This is a simple Web Archive (WAR) application to demonstrate deployments with OpenShift.

The application's root context is /hello

A curl-friendly hostname checker is available at /hello/host

It leverages several features from OpenShift's S2I build strategy, which allows images to be built directly from source code, using the base image jboss-eap72-openshift:1.1 from Red Hat. Their base image includes built-in scripting that allows several core EAP configurations to be dynamically configured at runtime.

This project contains several folders not found in a typical Maven project. The jboss-eap72-openshift automatically scans for and places contents of these folders into specific EAP locations.

• modules/* gets placed in $JBOSS_HOME/modules
• configuration/* copied to $JBOSS_HOME/standalone/configuration
• deployments/* copied to $JBOSS_HOME/standalone/deployments

Also note that standalone-openshift.xml replaces the default standalone.xml when running within OpenShift. The OpenShift version is configured to do discovery and networking with OpenShift in mind, and probably won't work with other PaaS systems.

This application relies on having a database available. Since we're running on OpenShift, I instantiated an emphermal MariaDB database, and used the SQL script mariadb-sample.sql to configure and populate the database with sample data. You can use an existing database, but the values in the examples below will need to be adjusted accordingly.

A folder named extensions is provided that contains some jboss-cli scripts to dynamically configure JDBC Drivers for use with Datasources.

You can just run it via oc with the files provided in the extensions folder of this repo.

 oc create configmap jboss-cli --from-file=postconfigure.sh=extensions/postconfigure.sh --from-file=extensions.cli=extensions/extensions.cli

And then add it to your DeploymentConfig. Don't forget to change hello-openshift to the actual name of your DeploymentConfig.

oc set volume dc/hello-openshift --add --name=jboss-cli -m /opt/eap/extensions -t configmap --configmap-name=jboss-cli --default-mode='0755' --overwrite

There's nothing special about it, it just creates a ConfigMap with data that looks like this. Look in the extensions folder to see for yourself.

  extensions.cli: |
    embed-server --std-out=echo  --server-config=standalone-openshift.xml
    /subsystem=datasources/jdbc-driver=mariadb:add(driver-name=mariadb,driver-module-name=org.mariadb,driver-xa-datasource-class-name=org.mariadb.jdbc.MariaDbDataSource,driver-class-name=org.mariadb.jdbc.Driver)
    quit
  postconfigure.sh: |
    #!/usr/bin/env bash
    set -x
    echo "Executing postconfigure.sh"
    $JBOSS_HOME/bin/jboss-cli.sh --file=$JBOSS_HOME/extensions/extensions.cli

When the pod restarts, you should see similar output at the top of the logs.

+ echo 'Executing postconfigure.sh'
Executing postconfigure.sh
+ /opt/eap/bin/jboss-cli.sh --file=/opt/eap/extensions/extensions.cli
�[0m14:07:08,597 INFO  [org.jboss.modules] (CLI command executor) JBoss Modules version 1.8.8.Final-redhat-00001
�[0m�[0m14:07:08,898 INFO  [org.jboss.msc] (CLI command executor) JBoss MSC version 1.4.5.Final-redhat-00001
�[0m�[0m14:07:08,908 INFO  [org.jboss.threads] (CLI command executor) JBoss Threads version 2.3.2.Final-redhat-1
�[0m�[0m14:07:09,498 INFO  [org.jboss.as] (MSC service thread 1-2) WFLYSRV0049: JBoss EAP 7.2.3.GA (WildFly Core 6.0.15.Final-redhat-00001) starting

Here are two options for configuring datasources dynamically.

You can dynamcially create Datasources at runtime by injecting Environment variables into your Deployment/DeploymentConfig. The settings can be added via single values (env), or as all values from a ConfigMap or Secret.

