CdkEventBridgeStack.createRule(self, [lambdaTarget1, stateMachineTarget], eventBus, eventPattern) # ----------------------------------------------------------------------------------- @staticmethod def lambdaDeploy(this) -> None: base_lambda = _lambda.Function(this, 'MyLambda', function_name='MyLambda1', handler='testTargtetLambda.lambda_handler', runtime=_lambda.Runtime.PYTHON_3_7, code=_lambda.Code.asset('cdk_event_bridge/functions'), ) return base_lambda # ----------------------------------------------------------------------------------- @staticmethod def creEventBusAndEventPatternAndLambdaTarget(this, base_lambda: _lambda.IFunction): eventBus = events.EventBus(scope=this, id="orders1", event_bus_name="orders2") eventPattern = events.EventPattern(source=['XXX']) lambdaTarget1 = targets.LambdaFunction(handler=base_lambda) return eventBus, eventPattern, lambdaTarget1 # ----------------------------------------------------------------------------------- @staticmethod def createRule(this, targetsList : typing.Optional[typing.List["IRuleTarget"]] = None, eventBus: typing.Optional["IEventBus"]=None, eventPattern: typing.Optional["EventPattern"]=None): events.Rule(scope=this, id="x123", rule_name="routeToLambda", targets=targetsList, description="cdk Test Rule navigates to Lambda", event_bus=eventBus, event_pattern=eventPattern, ) # ----------------------------------------------------------------------------------- @staticmethod def createStateMachine(this, lambda_function: _lambda.IFunction): submit_job_activity = sfn.Activity( this, "SubmitJob" ) check_job_activity = sfn.Activity( this, "CheckJob" ) submit_job = sfn.Task( this, "Submit Job", # task=sfn_tasks.InvokeActivity(submit_job_activity), task=sfn_tasks.InvokeFunction(lambda_function), result_path="$.guid", ) get_status = sfn.Task( this, "Get Job Status", # task=sfn_tasks.InvokeActivity(check_job_activity), task=sfn_tasks.InvokeFunction(lambda_function), input_path="$.guid", result_path="$.status", ) finalStatus = sfn.Succeed( this, 'Final Job Status' ) # definition = submit_job.next(get_status).end_states(sfn.Succeed()) definition = submit_job\ .next(get_status) ##.next(finalStatus) machineHandler = sfn.StateMachine( this, "StateMachine222", definition=definition, state_machine_name="CdkTestStateMachine", timeout=core.Duration.seconds(30), ) # machine: aws_cdk.aws_stepfunctions.IStateMachine stateMachineTarget = targets.SfnStateMachine(machine=machineHandler) return stateMachineTarget # ----------------------------------------------------------------------------------- |
Note:
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code=_lambda.Code.asset('cdk_event_bridge/functions'), |
on the Lambda function deployment
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base_lambda = _lambda.Function(this, 'MyLambda', function_name='MyLambda1', handler='testTargtetLambda.lambda_handler', runtime=_lambda.Runtime.PYTHON_3_7, code=_lambda.Code.asset('cdk_event_bridge/functions'), ) |
The _lambda.Code.asset points to the ‘functions’ folder where the lambda code is located
when the folder hierarchy is:
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/cdk_event_bridge+ +-cdk_event_bridge_stack.py <= this cdk deployment script +-/functions/+ <= a folder +-testTargtetLambda.py <= Lambda code |