open-libertyEstimated reading time: 15 minutes
Official Open Liberty image.
GitHub repo: https://github.com/OpenLiberty/ci.docker
Supported tags and respective
Where to get help:
the Open Liberty community
Where to file issues:
the Open Liberty Community
The images in this repository contain Open Liberty. For more information about Open Liberty, see the Open Liberty Website site.
This image runs by default with
USER 1001 (non-root), as part of group
0. Please make sure you read below to set the appropriate folder and file permissions.
Updating folder permissions
All of the folders accessed by Open Liberty have been given the appropriate permissions, but if your extending Dockerfile needs permission to another location you can simply temporarily switch into root and provide the needed permissions, example:
USER root RUN mkdir -p /myFolder && chown -R 1001:0 /myFolder USER 1001
Updating file permissions
You have to make sure that all the artifacts you are copying into the image (via
ADD) have the correct permissions to be
executed by user
1001 or group
0, because the ownership of the file is changed to be
root:0 when transferring into the docker image.
You have a few options for doing this: before copying the file, during copy, or after copy.
Updating permissions before copying
Since the ownership of the file will change to
root:0, you can simply set the permissions for the owner’s group to be able to read/execute the artifact (i.e. the middle digit of a
chmod command). For example, you can do
chmod g+rx server.xml to ensure your
server.xml can be
executed by group
0, as well as any artifacts such as the application’s
WAR file, JDBC driver, or other files that are placed on the image via
Updating permissions during copy
If you’re using Docker v17.09.0-ce and newer you can take advantage of the flag
--chown=<user>:<group> during either
COPY. For example:
COPY --chown=1001:0 jvm.options /config/jvm.options. This is the preferred approach as you don’t need to worry about changing permissions before calling
docker build and you also do not duplicate layers in the resulting image.
Updating permissions after copy
If you need your Dockerfile to work with older versions of Docker CE and don’t want to pre-process the permissions of the files you can temporarily switch into root to change the permissions of the needed files. For example:
USER root RUN chown 1001:0 /config/jvm.options RUN chown 1001:0 /output/resources/security/ltpa.keys USER 1001
Please note that this pattern will duplicate the docker layers for those artifacts, which can heavily bloat your resulting docker image (depending on the size of the artifact). So it is recommended to set the permissions before or during copy.
There are multiple tags available in this repository.
kernel image contains the Liberty kernel and can be used as the basis for custom built images that contain only the features required for a specific application. For example, the following Dockerfile starts with this image, copies in the
server.xml that lists the features required by the application.
FROM open-liberty:kernel COPY --chown=1001:0 Sample1.war /config/dropins/ COPY --chown=1001:0 server.xml /config/
microProfile1 image contains the features required to implement Eclipse MicroProfile 1.3. The
webProfile8 image contains the features required for Java EE8 Web Profile compliance. The
javaee8 image adds the features required for Java EE8 Full Platform compliance. The
javaee8 image is also tagged with
webProfile7 image contains the features required for Java EE7 Web Profile compliance. The
javaee7 image adds the features required for Java EE7 Full Platform compliance. The
springBoot2 images contain the features required for running Spring Boot 1.5 and 2.0 applications.
There are also additional images for different JVM combinations. Currently there are tags for java8 only, but there are two variants one based on IBM Java and Ubuntu and the other based on the IBM small footprint Java which is based on alpine linux. The naming structure for the variants is tag-javaversion-vandor/variant. This leads to webProfile8-java8-ibmsfj as one. At this time the full list of images are found in the
Supported tags and respective Dockerfile links section above.
The images are designed to support a number of different usage patterns. The following examples are based on the Java EE8 Liberty application deployment sample and assume that DefaultServletEngine.zip has been extracted to
/tmp and the
server.xml updated to accept HTTP connections from outside of the container by adding the following element inside the
server stanza (if not using one of the pre-packaged
server.xml files with our tags):
<httpEndpoint host="*" httpPort="9080" httpsPort="-1"/>
It is a very strong best practice to create an extending Docker image, we called it the
application image, that encapsulates an application and its configuration. This creates a robust, self-contained and predictable Docker image that can span new containers upon request, without relying on volumes or other external runtime artifacts that may behave different over time.
If you want to build the smallest possible WebSphere Liberty application image you can start with our
kernel tag, add your artifacts, and run
configure.sh to grow the set of features to be fit-for-purpose. Please see our GitHub page for more details.
Enabling Enterprise functionality
The Open Liberty images have a set of built-in XML snippets that enable and configure enterprise functionality such as session cache and monitoring. These are toggled by specific
ARGs in your application image Dockerfile and configured via the
configure.sh script. Please see the instructions on our GitHub page for more information.
Using volumes for configuration
This pattern can be useful for quick experiments / early development (i.e.
I just want to run the application as I iterate over it), but should not be used for development scenarios that involve different teams and environments - for these cases the
Application Image pattern described above is the way to go.
volumes, an application file can be mounted in the
dropins directory of this server and run. The following example starts a container in the background running a .WAR file from the host file system with the HTTP and HTTPS ports mapped to 80 and 443 respectively.
$ docker run -d -p 80:9080 -p 443:9443 \ -v /tmp/DefaultServletEngine/dropins/Sample1.war:/config/dropins/Sample1.war \ open-liberty:webProfile8
When the server is started, you can browse to http://localhost/Sample1/SimpleServlet on the Docker host.
