rights reserved. S U M M I T Serverless functions deep dive Danilo Poccia Principal Evangelist, Serverless AWS @danilop Olaf Conijn IT Architect Moneyou [email protected]
rights reserved. S U M M I T AWS operational responsibility models On-Premises Cloud Less More Compute Virtual Machine EC2 Elastic Beanstalk AWS Lambda Fargate Databases MySQL MySQL on EC2 RDS MySQL RDS Aurora Aurora Serverless DynamoDB Storage Storage S3 Messaging ESBs Amazon MQ Kinesis SQS / SNS Analytics Hadoop Hadoop on EC2 EMR Elasticsearch Service Athena
rights reserved. S U M M I T Serverless applications Services (anything) Changes in data state Requests to endpoints Changes in resource state Event source Function Node.js Python Java C# / F# / PowerShell Go Ruby Runtime API
rights reserved. S U M M I T Anatomy of a Lambda function Handler() function Function to be executed upon invocation Event object Data sent during Lambda function Invocation Context object Methods available to interact with runtime information (request ID, log group, more) import json def lambda_handler(event, context): # TODO implement return { 'statusCode': 200, 'body': json.dumps('Hello World!') }
rights reserved. S U M M I T Lambda Layers Lets functions easily share code: Upload layer once, reference within any function Promote separation of responsibilities, lets developers iterate faster on writing business logic Built in support for secure sharing by ecosystem
rights reserved. S U M M I T Using Lambda Layers • Put common components in a ZIP file and upload it as a Lambda Layer • Layers are immutable and can be versioned to manage updates • When a version is deleted or permissions to use it are revoked, functions that used it previously will continue to work, but you won’t be able to create new ones • You can reference up to five layers, one of which can optionally be a custom runtime Lambda Layers arn:aws:lambda:region:accountId:layer:shared-lib Lambda Layers arn:aws:lambda:region:accountId:layer:shared-lib:2 Lambda Layers arn:aws:lambda:region:accountId:layer:shared-lib:3
rights reserved. S U M M I T Lambda Runtime API Bring any Linux compatible language runtime Powered by new Runtime API - Codifies the runtime calling conventions and integration points At launch, custom runtimes powering Ruby support in AWS Lambda, more runtimes from partners (like Erlang) Custom runtimes distributed as “layers” Rule Stack
rights reserved. S U M M I T Runtime Bootstrap • The bootstrap executable act as a bridge between the Runtime HTTP API and the Function to be executed • Bootstrap needs to manage response/error handling, context creation and function execution • Information on the interface endpoint and the function handler are shared as environment variables /runtime API /invocation/next /init/error /ID/error /invocation/ID/response /invocation/ID/error bootstrap Process events/headers Clean up Initialize and Invoke function Response/Error handling Lambda Function
rights reserved. S U M M I T AWS Serverless Application Model (SAM) AWS CloudFormation extension optimized for serverless Special serverless resource types: Functions, APIs, SimpleTables, Layers, and Applications Supports anything AWS CloudFormation supports Open specification (Apache 2.0) https://aws.amazon.com/serverless/sam
rights reserved. S U M M I T SAM template AWSTemplateFormatVersion: '2010-09-09’ Transform: AWS::Serverless-2016-10-31 Resources: GetFunction: Type: AWS::Serverless::Function Properties: Handler: index.get Runtime: nodejs8.10 CodeUri: src/ Policies: - DynamoDBReadPolicy: TableName: !Ref MyTable Events: GetResource: Type: Api Properties: Path: /resource/{resourceId} Method: get MyTable: Type: AWS::Serverless::SimpleTable Just 20 lines to create: • Lambda function • IAM role • API Gateway • DynamoDB table O pen Source
rights reserved. S U M M I T AWS SAM Command Line Interface (AWS SAM CLI) CLI tool for local development, debugging, testing, deploying, and monitoring of serverless applications Supports API Gateway “proxy-style” and Lambda service API testing Response object and function logs available on your local machine Uses open source docker-lambda images to mimic Lambda’s execution environment such as timeout, memory limits, runtimes Can tail production logs from CloudWatch logs Can help you build in native dependencies https://aws.amazon.com/serverless/sam
rights reserved. S U M M I T Use SAM CLI to package and deploy SAM templates pip install --user aws-sam-cli sam init --name my-app --runtime python cd my-app/ sam local ... # generate-event/invoke/start-api/start-lambda sam validate # The SAM template sam build # Depending on the runtime sam package --s3-bucket my-packages-bucket \ --output-template-file packaged.yaml sam deploy --template-file packaged.yaml \ --stack-name my-stack-prod sam logs -n MyFunction --stack-name my-stack-prod -t # Tail sam publish # To the Serverless Application Repository O pen Source CodePipeline Use CloudFormation deployment actions with any SAM application Jenkins Use SAM CLI plugin
