aws(学习笔记第三十二课) 深入使用cdk

• 使用cdk生成aws API Gateway+lambda以及eventbridge等等

学习内容：

• 使用aws API Gateway+lambda
• 使用event bridge练习producer和consumer

---

1. 使用aws API Gateway+lambda

1.1. 以前的练习

• 以前的例子
  API Gateway + lambda这个例子中已经使用了手动创建，使用练习了aws API Gateway+lambda
• 使用cdk来创建
  这里，采用cdk的方式来创建API Gateway + lambda。
  代码链接 api-cors-lambda

1.2. 使用cdk创建API Gateway + lambda

• 整体架构
  
• 代码解析
  • 创建lambda函数

    	   base_lambda = _lambda.Function(self, 'ApiCorsLambda',
    	   handler='lambda-handler.handler',
    	   runtime=_lambda.Runtime.PYTHON_3_12,
    	   code=_lambda.Code.from_asset('lambda'))
    

    注意，这里没有创建VPC，因为这里不需要显示的创建VPC。
    

    • 创建API并且添加resource

              base_api = _apigw.RestApi(self, 'ApiGatewayWithCors',
                                        rest_api_name='ApiGatewayWithCors')
      
              example_entity = base_api.root.add_resource(
                  'example',
              default_cors_preflight_options=_apigw.CorsOptions(
                      allow_methods=['GET', 'OPTIONS'],
                      allow_origins=_apigw.Cors.ALL_ORIGINS)
      

      

    • 创建LambdaIntegration将API和lambda进行绑定

            example_entity_lambda_integration = _apigw.LambdaIntegration(
                  base_lambda,
                  proxy=False,
                  integration_responses=[
                      _apigw.IntegrationResponse(
                          status_code="200",
                          response_parameters={
                              'method.response.header.Access-Control-Allow-Origin': "'*'"
                          }
                      )
                  ]
              )
      

      

    • 对API加入method

            example_entity.add_method(
                  'GET', example_entity_lambda_integration,
                  method_responses=[
                      _apigw.MethodResponse(
                          status_code="200",
                          response_parameters={
                              'method.response.header.Access-Control-Allow-Origin': True
                          }
                      )
                  ]
              )
      

      

1.3. 确认cdk创建API Gateway + lambda

• 执行创建的cdk

  	cdk --require-approval never deploy
  

• 查看创建的结果

  • lambda创建结果
    

  • API创建结果
    

  • 确认API的调用URL
    

  • 访问API的调用URL
    之后不要忘记cdk destroy
    

2. 使用event bridge练习producer和consumer

2.1. 代码链接

api-eventbridge-lambda的代码链接
这里主要练习使用eventbridge，进行producer和consumer的练习。

2.2. 开始练习

• 整体架构
  
• 代码解析

  • 生成producer

    			        #
    			        # Producer Lambda
    			        #
    			        event_producer_lambda = _lambda.Function(self, "eventProducerLambda",
    			                                                 runtime=_lambda.Runtime.PYTHON_3_12,
    			                                                 handler="event_producer_lambda.lambda_handler",
    			                                                 code=_lambda.Code.from_asset("lambda")
    			                                                 )
    			
    			        event_policy = iam.PolicyStatement(effect=iam.Effect.ALLOW, resources=['*'], actions=['events:PutEvents'])
    			
    			        event_producer_lambda.add_to_role_policy(event_policy)
    

    这里，producer被赋予权限putEvents，因为之后要向eventbridge进行putEvents操作。
    

  • producer的处理代码

    	def lambda_handler(event, context):
    	    eventbridge_client = boto3.client('events')
    	    request_body = event["body"]
    	    if request_body is None:
    	        request_body = ""
    	    # Structure of EventBridge Event
    	    eventbridge_event = {
    	        'Time': datetime.datetime.now(),
    	        'Source': 'com.mycompany.myapp',
    	        'Detail': request_body,
    	        'DetailType': 'service_status'
    	    }
    	    logger.info(eventbridge_event)
    	
    	    # Send event to EventBridge
    	    response = eventbridge_client.put_events(
    	        Entries=[
    	            eventbridge_event
    	        ]
    	    )
    	
    	    logger.info(response)
    	
    	    # Returns success reponse to API Gateway
    	    return {
    	        "statusCode": 200,
    	        "body": json.dumps({
    	            "result": "from Producer"
    	        }),
    	    }
    

    这里，使用了boto3这个python package，AWS ‌Boto3‌ 是亚马逊云服务（AWS）官方提供的 Python SDK，主要用于通过代码与 AWS 服务进行交互和管理。这里使用boto3向eventbridge进行putEvents。

  • consumer1和consumer2

    			        #
    			        # Approved Consumer1
    			        #
    			        event_consumer1_lambda = _lambda.Function(self, "eventConsumer1Lambda",
    			                                                  runtime=_lambda.Runtime.PYTHON_3_8,
    			                                                  handler="event_consumer_lambda.lambda_handler",
    			                                                  code=_lambda.Code.from_asset("lambda")
    			                                                  )
    			
    			        event_consumer1_rule = events.Rule(self, 'eventConsumer1LambdaRule',
    			                                           description='Approved Transactions',
    			                                           event_pattern=events.EventPattern(source=['com.mycompany.myapp']
    			                                                                             ))
    			
    			        event_consumer1_rule.add_target(targets.LambdaFunction(handler=event_consumer1_lambda))
    			
    			        #
    			        # Approved Consumer2
    			        #
    			        event_consumer2_lambda = _lambda.Function(self, "eventConsumer2Lambda",
    			                                                  runtime=_lambda.Runtime.PYTHON_3_8,
    			                                                  handler="event_consumer_lambda.lambda_handler",
    			                                                  code=_lambda.Code.from_asset("lambda")
    			                                                  )
    			
    			        event_consumer2_rule = events.Rule(self, 'eventConsumer2LambdaRule',
    			                                           description='Approved Transactions',
    			                                           event_pattern=events.EventPattern(source=['com.mycompany.myapp']
    			                                                                             ))
    			        event_consumer2_rule.add_target(targets.LambdaFunction(handler=event_consumer2_lambda))
    

    consumer1和consumer2类似，就是接受到了eventbridge的event之后，进行log输出。

    			def lambda_handler(event, context):
    			    logger.info(event)
    			
    			    return {
    			        "statusCode": 200,
    			        "body": json.dumps({
    			            "result": "testing..."
    			        }),
    			    }
    

    

  • consumer3使用kinesisfirehose对event进行接受，并保存到S3 bucket上

    	        #
    	        # Approved Consumer3
    	        #
    	
    	        # Create S3 bucket for KinesisFirehose destination
    	        ingest_bucket = s3.Bucket(self, 'test-ngest-bucket')
    	
    	        # Create a Role for KinesisFirehose
    	        firehose_role = iam.Role(
    	            self, 'myRole',
    	            assumed_by=iam.ServicePrincipal('firehose.amazonaws.com'))
    	
    	        # Create and attach policy that gives permissions to write in to the S3 bucket.
    	        iam.Policy(
    	            self, 's3_attr',
    	            policy_name='s3kinesis',
    	            statements=[iam.PolicyStatement(
    	                actions=['s3:*'],
    	                resources=['arn:aws:s3:::' + ingest_bucket.bucket_name + '/*'])],
    	                # resources=['*'])],
    	            roles=[firehose_role],
    	        )
    	
    	        event_consumer3_kinesisfirehose = _firehose.CfnDeliveryStream(self, "consumer3-firehose",
    	                                                                      s3_destination_configuration=_firehose.CfnDeliveryStream.S3DestinationConfigurationProperty(
    	                                                                          bucket_arn=ingest_bucket.bucket_arn,
    	                                                                          buffering_hints=_firehose.CfnDeliveryStream.BufferingHintsProperty(
    	                                                                              interval_in_seconds=60
    	                                                                          ),
    	                                                                          compression_format="UNCOMPRESSED",
    	                                                                          role_arn=firehose_role.role_arn
    	                                                                      ))
    	
    	        event_consumer3_rule = events.Rule(self, 'eventConsumer3KinesisRule',
    	                                           description='Approved Transactions',
    	                                           event_pattern=events.EventPattern(source=['com.mycompany.myapp']
    	                                                                             ))
    	        event_consumer3_rule.add_target(targets.KinesisFirehoseStream(stream=event_consumer3_kinesisfirehose))
    

    

  • 将producer通过API Gateway进行公开

    	        # defines an API Gateway REST API resource backed by our "atm_producer_lambda" function.
    	        api = api_gw.LambdaRestApi(self, 'SampleAPI-EventBridge-Multi-Consumer',
    	                             handler=event_producer_lambda,
    	                             proxy=False
    	                             )
    	        items = api.root.add_resource("items")
    	        items.add_method("POST")  # POST /items
    

2.3. 代码部署的确认

接下来进行cdk deploy来确认执行效果。

• 一个producer与两个consumer，都是lambda
  
• 第三个consumer，一个kinesisFireHose
  
• API的producer
  

2.4. 对部署进行测试

• 对API进行测试调用
  返回了正常的结果。这里，需要对请求正文request body一定要设定参数这里设置如下。

  {"item1":"123","item2":"234"}
  

  使用API调用，之后启动producer的lamdba，向eventbridge进行putEvents。
  
• 对consumer1和consumer2进行确认
  
• 对consumer3进行确认
  这里主要是对S3 bucket进行确认。可以看到，
  producer -> event -> eventbridge -> consumer3 -> kinesis firehose -> S3 bucket
  最后cdk destroy。