These are sample properties that a ConfigMap would need in order to configure a datasource.

data:
  DB_SERVICE_PREFIX_MAPPING: example-mariadb=DS1
  DS1_DRIVER: mariadb
  DS1_JNDI: 'java:/example'
  DS1_URL: jdbc:mariadb://mariadb.<namespace>.svc.cluster.local:3306/test
  DS1_DATABASE: test
  DS1_USERNAME: user
  DS1_PASSWORD: password
  DS1_CONNECTION_CHECKER: org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLValidConnectionChecker
  DS1_EXCEPTION_SORTER: org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLExceptionSorter
  DS1_NONXA: "true"
  EXAMPLE_MARIADB_SERVICE_PORT: '3306'
  EXAMPLE_MARIADB_SERVICE_HOST: mariadb.<namespace>.svc.cluster.local

And here's a PostgreSQL example if you don't want to just use the default drivers.

data:
  DB_SERVICE_PREFIX_MAPPING: example-psql=DS1
  DS1_DRIVER: postgresql
  DS1_JNDI: 'java:/example'
  DS1_URL: jdbc:postgresql://postgresql.<namespace>.svc.cluster.local:5432/test
  DS1_DATABASE: test
  DS1_USERNAME: user
  DS1_PASSWORD: password
  DS1_CONNECTION_CHECKER: org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLValidConnectionChecker
  DS1_EXCEPTION_SORTER: org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLExceptionSorter
  DS1_NONXA: "true"
  EXAMPLE_MARIADB_SERVICE_PORT: '5432'
  EXAMPLE_MARIADB_SERVICE_HOST: postgresql.<namespace>.svc.cluster.local

Note that you can only use one or the other. Both examples are configured to use the same java:/example JNDI name, so you have to give them both unique names, or just use one of them. The code is only looking for java:/example.

The implementation of this has some subtle differences. Note the use of the DATASOURCES property, whereas the other method uses DB_SERVICE_PREFIX_MAPPING to create "short" names for the ENV properties.

These are sample properties that a Secret would need in order to configure a datasource. Note the key is the name of the file, which is in properties file format, not YAML.

DATASOURCES=DS1
DS1_JNDI=java:/example
DS1_DRIVER=mariadb
DS1_USERNAME=user
DS1_PASSWORD=password
DS1_MAX_POOL_SIZE=20
DS1_MIN_POOL_SIZE=10
DS1_CONNECTION_CHECKER=org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLValidConnectionChecker
DS1_EXCEPTION_SORTER=org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLExceptionSorter
DS1_URL=jdbc:mariadb://mariadb.<namespace>.svc.cluster.local:3306/test
DS1_NONXA=true

Note: For whatever reason, each line of my properties file started with two spaces when I cut and pasted. Make sure you remove those spaces so everything is left-aligned.

You'll need to project this Secret as a volume into your container. The location doesn't really matter, but don't override any critical folders required for EAP to function properly. I followed previous examples and projected it into /etc/extensions.

Finally, set the ENV_FILES ENV variable, which takes a comma-separated list if you projected your Datasources into multiple volumes. If you have a single Secret that contains multiple files, you will need to list out all the files to be processed.

Everything I've demonstrated so far has been for dynamic configurations, but you'll also notice that I provided a configuration/standalone-openshift.xml file. You can always statically configure EAP by passing in your own file. The example configuration is the default jboss-eap72-openshift:1.1's configuration file, so make sure you always use the latest version specific to your image.

You can use both static and dynamic configuration methods to fine tune your EAP instance. Pass in your own standalone-openshift.xml file and use ENV variables or custom jboss-cli scripts to configure EAP the way that you need it.

Note the placeholders throughout standalone-openshift.xml such as <!-- ##DATASOURCES## --> and <!-- ##ELYTRON_KEY_STORE## -->. These are markers where the EAP base image inject calculated values, which are derived dynamically via built-in scripting.

You can easily modify the existing standalone-openshift.xml with other runtime configurations with expression evalulations. Through the configuration file, just reference an ENV variable with the env. prefix, and provide default values as needed. This project has a sample setting for the logging level. Set the ENV variable CUSTOM_LOG_LEVEL anywhere you choose to override the default value of INFO. It would look like the following in the XML - ${env.CUSTOM_LOG_LEVEL:INFO}.

Note that not all properties in the XML support expressions. A field like the data-source pool-name needs a static name that cannot be configured at runtime.