The UBI OpenJDK containers are full fat developer containers:
they've got the full OpenJDK distribution in them (including
they include Maven and there are various quality-of-life additions such as a
Prometheus agent for metrics gathering in OpenShift and a
run-java script to
control launching the eventual application, as well as OpenShift
Source-To-Image (S2I) integration.
We've had a number of customers request that we produce some runtime-only images. It took a while to properly scope the request, as each person who wanted such a thing wanted a different subset of functionality included from the existing images. One consistent request though related to image size: It became clear that the runtime images should be as minimal as possible.
Last week we launched ubi8/openjdk-8-runtime and ubi8/openjdk-11-runtime containers which weight in at
106.M1iB and 119.7 MiB respectively. They are extremely bare-bones, containing
just a subset of the OpenJDK distribution (that which is packaged as
java-N-openjdk-headless in RHEL)
on top of the UBI minimal flavour base images.
To explain one way these could be use in an OpenShift environment I wrote a blog post for Red Hat Developer: Build lean Java containers with the new Red Hat Universal Base Images OpenJDK runtime images.
We've got a couple of avenues under exploration in this area which should result in even leaner or more tailored images in the future. I'll write more when we have something to show!