Simple S3 Proxy

This is a very simple S3 proxy interface that is implemented by AWS API Gateway and Lambda.

Development

It is developed with NodeJS 10 + TypeScript + Serverless framework. You can easily add some API editing handler.ts file with some editors such as Visual Studio Code.

1. yarn to install dependencies.
2. code . to edit handler.ts file.
3. export BUCKET_NAME=something_awesome_you_want to set a S3 bucket name to environment variable.
4. yarn deploy to deploy this into AWS environment.

S3 Bucket

Before deploying this stack, please set BUCKET_NAME environment variable first. This is a S3 bucket to persist JSON objects and that is created by this CloudFormation stack. If you feel boring to set this value everytime before deploying, it is a good option to write this value into .envrc file and use direnv to export it automatically.

AWS credentials

Of course, you should have an AWS account and set its credentials via environment variables. This article may help you.

This credentials should be permitted with API Gateway, Lambda, S3, CloudWatch and CloudFormation to deploy a stack. Please check your permission when you encounter some errors while deploying.

APIs

API	Description	Response
GET	Get a stored object. curl -XGET https://API/object-key	content or null
PUT	Put an object to store. curl -XPUT https://API/object-key -d '{JSON}'	true or false
DELETE	Delete a stored object. curl -XDELETE https://API/object-key	true

There is no auth for this API to simply use, but you can add that feature easily via Lambda Authorizer.

Actual example

After your first deploy, Serverless framework returns a report like this.

Service Information
service: simple-s3-proxy
stage: production
region: ap-northeast-2
stack: simple-s3-proxy-production
resources: 21
api keys:
  None
endpoints:
  PUT - https://API-ID.execute-api.ap-northeast-2.amazonaws.com/production/{key}
  GET - https://API-ID.execute-api.ap-northeast-2.amazonaws.com/production/{key}
  DELETE - https://API-ID.execute-api.ap-northeast-2.amazonaws.com/production/{key}
functions:
  put: simple-s3-proxy-production-put
  get: simple-s3-proxy-production-get
  delete: simple-s3-proxy-production-delete
layers:
  None

An endpoint like https://API-ID.execute-api.ap-northeast-2.amazonaws.com/production/{key} is the endpoint to call. For example, you can put your {"hello":"world"} JSON with the foo key with below curl command.

curl -XPUT https://API-ID.execute-api.ap-northeast-2.amazonaws.com/production/foo -d '{"hello":"world"}'