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
   

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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
   

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3. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   Clean Code
   

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4. Software Craftsmanship & Clean Code
   

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5. Software Craftsmanship & Clean Code
   

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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
   

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7. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   Single Responsibility Principle
   

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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
   

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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
   

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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
    

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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
    

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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
    

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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" ]
    }
    }
    

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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…
    

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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
    

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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
    

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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
    

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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
    

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19. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    You Ain’t Gonna Need It
    

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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
    

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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
    

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22. Common architecture
    API Database
    Backend
    

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23. Common serverless architecture
    Amazon
    API Gateway
    Amazon
    DynamoDB
    AWS
    Lambda
    

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24. Common serverless architecture
    Amazon
    API Gateway
    Amazon
    DynamoDB
    AWS
    Lambda
    // Validate input
    // CRUD
    // (return)
    

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25. Functionless architecture
    Amazon
    API Gateway
    Amazon
    DynamoDB
    // Validate input
    // CRUD
    // (return)
    

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26. Amazon API Gateway Service Proxy
    Amazon
    API Gateway
    Amazon
    DynamoDB
    https://docs.aws.amazon.com/apigateway/latest/developerguide/getting-started-aws-proxy.html
    

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27. Amazon API Gateway Service Proxy
    Amazon
    API Gateway
    Amazon
    DynamoDB
    https://velocity.apache.org/engine/devel/vtl-reference.html
    

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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
    

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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
    

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30. Functionless architecture
    Amazon
    API Gateway
    Amazon
    DynamoDB
    // Validate input
    // CRUD
    // (return)
    

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31. Functionless architecture
    AWS
    AppSync
    Amazon
    DynamoDB
    Amazon Aurora
    Serverless
    Amazon
    Elasticsearch Service
    

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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
    

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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
    

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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
    

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35. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Keep it Simple Stupid
    aka Conclusion
    

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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
    

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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
    

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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
    

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39. Keep it… or leave it
    is not always needed
    You can save costs and optimize performance
    when functions are just passthrough or mapping
    

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40. Thank you!
    © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Jérôme Van Der Linden
    AWS Solutions Architect
    

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41. © 2020, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    

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