Docker container hosting a Cantaloupe instance for the Illinois Digital Library Service.

Instance Overview

• Cantaloupe listens on HTTP port 8182.
• AWS credentials are obtained from a task IAM role. When running locally, these are obtained from an ECS Local Endpoint.
• There are three supported identifier schemes:
  1. Medusa file UUIDs. The S3Source delegate method calls the Medusa HTTP API to look up their object keys.
  2. Full S3 URLs (s3://...).
  3. Strings starting with v/ are video thumbnails for which HttpSource is used to get an image from Kaltura, because of FfmpegProcessor limitations (see below). There are a very small number of these.
• The source for all Medusa content is S3Source and its lookup strategy is ScriptLookupStrategy.
• The derivative cache is S3Cache.
• Format assignments:
  • JPEG: TurboJpegProcessor
  • JPEG2000: KakaduNativeProcessor
  • PDF: PdfBoxProcessor
  • Videos: FfmpegProcessor (which works very poorly with non-filesystem storage, so serving video stills is not advised)
  • Everything else: Java2dProcessor

Build

1. Look at the comment header of image_files/cantaloupe.properties to see what version it's for.
2. Download that version's release zip file into image_files.
   • Of course, you can use any version, as long as the config file contains the right keys for it, and any dependencies are in place.
   • This could be automated, but doing it this way makes it easier to use arbitrary snapshots.
3. Copy env.list.sample to env.list and fill it in. Don't commit it to version control!
4. ./docker-build.sh

Run

Locally

1. aws login (GitHub)
2. docker-compose up --build

It's now listening at http://localhost:8182.

In ECS

In ECS, env.list isn't used, so all of its variables have to be set in the task definition.

1. ./ecr-push.sh
2. ./ecs-deploy.sh
3. Check the status via the AWS web console or ./ecs-status.rb.

ECS Configuration Notes

Images are tagged with the Cantaloupe version. There is also a latest tag applied to the latest version which is what is specified in the task definition. If there is ever a need to revert to a previous version, the task definition must be updated (in Terraform) to specify that version.