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CDK

Links: 102 AWS DVA Index

CDK

  • Stands for Cloud Development Kit.
  • Define your cloud infrastructure using a familiar language:
    • JavaScript/TypeScript, Python, Java, and .NET
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  • Contains high level components called constructs
  • The code is compiled into a CloudFormation template (JSON/YAML)
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    • It is a step above CloudFormation and way easier to work with
    • Since the code is compiled we can find out errors if any before generating the template
  • You can therefore deploy infrastructure and application runtime code together
    • Great for Lambda functions
    • Great for Docker containers in ECS / EKS
In CDK there is something known as constructs

Different layers of constructs

L1

  • Can be called CFN Resources which represents all resources directly available in CloudFormation.
  • Construct names start with Cfn (e.g., CfnBucket)
  • You must explicitly configure all resource properties.
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L2

  • Represents AWS resources but with a higher level (intent-based API)
  • Similar functionality as L1 but with convenient defaults and boilerplate
    • You don't need to know all the details about the resource properties
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L3

  • Can be called Patterns, which represents multiple related resources.
  • Helps you complete common tasks in AWS.
  • Examples:
    • aws-apigateway.LambdaRestApi represents an API Gateway backed by a Lambda function
    • aws-ecs-patterns.ApplicationLoadBalancerFargateService which represents an architecture that includes a Fargate cluster with Application Load Balancer
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Development using CDK

  • Create an app
  • Add code
  • Build the app (optional)
  • Synthesise one or more stacks in the app to create an AWS CloudFormation template.
    • The synthesis step catches logical errors in defining your AWS resources.
  • Deploy: cdk deploy

CDK vs SAM

  • SAM:
    • Serverless focused
    • Write your template declaratively In JSON or YAML
    • Great for quickly getting started with Lambda
    • Leverages CloudFormation
  • CDK:
    • All AWS services
    • Write infra in a programming language JavaScript/TypeScript, Python, Java, and .NET
    • Leverages CloudFormation

Last updated: 2023-03-01