Unguis

Sinatra app to serve thumbnails for web resources in Europeana

Configuration

Thumbnails are expected to be stored in an Amazon S3 bucket.

This app uses the AWS SDK to connect to S3. You will need to configure in environment variables:

• AWS_REGION: region of the S3 bucket
• AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY: AWS credentials for read access to objects in the bucket
• AMAZON_S3_BUCKET: name of the bucket

Usage

Start the app using Puma: bundle exec puma -C config/puma.rb

Given your app is running on thumbs.example.com, and a web resource with URI http://provider.example.com/object/123.png, request a thumbnail at: http://thumbs.example.com/?uri=http%3A%2F%2Fprovider.example.com%2Fobject%2F123.png

Response strategies

By default, Unguis will serve thumbnails in the HTTP response it sends to clients itself.

Alternatively, it can be configured to respond with HTTP redirects to S3, by setting the environment variable RESPOND_WITH_REDIRECTS=1.

Caching thumbnails

Response headers include ETag and Last-Modified, facilitating client-side caching of thumbnails.

License

Licensed under the EUPL V.1.1.

For full details, see LICENSE.md.