What is the difference between 16-slim, 16-jdk-slim, 16-ea-slim docker images

Question

What is the difference between the following Docker images?

• openjdk:16-slim
• openjdk:16-jdk-slim
• openjdk:16-ea-slim

Which is smaller in size and can be used in a Spring Boot project?

Answer 1

The difference is in the Java version used and hence in the compressed size (links below):

• openjdk:16-slim of compressed size 198.93 MB uses 16.0.1
• openjdk:16-jdk-slim of compressed size 198.93 MB uses 16.0.1
• openjdk:16-ea-slim of compressed size 198.82 MB uses 16-ea+34 (early-access)

You correctly noticed there is no difference between openjdk:16-slim and openjdk:16-jdk-slim aside from hashes. I assume there are two identical images in order to respect the new naming conventions (my guess).

If you refer to the openjdk DockerHub description | Image Variants, you might find the following:

The openjdk images come in many flavors, each designed for a specific use case.

openjdk:<version>

This is the defacto image. If you are unsure about what your needs are, you probably want to use this one. It is designed to be used both as a throw away container (mount your source code and start the container to start your app), as well as the base to build other images off of.

Important: If you decide to use Spring Boot with Java 16, you need to use currently the newest version (as of May, 2021) of Spring Boot 2.5.0 or newer. Read more at Spring Boot 2.5 is now GA.