Do more with less code in Serverless

re:Invent 2020 session explaining how to leverage serverless services to reduce the amount of code and number of lambda functions

Transcript

1. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. Do more with less code in Serverless Jérôme Van Der Linden Solutions Architect AWS S V S 3 5 2 - G
2. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. Clean Code Single Responsibility Principle You Ain’t Gonna Need It Keep It Simple Stupid Agenda
3. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. Clean Code
4. Software Craftsmanship & Clean Code
5. Software Craftsmanship & Clean Code
6. SOLID - Single Responsibility Principle YAGNI - You Ain’t Gonna Need It KISS - Keep it Simple Stupid Some clean code principles https://www.amazon.es/Wenger-19201-Navaja-suiza/dp/B000R0JDSI
7. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. Single Responsibility Principle
8. Single Responsibility Principle Do’s Don’ts * - Input validation - Business logic - Transform data - Return result - Event/Input Filtering - Transport data - Orchestration & long transactions * Most of the time
9. Single Responsibility Principle Do’s Don’ts * - Input validation - Business logic - Transform data - Return result - Event/Input Filtering - Transport data - Orchestration & long transactions * Most of the time
10. Serverless is not only AWS Lambda COMPUTE DATA STORES INTEGRATION Amazon DynamoDB Amazon Aurora Serverless Amazon S3 AWS Lambda AWS Fargate Amazon EventBridge Amazon API Gateway Amazon SQS Amazon SNS AWS AppSync AWS Step Functions
11. Event Filtering – the wrong way SNS Topic Publisher if event_type == 'order_created’: lambda_client.invoke('OrderCreation', ...) elif event_type == 'order_placed’: lambda_client.invoke('OrderPlacement', ...) elif event_type == 'order_cancelled’: lambda_client.invoke('OrderCancelation', ...) OrderCreation OrderPlacement OrderCancellation { "event_type": "order_placed", "order": { "id": "232134", "amount": "2341,45", "stock_ref": "AMZN” } } function code Input event OrderFiltering
12. Event Filtering with Amazon SNS SNS Topic Publisher OrderCreation OrderPlacement OrderCancellation OrderCreationEvent: Type: AWS::SNS::Subscription Properties: TopicArn: 'arn:aws:sns:eu-central-1:123456789:OrdersTopic' Protocol: lambda Endpoint: 'arn:aws:lambda:eu-central-1:123456789:function:OrderCreation' FilterPolicy: event_type: - order_created { "event_type": [ "order_created" ] } Filter policy Cloudformation template https://docs.aws.amazon.com/sns/latest/dg/sns-subscription-filter-policies.html
13. Event Filtering with Amazon EventBridge https://docs.aws.amazon.com/eventbridge/latest/userguide/content-filtering-with-event-patterns.html { "Source": "custom.myOrderapp", "EventBusName": "default", "DetailType": "order", "Time": "Wed Jan 29 2020 08:03:18 GMT-0500", "Detail":{ "event_type": "order_created", "order": { "id": "232134", "amount": "2341.45", "stock_ref": "AMZN", "quantity": "3", "result": "approved" } } } EventBridge Event Bus Rules Targets { "source": [ "custom.myOrderapp" ], "detail-type": [ "order" ], "detail": { "event_type": [ "order_created" ], "amount": [ { "numeric": [ ">", 2000 ] } ], "result": [ "approved" ] } }
14. Orchestration – the wrong way invoke invoke if (… ) invoke // else if (success) Notify with SNS n * invoke if (failure) Enqueue error notify with SNS need approval App…
15. Simple orchestration with Lambda destinations invoke invoke if (… ) invoke // else if (success) Notify with SNS n * invoke if (failure) Enqueue error notify with SNS need approval App… Lambda Destinations https://docs.aws.amazon.com/lambda/latest/dg/invocation-async.html#invocation-async-destinations
16. Simple orchestration with Lambda destinations Amazon SNS Amazon EventBridge Amazon Cloudwatch Logs Amazon S3 Amazon SES AWS Config Amazon CloudFormation AWS CodeCommit A S Y N C "DestinationConfig": { "onSuccess": { "Destination": "arn:aws:sns:..." }, "onFailure": { "Destination": "arn:aws:sqs:..." } } Cloudformation template Amazon SNS Amazon EventBridge Amazon SQS AWS Lambda if success: return {...} else: raise Exception(‘Failure', {...}) function code Lambda function A S Y N C
