Example of a custom CDK construct library for S3 - Lambda - S3 integration.

This is a simple demo to show how to create, publish and use your custom CDK construct libraries. In this project we have a construct that contains three resources:

• source S3 bucket
• processing lambda function
• destination S3 bucket

The user of the construct only needs to provide the code and lambda handler name and eveything else will be created by the construct: Here is a python example how this construct will be used by developers:

from aws_cdk import core
from aws_cdk.aws_lambda import AssetCode
from devax import s3_lamdba_s3

class CdkCustomConstructExampleStack(core.Stack):

    def __init__(self, scope: core.Construct, id: str, **kwargs) -> None:
        super().__init__(scope, id, **kwargs)
        lambda_code = AssetCode.from_asset('code')
        s3_lamdba_s3.S3LambdaS3(self, 'customLibraryLambda', code=lambda_code, handler='app.handler')

To demonstrate the ability to leverage CDK abstractions we have the following constraints about the construct:

• s3 buckets are versioned and encrypted by default.
• lambda function runtime is always python in version 3.8, so there is no need to pass it by the user
• the lambda function can only read from the source S3 bucket
• the lambda function can only write/delete from the destination S3 bucket
• writing an object to a source S3 bucket will trigger the lambda function

Getting started

• npm install install the node modules
• npm run build compile typescript to js
• npm run test run tests

JSII setup

• install jsii this will include jsii-pacmak
• add the required configuration to your package.json

{
...
  "author": {
    "name": "YOUR NAME"
  },
  "repository": {
    "url": "https://github.com/YOUR_GITHUB_REPO/s3-lambda-s3",
    "type": "git"
  },
  "license": "Apache-2.0"
...
}

• you need to provide your name, license, and repository information to be able to publish a software package
• add jsii configuration to your package.json, in this example we use only python, but you can also generate packages for java and c#, check the configuration documentation

  "jsii": {
    "outdir": "dist",
    "targets": {
      "python": {
        "distName": "PACKAGENAME.s3-lambda-s3",
        "module": "PACKAGENAME.s3_lambda_s3"
      }
    }
  },

Build and publish your package

• jsii will generate a .jsii file in your root project folder
• jsii-pacmak will read the .jsii config and generate binary files that were specified in the jsii block in package.json
• twine upload DIR will upload a python wheel to a public repository, you can also use you private repo such as Nexus, Artifactory or AWS CodeArtifact