rights reserved. S U M M I T With the AWS Serverless Application Repository: Developers can… • Discover and deploy ready-made apps and code samples • Combine applications in the app repository with their own via Nested Applications • Customize open-source apps to get started quickly • Share apps privately or publish apps for public use
rights reserved. S U M M I T TweetSource: Type: AWS::Serverless::Application Properties: Location: ApplicationId: arn:aws:serverlessrepo:... SemanticVersion: 2.0.0 Parameters: TweetProcessorFunctionName: !Ref MyFunction SearchText: '#serverless -filter:nativeretweets' Nested apps to simplify solving recurring problems Standard Component Custom Business Logic Polling schedule (CloudWatch Events rule) trigger TwitterProcessor SearchCheckpoint TwitterSearchPoller Twitter Search API
rights reserved. S U M M I T AWS SAM Template Capabilities • Can mix in other non-SAM CloudFormation resources in the same template • i.e. Amazon S3, Amazon Kinesis, AWS Step Functions • Supports use of Parameters, Mappings, Outputs, etc • Supports Intrinsic Functions • Can use ImportValue (exceptions for RestApiId, Policies, StageName attributes) • YAML or JSON
rights reserved. S U M M I T AWS Lambda Environment Variables • Key-value pairs that you can dynamically pass to your function • Available via standard environment variable APIs such as process.env for Node.js or os.environ for Python • Can optionally be encrypted via AWS Key Management Service (KMS) • Allows you to specify in IAM what roles have access to the keys to decrypt the information • Useful for creating environments per stage (i.e. dev, testing, production)
rights reserved. S U M M I T Amazon API Gateway Stage Variables Stage variables act like environment variables • Use stage variables to store configuration values • Stage variables are available in the $context object • Values are accessible from most fields in API Gateway • Lambda function ARN • HTTP endpoint • Custom authorizer function name • Parameter mappings
rights reserved. S U M M I T MyLambdaFunction: Type: AWS::Serverless::Function Properties: Handler: index.handler Runtime: nodejs6.10 AutoPublishAlias: !Ref ENVIRONMENT DeploymentPreference: Type: Linear10PercentEvery10Minutes Alarms: # A list of alarms that you want to monitor - !Ref AliasErrorMetricGreaterThanZeroAlarm - !Ref LatestVersionErrorMetricGreaterThanZeroAlarm Hooks: # Validation Lambda functions that are run before & after traffic shifting PreTraffic: !Ref PreTrafficLambdaFunction PostTraffic: !Ref PostTrafficLambdaFunction AWS SAM + Safe Deployments
rights reserved. S U M M I T Lambda permissions model Fine grained security controls for both execution and invocation: Execution policies: • Define what AWS resources/API calls can this function access via IAM • Used in streaming invocations • E.g. “Lambda function A can read from DynamoDB table users” Function policies: • Used for sync and async invocations • E.g. “Actions on bucket X can invoke Lambda function Z” • Resource policies allow for cross account configst access
rights reserved. S U M M I T AWS SAM Policy Templates MyQueueFunction: Type: AWS::Serverless::Function Properties: ... Policies: # Gives permissions to poll an SQS Queue - SQSPollerPolicy: queueName: !Ref MyQueue ... MyQueue: Type: AWS::SQS::Queue ...
rights reserved. S U M M I T AWS SAM Best Practices • Use Parameters and Mappings when possible to build dynamic templates based on user inputs and pseudo parameters such as AWS::Region • Use the Globals section to simplify templates • Use Export & ImportValue to share resource information across stacks • Build out multiple environments, such as for Development, Test, Production and even DR using the same template, even across accounts SAM Template Source Control Dev Test Prod
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Label for ABN AMRO products • IT was outsourced to partners • Hosting & development • Core banking & channels Moneyou in 2016 • Started to build a new payment proposition • Need for short time to market & cost efficiency • Need to insource software development in a modern way • Ambition to do DevOps
service compliant configurations are defined. • AWS config keeps track of all resources • Notifies for in compliant configuration • Notifications send to account owner and platform team (incl. ciso) • All production systems run our most critical CIA rating • Stay away from: EC2 or VPC
VPC • Lambdas in VPC suffer additional cold-start time • Additional complexity managing VPC’s • Connectivity to on-prem done through VPC and Direct-Connect/VPN • Solution: API Gateway and IAM to proxy on-prem services • VPCs centrally managed • Lambda’s/features run outside a VPC • Highly scalable, highly available
IP addresses of on-premise servers • API GW Proxy requires Back-end TLS cert to be signed by trusted CA • AWS v4 request signing requires access to underlying HTTP client
scalability • Retry mechanisms for reliability • What if…. strong consistency does matter? Strong consistency • Solution: Use DynamoDB as a lock server • Conditional (atomic) Updates • Consistent reads