This code is a good example of serverless anti-pattern. It works, I managed to solve problems with CORS, but the whole approach is wrong. Use of koa.js server adds unnecessary latency to AWS Lambda cold start. A proper way is to create separate handlers for each endpoint, and configure them in AWS API Gateway. See the improved version here

This is a demo project to show how to create and deploy a serverless application on AWS cloud. It provides a simple web interface for user management.

Back end:

• node.js
• koa.js v2
• serverless-http
• DynamoDB

Front end:

• mithril.js

To start playing with it, clone the repository and install node packages:

git clone https://github.com/ilog2000/serverless-user-mgmt
cd serverless-user-mgmt
yarn

To run it locally, you will need to set up a local copy of DynamoDB. Note, that it requres Java runtime to be available on your machine. After download, unzip an archive, and execute the following command:

java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedDb

Now create .env file from .env.example.

Further steps are to execute scripts from package.json to create and fill in DynamoDB 'users' table:

yarn dev-dynamodb-create
yarn dev-dynamodb-populate

... and to check the results:

yarn dev-dynamodb-query

In order to run the API back end, you can use the next script:

yarn dev-lambda

The serverless-offline plugin is executed behind the scene.

The following command will start a development server for the front end (just ensure that client/config.js BASE_API_URL points to http:https://localhost:3000; if not - modify and run yarn build to re-build front end distribution):

yarn serve

The web application can be open on localhost:5000.

NOTE: Do not forget to update your .env file with production settings.

You can deploy to AWS with these commands:

yarn prod-lambda
yarn prod-dynamodb-create
yarn prod-dynamodb-populate
yarn prod-dynamodb-delete
yarn prod-dynamodb-query
yarn s3-create-bucket
yarn s3-upload-objects
yarn s3-configure-site

These scripts create AWS Lambda function for API, DynamoDB storage, and static web site located in S3 bucket.

You will need a very convenient REST Client plugin for Visual Studio Code to use test.http file, which contains descriptors of HTTP requests to API.