AWS S3 Lambda Function

AWS Lambda function that listens for S3 put events for a specified S3 bucket, retrieves the uploaded image file, creates the thumbnail, and puts them back to the specified S3 bucket's 'thumbnails' folder with the same key structure.

Install dependencies with pip

pip install Pillow

Install the Pillow module in the thumbnail-s3-lambda directory.

Create Lambda Function

Create the S3 Lambda function with the following configuration settings:

Runtime: Python 2.7
Handler: thumbnail-genrator.lambda_handler
Triggers: S3: bucket-media
Prefix: media/

The prefix is used to avoid cyclic loop for put events in the same parent bucket.

Zip the contents of the thumbnail-s3-lambda. Upload the zip file to the lambda function.

Improvements

1. Add logging. Eg. post the log messages to loggly