Docker Course Labs

Lab Solution

Search for java on Docker Hub and the official image is the top hit.

You might start by downloading the Java package:

docker pull java

Run a container to check the Java version:

docker run java java -version

And then the JRE build for Alpine is the smallest:

docker pull java:8-jre-alpine
docker image ls java

Latest is 640MB; 8 JRE is 100MB but both 4 years old...

Using OpenJDK

The official Java page on Docker Hub is actually a redirect to the OpenJDK package, which is an open-source Java runtime.

But the java package is not the same as openjdk - and you should use openjdk because it's more up-to-date:

docker pull openjdk
docker pull openjdk:8-jre-alpine

The default image tag is much more recent, and both images are smaller:

docker image ls openjdk