This is a demo setup to explore flexible caching of build artifacts (e.g. npm node_module folders or maven repositories) in a concourse pipeline. A detailed description of the approach used in this repo and how it works is available on our blog.

In short: We use a Task instead of a Resource to

• find last parent commit id that changed package file (e.g. packages.json, pom.xml)
• check cache for package tarball (http file server, but can swap in a different one)
• if package tarball has not been built yet, invoke package manager to fetch packages and generate tarball
• download and extract package tarball

The scripts should run in any standard docker image with a proper bash and curl, so you can easily incorporate them in your existing CI pipelines.

fly -t ci set-pipeline -c ci/pipeline.yml --load-vars-from ci/credentials.yml -p concourse-cached-pipeline

fly -t ci execute --config ci/cache-a.yml --input repo=. --exclude-ignore