Chapter 12. Customizing Data Grid for OpenShift

Confirm if the Data Grid for OpenShift image is available.

$ oc get images | grep jboss-datagrid73-openshift

If the image is not available, create an image stream and import it.

$ oc create -f https://raw.githubusercontent.com/jboss-container-images/jboss-datagrid-7-openshift-image/7.3-v1.9/templates/datagrid73-image-stream.json

$ oc import-image jboss-datagrid73-openshift --from='registry.redhat.io/jboss-datagrid-7/datagrid73-openshift:1.9'

Create a new binary build using the Data Grid for OpenShift image.

$ oc new-build jboss-datagrid73-openshift:1.9 --binary=true --name=custom-datagrid

Navigate to the s2i directory so you can pass --from-dir=".". You must include the configuration directory so that the S2I process can detect your custom configuration.

To use the example configuration, do the following:

$ cd jboss-datagrid-7-openshift-image/docs/examples/s2i/

Build the Data Grid for OpenShift image with your custom configuration.

$ oc start-build custom-datagrid --from-dir="." --follow

Uploading directory "." as binary input for the build ...

...
Push successful

Check that your image is available.

$ oc get images | grep custom-datagrid

Confirm that the build pod is running.

$ oc get pods

NAME                      READY     STATUS      RESTARTS   AGE
custom-datagrid-1-build   0/1       Completed   0          38s

Create a Data Grid application with your custom configuration.

$ oc new-app custom-datagrid \
  -p APPLICATION_USER=${USERNAME} \
  -p APPLICATION_PASSWORD=${PASSWORD}

Wait for your custom Data Grid application to start running.

$ oc get pods -w

NAME                      READY     STATUS         RESTARTS   AGE
custom-datagrid-1-build   0/1       Completed      0          8m
custom-datagrid-1-<id>   1/1       Running        0          11s

Remotely access the bash shell for your custom Data Grid pod.

$ oc exec -it ${pod-name} -- /bin/bash

View clustered-openshift.xml to verify the configuration, for example:

$ cat /opt/datagrid/configuration/clustered-openshift.xml

If clustered-openshift.xml contains your custom configuration then the Data Grid pod is using it. You can optionally use the Data Grid command line interface to verify your configuration, for example:

$ /opt/datagrid/bin/cli.sh -c

End the remote session after you verify your configuration.

$ exit

Wait for your custom Data Grid application to start running.

$ oc get pods -w

NAME                READY     STATUS    RESTARTS   AGE
user-config-0   0/1       Running   7          17m

Check the container logs.

$ oc logs ${pod-name} | grep standalone.xml

INFO Running jboss-datagrid-7/datagrid73-openshift image, version 1.9 with user standalone.xml

Specify the CUSTOM_INSTALL_DIRECTORIES environment variable in the image template JSON. This variable defines the location where S2I artifacts reside, as in the following example:

{
    "name": "CUSTOM_INSTALL_DIRECTORIES",
    "value": "extensions/*"
}

Create an install.sh script in that directory. This script installs the modules and drivers for the external datasource in the image.

The following is an example install.sh script:

#!/bin/bash

# Import the common functions for
# installing modules and configuring drivers
source /usr/local/s2i/install-common.sh

# Directory where this script is located
injected_dir=$1

# Install the modules for the datasource
install_modules ${injected_dir}/modules

# Configure the drivers for the datasource
configure_drivers ${injected_dir}/drivers.properties

Include a modules subdirectory that contains a module.xml file and the driver for the datasource. The resulting image uses the module to load classes and define dependencies.

As an example, you plan to use Derby as an external datasource. You need to obtain a driver such as derby-10.12.1.1.jar and place it in the following directory: modules/org/apache/derby/main/

In the same directory, you also need to create a module.xml file that defines the driver as a resource and declares dependencies.

The following is an example module.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<module xmlns="urn:jboss:module:1.3" name="org.apache.derby">
 <resources>
   <resource-root path="derby-10.12.1.1.jar"/>
   <resource-root path="derbyclient-10.12.1.1.jar"/>
 </resources>

 <dependencies>
   <module name="javax.api"/>
   <module name="javax.transaction.api"/>
 </dependencies>
</module>

Define the driver configuration properties in a drivers.property environment variable file.

The following is an example drivers.property file:

#DRIVERS
DRIVERS=DERBY

DERBY_DRIVER_NAME=derby
DERBY_DRIVER_MODULE=org.apache.derby
DERBY_DRIVER_CLASS=org.apache.derby.jdbc.EmbeddedDriver
DERBY_XA_DATASOURCE_CLASS=org.apache.derby.jdbc.EmbeddedXADataSource

After you build and deploy the image, specify environment variables for the datasource.

The following example shows a datasource definition with the DATASOURCES environment variable:

# Set a unique prefix for the datasource
DATASOURCES=ACCOUNTS_DERBY
# Specify other environment variables using the prefix
ACCOUNTS_DERBY_DATABASE=accounts
ACCOUNTS_DERBY_JNDI=java:/accounts-ds
ACCOUNTS_DERBY_DRIVER=derby
ACCOUNTS_DERBY_JTA=true
ACCOUNTS_DERBY_NONXA=false
ACCOUNTS_DERBY_USERNAME=${USERNAME}
ACCOUNTS_DERBY_PASSWORD=${PASSWORD}
ACCOUNTS_DERBY_XA_CONNECTION_PROPERTY_DatabaseName=/opt/eap/standalone/data/databases/derby/accounts
# _HOST and _PORT are required but not used
ACCOUNTS_ORACLE_HOST=dummy
ACCOUNTS_ORACLE_PORT=1527