Java Docker Images

OpenJDK Docker Images built and maintained by XeniT

• Using Eclipse Temurin for Java 8 and later.
• Using Oracle OpenJDK from the Ubuntu or CentOS distributions for legacy JDK 7.

Supported Tags

• jdk-11-ubuntu-18.04, jdk-11-bionic, jdk-11
• jdk-11-ubuntu-20.04, jdk-11-focal
• jdk-8-ubuntu-18.04, jdk-8-bionic, jdk-8-ubuntu, jdk-8
• jdk-7-ubuntu-14.04, jdk-7-trusty

Alfresco Compatible Tags

• JDK 11: alfresco-6.0-ubuntu, alfresco-6.1-ubuntu, alfresco-6.2-ubuntu
• JDK 8: alfresco-5.0-ubuntu, alfresco-5.1-ubuntu, alfresco-5.2-ubuntu
• JDK 7: alfresco-4.2-ubuntu, jdk-7u211-ubuntu-14.04, jdk-7-ubuntu-14.04

Additional tags are provided:

• images are also tagged with the exact JDK version (for example jdk-8u312-bionic), but these tags will not receive future updates.
• tags containing a -SNAPSHOT postfix are development artifacts (automated builds from the master branch).
• tags without any postfix are release artifacts

Environment variables

There are several environment variables available to tweak the behaviour. While none of the variables are required, they may significantly aid you in using these images. The variables are read by an init script which further appends to JAVA_OPTS.

Environment variables:

Variable	Default	Java variable
JAVA_XMS		-Xmx
JAVA_XMX		-Xms
DEBUG	false	-Xdebug -Xrunjdwp:transport=dt_socket,address=8000,server=y,suspend=n
JMX_ENABLED	false	-Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.local.only=false -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.rmi.port=5000 -Dcom.sun.management.jmxremote.port=5000 -Djava.rmi.server.hostname=$JMX_RMI_HOST
JMX_RMI_HOST	0.0.0.0
JAVA_OPTS_<variable>=<value>	<value>	<variable>

Quick reference

Where to get help:

Channel #xeniteu/docker on Gitter

Maintained by:

XeniT docker@xenit.eu

Supported Architectures:

• linux-x64

Supported Docker versions:

• down to 1.10 (on a best-effort basis)

Environment Variables

The docker.io/xenit/openjdk image supports the following environment variables:

JAVA_OPTS_xxx

This image iterates over all environment variables that start with JAVA_OPTS_ and collects them into the environment variable JAVA_OPTS when the container is started. This JAVA_OPTS variable can be used to pass JVM arguments to the java process.

The environment variable should have the format JAVA_OPTS_xxx="-Dkey=value", where the key xxx is ignored.

Note: This ignored key can be useful, when you want to override a particular JVM argument when using multiple docker-compose.yml files or docker-compose.override.yml. See the Docker Compose documentation for more information.

Image variants

The openjdk images come in a few flavors, where the variants use the following tag-structure:

openjdk:<type>-<version>-<os>

There are permutations possible of three parameters in this project.

• Type: the Java distribution type, one of jdk, jre or server-jre. At the moment only jdk is supported.
• Version: the Java version, for example 8u312
• OS: the Operating system, for example ubuntu-18.04, with optionally some additional variants

Please file an issue if you need a different combination of parameters.

Java versions

In general, the latest update of the LTS-releases are maintained.

NOTE: the Java update (=minor version) is NOT maintained. For example: the current Ubuntu JDK 8 image is tagged with jdk-8-ubuntu-18.04 and has the additional tag jdk-8u312-ubuntu-18.04 to indicate the Java 8 update version. Once the next update is published, the image tagged jdk-8-ubuntu-18.04 will be updated, but jdk-8u312-ubuntu-18.04 will no longer be supported and will not receive OS or Java security patches.

Images are used as base images for Alfresco services.

When the OS reached end-of-life (Alfresco 4 - using Ubuntu 10.04, 12.04), next available LTS version is used. When multiple major Java versions are supported, the higher version is used. Java update is always the latest one available.

At the moment, following versions are built:

Alfresco	OpenJDk	Ubuntu
Alfresco 6.2	JDK 11u13	18.04 - jdk-11-ubuntu-18.04
Alfresco 6.1	JDK 11u13	18.04 - jdk-11-ubuntu-18.04
Alfresco 6.0	JDK 11u13	18.04 - jdk-11-ubuntu-18.04
Alfresco 5.2	JDK 8u312	18.04 - jdk-8-ubuntu-18.04
Alfresco 5.1	JDK 8u312	18.04 - jdk-8-ubuntu-18.04
Alfresco 5.0	JDK 8u312	18.04 - jdk-8-ubuntu-18.04
Alfresco 4.2	JDK 7u211 (Oracle)	14.04 - jdk-7-ubuntu-14.04

Operating Systems

• Ubuntu 20.04 LTS - ubuntu:focal
• Ubuntu 18.04 LTS - ubuntu:bionic
• Ubuntu 14.04 LTS - ubuntu:trusty

Initialization

This image uses Docker ENTRYPOINT to provide initialization hooks.

If you would like to do additional initialization in an image derived from this one, add one or more *.sh scripts under /docker-entrypoint.d/. The scripts are source'd and do not need to be executable. This means these scripts run within the existing shell, any variables created or modified by the script will remain available after the script completes. These initialization scripts will be executed in sorted name order as defined by the current locale.

After initialization completes, the main CMD will be exec'ed, to avoid starting the main process in a subshell.

You can override or disable the initialization scripts by overriding the ENTRYPOINT instruction using the docker run --entrypoint flag.

Contributions

How to build

Builds are produced by GitHub Actions driving Gradle from a GitHub workflow file.

To build a local version of the java image:

./gradlew buildDockerImage

FAQ

How do I access the Java debug port?

Set the environment variable DEBUG=true. The debug port is 8000.

How do I enable JMX?

Set the environment variable JMX_ENABLED=true. The JMX port is 5000.