After v0.9.0, the API and configurations of serverless-s3-local changed. So if you want to use old API and configurations, please continue to use v0.8.X. But v0.8.X are not maintained.

serverless-s3-local is a Serverless plugin to run S3 clone in local. This is aimed to accelerate development of AWS Lambda functions by local testing. I think it is good to collaborate with serverless-offline.

Use npm

npm install serverless-s3-local --save-dev

Use serverless plugin install

sls plugin install --name serverless-s3-local

serverless-s3-local uses minio as its backend. So you have to install minio your environment.

Install manually Please see these documents and install minio into your environment.

Fetch from web at first launch of serverless-s3-local Use fetchFromWeb property. If this property is set true, serverless-s3-local fetches minio binary from web.

serverless.yaml

service: serverless-s3-local-example
provider:
  name: aws
  runtime: nodejs18.x
plugins:
  - serverless-s3-local
  - serverless-offline
custom:
  s3Local:
    minio:
      port: 9000
      fetchFromWeb: false
resources:
  Resources:
    NewResource:
      Type: AWS::S3::Bucket
      Properties:
        BucketName: local-bucket
functions:
  webhook:
    handler: handler.webhook
    events:
      - http:
        method: GET
        path: /
  s3hook:
    handler: handler.s3hook
    events:
      - s3: 
          bucket: local-bucket
          event: s3:ObjectCreated:Put
          existing: true

handler.js

import { S3Client, PutObjectCommand } from "@aws-sdk/client-s3";
export const webhook = async (event, context) => {
  const client = new S3Client({
    forcePathStyle: true,
    credentials: {
      accessKeyId: "minioadmin",
      secretAccessKey: "minioadmin",
    },
    endpoint: "https://localhost:9000",
  });
  await client.send(
    new PutObjectCommand({
      Bucket: "local-bucket",
      Key: "1234",
      Body: Buffer.from("abcd"),
    }),
  );
  return {
    statusCode: 200,
    body: JSON.stringify("ok"),
  };
};
export const s3hook = async (event, context) => {
  console.log(JSON.stringify(event));
  console.log(JSON.stringify(context));
  console.log(JSON.stringify(process.env));
  return {
    statusCode: 200,
    body: JSON.stringify("ok"),
  };
};

Configuration options can be defined in multiple ways. They will be parsed with the following priority:

• custom.s3Local.minio in serverless.yml
• Default values (see table below)

• Start local S3 server with specified root directory and port.
• Create buckets at launching.
• Support S3 events.

This plugin will create a temporary directory to store mock S3 info. You must use the AWS cli to trigger events locally. First, using aws configure set up a new profile, i.e. aws configure --profile s3local. The default creds are

aws_access_key_id = minioadmin
aws_secret_access_key = minioadmin

You can now use this profile to trigger events. e.g. to trigger a put-object on a file at ~/tmp/userdata.csv in a local bucket run: aws --endpoint https://localhost:4569 s3 cp ~/tmp/data.csv s3://local-bucket/userdata.csv --profile s3local

You should see the event trigger in the serverless offline console: info: PUT /local-bucket/user-data.csv 200 16ms 0b and a new object with metadata will appear in your local bucket.

minio doesn't support IndexDocument and ErrorDocument when buckets are exposed as webserver. serverless-s3-local provide a proxy webserver to provide these features.

It is completely personal reason. I cannot continue to maintain motivation of maintain its codebases. So I decided to simplify features and rewrite typescript. If you want to continue to use v0.8.X, please use v0.8.4 or fork it.

• minio
• serverless-offline

This software is released under the MIT License, see LICENSE.