Note: If you are using the boot2docker virtual machine on OS X or Windows, you need to get the IP of the virtual host by using the command
boot2docker ip instead of by using localhost.
For greater flexibility over configuration, it is possible to mount an entire server configuration directory from the host and then specify the server name as a parameter to the run command. Note: This particular example server configuration provides only HTTP access.
$ docker run -d -p 80:9080 \ -v /tmp/DefaultServletEngine:/config \ open-liberty:webProfile8
springBoot images introduce capabilities specific to the support of Spring Boot applications, including the
springBootUtility used to separate Spring Boot applications into thin applications and dependency library caches. To elaborate these capabilities this section assumes the standalone Spring Boot 2.0.x application
hellospringboot.jar exists in the
A Spring Boot application JAR deploys to the
dropins/springdirectory within the default server configuration, not the
dropinsdirectory. Liberty allows one Spring Boot application per server configuration. You can create a Spring Boot application layer over this image by adding the application JAR to the
dropins/springdirectory. In this example we copied
/tmpto the same directory containing the following Dockerfile.
FROM open-liberty:springBoot2 COPY --chown=1001:0 hellospringboot.jar /config/dropins/spring/
The custom image can be built and run as follows.
$ docker build -t app . $ docker run -d -p 8080:9080 app
springBootimages provide the library cache directory,
lib.index.cache, which contains an indexed library cache created by the
lib.index.cacheto provide the library cache for a thin application.
You can use the
springBootUtilitycommand to create thin application and library cache layers over a
springBootimage. The following example uses docker staging to efficiently build an image that deploys a fat Spring Boot application as two layers containing a thin application and a library cache.
FROM open-liberty:springBoot2 as staging COPY --chown=1001:0 hellospringboot.jar /staging/myFatApp.jar RUN springBootUtility thin \ --sourceAppPath=/staging/myFatApp.jar \ --targetThinAppPath=/staging/myThinApp.jar \ --targetLibCachePath=/staging/lib.index.cache FROM open-liberty:springBoot2 COPY --from=staging /staging/lib.index.cache /lib.index.cache COPY --from=staging /staging/myThinApp.jar /config/dropins/spring/myThinApp.jar
For Spring Boot applications packaged with library dependencies that rarely change across continuous application updates, you can use the capabilities mentioned above to to share library caches across containers and to create even more efficient docker layers that leverage the docker build cache.
Providing your own keystore/truststore
open-liberty image starts, it can generate a Liberty server XML snippet in
/config/configDropins/defaults/keystore.xml that specifies a
keyStore stanza with a generated password. This causes Open Liberty to generate a default keystore and truststore with a self-signed certificate when it starts. Images can request this by setting:
ENV KEYSTORE_REQUIRED "true"
When providing your own keystore/truststore, this default behavior can be disabled by adding:
ENV KEYSTORE_REQUIRED "false"
It is good practice to place the keystore customization in
/config/configDropins/defaults/keystore.xml even when not generated since this makes it easier to find and makes moving to the websphere-liberty docker image simpler.
Using IBM JRE Class data sharing
The IBM JRE provides a feature Class data sharing which offers transparent and dynamic sharing of data between multiple Java Virtual Machines running on the same host by using shared memory backed by a file. When running the Liberty Docker image, it looks for the file at
/opt/ol/wlp//output/.classCache. To benefit from Class data sharing, this location needs to be shared between containers either through the host or a data volume container.
Taking the application image from example 3 above, containers can share the host file location (containing the shared cache)
/tmp/open-liberty/classCache as follows:
docker run -d -p 80:9080 -p 443:9443 \ -v /tmp/open-liberty/classCache:/opt/ol/wlp/output/.classCache app
Or, create a named data volume container that exposes a volume at the location of the shared file:
docker run -v /opt/ol/wlp//output/.classCache \ --name classcache open-liberty true
Then, run the Open Liberty image with the volumes from the data volume container classcache mounted as follows:
docker run -d -p 80:9080 -p 443:9443 --volumes-from classcache app
Running Open Liberty in read-only mode
Liberty writes to two different directories when running:
/logs. In order to run the Liberty image in read-only mode these may be mounted as temporary file systems. If using the provided image, the keystore will be generated on initial start up in the server configuration. This means that the server configuration directory either needs to be read-write or the keystore will need to be built into the image. In the example command
/config is mounted as a read-write volume.
docker run -d -p 80:9080 -p 443:9443 \ --tmpfs /opt/ol/wlp//output --tmpfs /logs -v /config --read-only \ open-liberty:webProfile8
Relationship between Open Liberty and WebSphere Liberty
WebSphere Liberty is a commercial distribution of Open Liberty. There is an official docker image for websphere-liberty. The websphere-liberty docker image predates the open-liberty one, so to make it simpler to move from open-liberty to websphere-liberty (or vice versa) the images are broadly compatible. It should be possible to move from one to the other with a simple FROM clause change. Some considerations for moving between them:
- Open Liberty installs into
- Use the
/configfolder for accessing the server configuration.
- Use the
/outputfolder for accessing the server output.
- When adding your own SSL configuration use the
View license information for the software contained in this image.
As with all Docker images, these likely also contain other software which may be under other licenses (such as Bash, etc from the base distribution, along with any direct or indirect dependencies of the primary software being contained).
Some additional license information which was able to be auto-detected might be found in the
As for any pre-built image usage, it is the image user’s responsibility to ensure that any use of this image complies with any relevant licenses for all software contained within.library, sample, open-liberty