open-libertyEstimated reading time: 12 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
Supported Docker versions:
the latest release (down to 1.6 on a best-effort basis)
The images in this repository contain Open Liberty. For more information about Open Liberty, see the Open Liberty Website site.
There are multiple images 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 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:
kernel kernel-java8-ibm kernel-java8-ibmsfj microProfile1 microProfile1-java8-ibm microProfile1-java8-ibmsfj springBoot1 springBoot1-java8-ibm springBoot1-java8-ibmsfj springBoot2 springBoot2-java8-ibm springBoot2-java8-ibmsfj webProfile8 webProfile8-java8-ibm webProfile8-java8-ibmsfj javaee8 javaee8-java8-ibm javaee8-java8-ibmsfj webProfile7 webProfile7-java8-ibm webProfile7-java8-ibmsfj javaee7 javaee7-java8-ibm javaee7-java8-ibmsfj
The images are designed to support a number of different usage patterns. The following examples assume that DefaultServletEngine.zip has been extracted to
Each image contains a default server configuration that specifies the corresponding features and exposes ports 9080 and 9443 for HTTP and HTTPS respectively. A .WAR file can therefore be mounted in the
dropinsdirectory 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.
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-sfj
You can also build an application layer on top of this image by using either the default server configuration or a new server configuration. In this example, we have copied the
/tmp/DefaultServletEngine/dropinsto the same directory as the following Dockerfile.
FROM open-liberty:webProfile8 COPY Sample1.war /config/dropins/
This can then be built and run as follows:
$ docker build -t app . $ docker run -d -p 80:9080 -p 443:9443 app
You can mount a data volume container that contains the application and the server configuration on to the image. This has the benefit that it has no dependency on files from the host but still allows the application container to be easily re-mounted on a newer version of the application server image. This example assumes that you have copied the
/tmp/DefaultServletEnginedirectory in to the same directory as the Dockerfile.
Build and run the data volume container:
FROM open-liberty:webProfile8 COPY DefaultServletEngine /config
$ docker build -t app-image . $ docker run -d -v /config \ --name app app-image true
Run the Open Liberty image with the volumes from the data volume container mounted:
$ docker run -d -p 80:9080 \ --volumes-from app 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. The following example starts a container running a Spring Boot application.
$ docker run -d -p 8080:9080 \ -v /tmp/hellospringboot.jar:/config/dropins/spring/hellospringboot.jar \ open-liberty:springBoot2
Similarly, 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 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.
For example, run the following command to thin the
$ <wlp>/bin/springBootUtility thin \ --sourceAppPath=/tmp/hellospringboot.jar \ --targetLibCachePath=/tmp/lib.index.cache \ --targetThinAppPath=/tmp/thinhellospringboot.jar
You can run the thin application by mounting both the target application JAR and library cache when starting the container.
$ docker run -d -p 8080:9080 \ -v /tmp/thinhellospringboot.jar:/config/dropins/spring/thinhellospringboot.jar \ -v /tmp/lib.index.cache:/lib.index.cache \ open-liberty:springBoot2
Similarly, 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 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 `/opt/ol` rather than `/opt/ibm`. Use the `/config` folder for accessing the server configuration. Use the `/output` folder for accessing the server output. When adding your own SSL configuration use the `/config/configDropins/defaults/keystore.xml`.
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