JVM 8 and Docker

JVM 1.8u181 info inside Docker container

Prerequirements

• Maven
• Docker

Build

Create jar and Docker images

mvn clean install

This will produce Spring Boot application with a singe REST enpoint /jvm, showing JVM and environment info

Produced images are:

• cnj/openjdk-jvm-info: image based on openjdk:8u181-jdk-slim-stretch
• cnj/fabric8-jvm-info: image based on fabric8/java-centos-openjdk8-jdk

Why 2 images? In order to compare how fabric8 overcome limitations of JVM 8 inside Docker.

Run

This project use Docker stacks. Enter Swarm mode

docker swarm init

Then run OpenJDK

docker stack deploy -c src/docker/openjdk/stack.yml openjkd-jvm

And go to http://localhost:8080/jvm

Compare what declared in src/docker/openjdk/stack.yml with result of http://localhost:8080/jvm: number of core will never match due to a bug fixed in version 10

For Fabric8 version

docker stack deploy -c src/docker/openjdk/stack.yml openjkd-jvm

And go to http://localhost:8081/jvm