• 8-jre, jre, 8, latest (ibmjava/8-jre/x86_64/ubuntu/Dockerfile)
• 8-jre-alpine, jre-alpine (ibmjava/8-jre/x86_64/alpine/Dockerfile)
• 8-sfj, sfj (ibmjava/8-sfj/x86_64/ubuntu/Dockerfile)
• 8-sfj-alpine, sfj-alpine (ibmjava/8-sfj/x86_64/alpine/Dockerfile)
• 8-sdk, sdk (ibmjava/8-sdk/x86_64/ubuntu/Dockerfile)

For more information about this image and its history, please see the relevant manifest file (library/ibmjava). This image is updated via pull requests to the docker-library/official-images GitHub repo.

For detailed information about the virtual/transfer sizes and individual layers of each of the above supported tags, please see the repos/ibmjava/tag-details.md file in the docker-library/repo-info GitHub repo.

The images in this repository contain IBM® SDK, Java™ Technology Edition, version 1.8.0_sr3fp21 (8.0-3.21). See what's new. See the license section for restrictions that relate to the use of this image. For more information about IBM® SDK, Java™ Technology Edition and API documentation, see the IBM Knowledge Center. For tutorials, recipes, and Java usage in Bluemix, see IBM developerWorks.

Java and all Java-based trademarks and logos are trademarks or registered trademarks of Oracle and/or its affiliates.

There are three types of Docker images here: the Software Developers Kit (SDK), and the Java Runtime Environment (JRE) and a small footprint version of the JRE (SFJ). These images can be used as the basis for custom built images for running your applications.

The Small Footprint JRE (SFJ) is designed specifically for web developers who want to develop and deploy cloud-based Java applications. Java tools and functions that are not required in the cloud environment, such as the Java control panel, are removed. The runtime environment is stripped down to provide core, essential function that has a greatly reduced disk and memory footprint.

Consider using Alpine Linux if you are concerned about the size of the overall image. Alpine Linux is a stripped down version of Linux that is based on musl libc and Busybox, resulting in a Docker image size of approximately 5 MB. Due to its extremely small size and reduced number of installed packages, it has a much smaller attack surface which improves security. However, because the IBM SDK has a dependency on gnu glibc, installing this library adds an extra 8 MB to the image size. The following table compares Docker Image sizes based on the JRE version 8.0-3.10.

Note: Alpine Linux is not an officially supported operating system for IBM® SDK, Java™ Technology Edition.

Docker Images for the following architectures are now available:

• x86_64
• ppc64le
• s390x

To run a pre-built jar file with the JRE image, use the following commands:

FROM ibmjava:jre
RUN mkdir /opt/app
COPY japp.jar /opt/app
CMD ["java", "-jar", "/opt/app/japp.jar"]

You can build and run the Docker Image as shown in the following example:

docker build -t japp .
docker run -it --rm japp

If you want to place the jar file on the host file system instead of inside the container, you can mount the host path onto the container by using the following commands:

FROM ibmjava:jre
CMD ["java", "-jar", "/opt/app/japp.jar"]

docker build -t japp .
docker run -it -v /path/on/host/system/jars:/opt/app japp

IBM SDK, Java Technology Edition provides a feature called Class data sharing. This mechanism offers transparent and dynamic sharing of data between multiple Java virtual machines (JVMs) running on the same host thereby reducing the amount of physical memory consumed by each JVM instance. By providing partially verified classes and possibly pre-loaded classes in memory, this mechanism also improves the start up time of the JVM.

To enable class data sharing between JVMs that are running in different containers on the same host, a common location must be shared between containers. This requirement can be satisfied through the host or a data volume container. When enabled, class data sharing creates a named "class cache", which is a memory-mapped file, at the common location. This feature is enabled by passing the -Xshareclasses option to the JVM as shown in the following Dockerfile example:

FROM ibmjava:jre
RUN mkdir /opt/shareclasses
RUN mkdir /opt/app
COPY japp.jar /opt/app
CMD ["java", "-Xshareclasses:cacheDir=/opt/shareclasses", "-jar", "/opt/app/japp.jar"]

The cacheDir sub-option specifies the location of the class cache. For example /opt/sharedclasses. When sharing through the host, a host path must be mounted onto the container at the location the JVM expects to find the class cache. For example:

docker build -t japp .
docker run -it -v /path/on/host/shareclasses/dir:/opt/shareclasses japp

When sharing through a data volume container, create a named data volume container that shares a volume.

docker create -v /opt/shareclasses --name classcache japp /bin/true

Then start your JVM container by using --volumes-from flag to mount the shared volume, as shown in the following example:

docker run -it --volumes-from classcache japp

See the Websphere-Liberty image, which builds on top of this IBM docker image for Java.

The Dockerfiles and associated scripts are licensed under the Apache License 2.0.

Licenses for the products installed within the images:

• IBM® SDK, Java™ Technology Edition: [International License Agreement for Non-Warranted Programs](http://www14.software.ibm.com/cgi-bin/weblap/lap.pl?la_formnum=&li_formnum=L-PMAA-A3Z8P2&title=IBM® SDK, Java™ Technology Edition Docker Image, Version 8.0&l=en).

This image is officially supported on Docker version 1.12.4.

Support for older versions (down to 1.6) is provided on a best-effort basis.

Please see the Docker installation documentation for details on how to upgrade your Docker daemon.

For issues relating specifically to this Docker image, please use the GitHub issue tracker.

For more general issues relating to IBM® SDK, Java™ Technology Edition you can ask questions in the developerWorks forum: IBM Java Runtimes and SDKs.

For general information on Troubleshooting with the SDK, please do take a look at our How Do I ...? page.