Gatherer is a project that caches build dependencies on ephemeral file systems, such as drone.io. It is built with 3 principles in mind.

1. Minimize dependency hosting expense.
2. Easy to deploy.
3. Easy to maintain.

curl gatherer https://drone.io/github.com/justinabrahms/gatherer/files/gatherer > gatherer
# or on OSX..
curl gatherer https://drone.io/github.com/justinabrahms/gatherer/files/gatherer_osx > gatherer

chmod +x gatherer

Gatherer works by calculating a hash from a list of files indicated by --toHash. It looks for a bundle matching that hash on Amazon's S3. If it finds it, it will download and extract the files. If the hash didn't exist or there was an error during the download, Gatherer will run your --buildCommand which should generate files in --packageDirectories (a comma-separated list of directories). It will archive these files and store them in S3 for later retrieval.

NOTE: The gatherer binary expects you to have 2 environment variables with your S3 credentials: AWS_ACCESS_KEY_ID and AWS_SECRET_ACESS_KEY.

gatherer --packageDirectories="node_modules" \
         --toHash="package.json" \
         --buildCommand="npm install ." \
         --bucketName="dependency-artifacts"