17. Advanced orchestration with AWS Step Functions invoke invoke if (… ) invoke // else if (success) Notify with SNS n * invoke if (failure) Enqueue error notify with SNS need approval App… https://docs.aws.amazon.com/step-functions/latest/dg/welcome.html
18. { "StartAt": "SimpleInvocation", "States": { "SimpleInvocation": { "Type": "Task", "Resource": "arn:aws:lambda:eu-central-1:123456789 "Next": "Choose1or2" }, "Choose1or2": { "Type": "Choice", "Choices": [ { "Variable": "$.foo", "NumericEquals": 1, "Next": "Lambda1" }, { "Variable": "$.foo", "NumericEquals": 2, "Next": "ParallelInvocation" } ], "Default": "Unmatched" }, "Lambda1": { "Type": "Task", "Resource": "arn:aws:lambda:eu-central-1:123456789 Advanced orchestration with AWS Step Functions
19. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. You Ain’t Gonna Need It
20. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. "No server is easier to manage than 'no server' " Werner Vogels VP & CTO Amazon.com
21. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. "No function is easier to manage than 'no function' " Me Solutions Architect AWS
22. Common architecture API Database Backend
23. Common serverless architecture Amazon API Gateway Amazon DynamoDB AWS Lambda
24. Common serverless architecture Amazon API Gateway Amazon DynamoDB AWS Lambda // Validate input // CRUD // (return)
25. Functionless architecture Amazon API Gateway Amazon DynamoDB // Validate input // CRUD // (return)
26. Amazon API Gateway Service Proxy Amazon API Gateway Amazon DynamoDB https://docs.aws.amazon.com/apigateway/latest/developerguide/getting-started-aws-proxy.html
27. Amazon API Gateway Service Proxy Amazon API Gateway Amazon DynamoDB https://velocity.apache.org/engine/devel/vtl-reference.html
28. Amazon API Gateway Request Validation https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-method-request-validation.html Amazon API Gateway Amazon DynamoDB
29. Amazon API Gateway Request Validation https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-method-request-validation.html Amazon API Gateway Amazon DynamoDB
30. Functionless architecture Amazon API Gateway Amazon DynamoDB // Validate input // CRUD // (return)
31. Functionless architecture AWS AppSync Amazon DynamoDB Amazon Aurora Serverless Amazon Elasticsearch Service
32. AWS Step Functions integrations AWS Lambda AWS Batch Amazon DynamoDB Amazon ECS / Fargate Amazon EMR AWS Glue Amazon SageMaker Amazon SNS Amazon SQS AWS Step Functions AWS CodeBuild https://docs.aws.amazon.com/step-functions/latest/dg/concepts-service-integrations.html
33. AWS Step Functions integrations "QueueError": { "Type": "Task", "Resource": "arn:aws:states:::sqs:sendMessage", "Parameters": { "QueueUrl": "https://sqs.eu-central-1.amazonaws.com/123456789012/myQueue", "MessageBody.$": "$.input.message" }, "End": true }, "SendNotification": { "Type": "Task", "Resource": "arn:aws:states:::sns:publish", "Parameters": { "TopicARN": "arn:aws:sns:eu-central- 1:123456789012:myTopic", "Subject": "Lambda1 has successfully finish its job", "Message.$" : "$.input.message" }, "End": true }, SQS SNS
34. Amazon EventBridge integrations https://docs.aws.amazon.com/eventbridge/latest/userguide/eventbridge-targets.html EventBridge Event Bus Rules Targets AWS Batch Amazon EC2 Instance Amazon ECS Task AWS Step Functions Amazon SNS Amazon SQS Amazon Kinesis Data Streams Amazon Kinesis Data Firehose Amazon EventBridge AWS CodeBuild AWS CodePipeline Amazon API Gateway SSM Run Command SSM Automation Amazon Redshift
35. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. Keep it Simple Stupid aka Conclusion
36. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. “There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult.” Tony Hoare Former Professor at Oxford
37. Keep it Simple Simpler functions = Easier to test and maintain Faster to start: less cold start More scalable: higher throughput More secure: less permission needed
38. Keep your code focused on the business Keep it Stupid Business code is the clever part of the function Orchestration is not the responsibility of a Clever
39. Keep it… or leave it is not always needed You can save costs and optimize performance when functions are just passthrough or mapping
40. Thank you! © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved. Jérôme Van Der Linden AWS Solutions Architect
41. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved.