This repository tracks the Docker Official Image source for Ruby:

https://github.com/docker-library/ruby

Local images keep the upstream generated Dockerfile layout, but install the distribution jemalloc package and patch /usr/local/bin/ruby to load libjemalloc.so.2. They set MALLOC_CONF=dirty_decay_ms:1000,narenas:2,background_thread:true by default. Images are published under the jiting/ruby Docker Hub namespace.

Update flow:

git fetch https://github.com/docker-library/ruby.git master:refs/remotes/upstream/master
./apply-templates.sh
git diff --exit-code

Use ./update.sh [version...] only when intentionally refreshing Ruby release metadata from ruby-lang.org.