Chapter 5. Capability Trimming in JBoss EAP for OpenShift

Procedure

1. To create a new Maven project, run the following command:

   mvn archetype:generate -DarchetypeGroupId=org.codehaus.mojo.archetypes -DarchetypeArtifactId=pom-root -DgroupId=org.example.mariadb -DartifactId=mariadb-galleon-pack -DinteractiveMode=false

2. In the directory mariadb-galleon-pack, update the pom.xml file to include the Red Hat Maven repository:

   <repositories>
     <repository>
       <id>redhat-ga</id>
       <name>Redhat GA</name>
       <url>https://maven.repository.redhat.com/ga/</url>
     </repository>
   </repositories>

3. Update the pom.xml file to add dependencies on the EAP Galleon feature-pack and the MariaDB driver:

   <dependencies>
     <dependency>
       <groupId>org.jboss.eap</groupId>
       <artifactId>wildfly-ee-galleon-pack</artifactId>
       <version>7.4.4.GA-redhat-00011</version>
       <type>zip</type>
     </dependency>
     <dependency>
        <groupId>org.mariadb.jdbc</groupId>
        <artifactId>mariadb-java-client</artifactId>
        <version>3.0.5</version>
     </dependency>
   </dependencies>

4. Update the pom.xml file to include the Maven plugin that is used to build the Galleon feature-pack:

   <build>            
       <plugins>
            <plugin>
                <groupId>org.wildfly.galleon-plugins</groupId>
                <artifactId>wildfly-galleon-maven-plugin</artifactId>
                <version>5.2.11.Final</version>
                <executions>
                    <execution>
                        <id>mariadb-galleon-pack-build</id>
                        <goals>
                            <goal>build-user-feature-pack</goal>
                        </goals>
                        <phase>compile</phase>
                    </execution>
                </executions>
            </plugin>
       </plugins>
   </build>

Procedure

1. Create the directory, src/main/resources, within a custom feature-pack Maven project, for example, see Preparing the Maven project. This directory is the root directory containing the feature-pack content.
2. Create the directory src/main/resources/modules/org/mariadb/jdbc/main.

3. In the main directory, create a file named module.xml with the following content:

   <?xml version="1.0" encoding="UTF-8"?>
   <module name="org.mariadb.jdbc" xmlns="urn:jboss:module:1.8">
      <resources>
          <artifact name="${org.mariadb.jdbc:mariadb-java-client}"/> 1
      </resources>
      <dependencies> 2
          <module name="javax.api"/>
          <module name="javax.transaction.api"/>
      </dependencies>
   </module>

   1

   The MariaDB driver groupId and artifactId. At provisioning time, the actual driver jar file gets installed. The version of the driver is referenced from the pom.xml file.

   2

   The JBoss Modules modules dependencies for the MariaDB driver.

4. Create the directory src/main/resources/layers/standalone/. This is the root directory of all the layers that the Galleon feature-pack is defining.
5. Create the directory src/main/resources/layers/standalone/mariadb-driver.

6. In the mariadb-driver directory, create the layer-spec.xml file with the following content:

   <?xml version="1.0" ?>
   <layer-spec xmlns="urn:jboss:galleon:layer-spec:1.0" name="mariadb-driver">
    <feature spec="subsystem.datasources"> 1
          <feature spec="subsystem.datasources.jdbc-driver">
                <param name="driver-name" value="mariadb"/>
                <param name="jdbc-driver" value="mariadb"/>
                <param name="driver-xa-datasource-class-name" value="org.mariadb.jdbc.MariaDbDataSource"/>
                <param name="driver-module-name" value="org.mariadb.jdbc"/>
          </feature>
    </feature>
    <packages> 2
          <package name="org.mariadb.jdbc"/>
    </packages>
   </layer-spec>

   1

   Update the datasources subsytem configuration with a JDBC-driver named MariaDB, implemented by the module org.mariadb.jdbc.

   2

   The JBoss Modules module containing the driver classes that are installed when the layer is provisioned.

   The mariadb-driver layer updates the datasources subsystem with the configuration of a JDBC driver, implemented by the JBoss Modules module.

7. Create the directory src/main/resources/layers/standalone/mariadb-datasource.

8. In the mariadb-datasource directory, create the layer-spec.xml file with the following content:

   <?xml version="1.0" ?>
   <layer-spec xmlns="urn:jboss:galleon:layer-spec:1.0" name="mariadb-datasource">
   <dependencies>
        <layer name="mariadb-driver"/> 1
   </dependencies>
       
   <feature spec="subsystem.datasources.data-source"> 2
          <param name="data-source" value="MariaDBDS"/>
          <param name="jndi-name" value="java:jboss/datasources/${env.MARIADB_DATASOURCE:MariaDBDS}"/>
          <param name="connection-url" value="jdbc:mariadb://${env.MARIADB_HOST:localhost}:${env.MARIADB_PORT:3306}/${env.MARIADB_DATABASE}"/> 3
          <param name="driver-name" value="mariadb"/>
          <param name="user-name" value="${env.MARIADB_USER}"/>4
          <param name="password" value="${env.MARIADB_PASSWORD}"/>
   </feature>
   </layer-spec>

   1

   This dependency enforces the provisioning of the MariaDB driver when the datasource is provisioned. All the layers a layer depends on are automatically provisioned when that layer is provisioned.

   2

   Update the datasources subsystem configuration with a datasource named MariaDBDS.

   3

   Datasource’s name, host, port, and database values are resolved from the environment variables MARIADB_DATASOURCE, MARIADB_HOST, MARIADB_PORT, and MARIADB_DATABASE, which are set when the server is started.

   4

   User name and password values are resolved from the environment variables MARIADB_USER and MARIADB_PASSWORD.

9. Build the Galleon feature-pack by running the following command:

   mvn clean install

   The file target/mariadb-galleon-pack-1.0-SNAPSHOT.zip is created.

Procedure

1. Start the MariaDB database by running the following command:

   oc new-app -e MYSQL_USER=admin -e MYSQL_PASSWORD=admin -e MYSQL_DATABASE=mariadb registry.redhat.io/rhscl/mariadb-101-rhel7

   The OpenShift service mariadb-101-rhel7 is created and started.

2. Create a secret from the feature-pack ZIP archive, generated by the custom feature-pack Maven build, by running the following command within the Maven project directory mariadb-galleon-pack:

   oc create secret generic mariadb-galleon-pack --from-file=target/mariadb-galleon-pack-1.0-SNAPSHOT.zip

   The secret mariadb-galleon-pack is created. When initiating the S2I build, this secret is used to mount the feature-pack zip file in the pod, making the file available during the server provisioning phase.

3. To create a new OpenShift build to build an application image containing the todo-backend quickstart deployment running inside a server trimmed with Galleon, run the following command:

   oc new-build jboss-eap74-openjdk11-openshift:latest~https://github.com/jboss-developer/jboss-eap-quickstarts#EAP_7.4.0.GA \
   --context-dir=todo-backend \
   --env=GALLEON_PROVISION_FEATURE_PACKS="org.example.mariadb:mariadb-galleon-pack:1.0-SNAPSHOT" \ 1
   --env=GALLEON_PROVISION_LAYERS="jaxrs-server,mariadb-datasource" \ 2
   --env=GALLEON_CUSTOM_FEATURE_PACKS_MAVEN_REPO="/tmp/repo" \ 3
   --env=MAVEN_ARGS_APPEND="-Dcom.redhat.xpaas.repo.jbossorg" \
   --build-secret=mariadb-galleon-pack:/tmp/repo/org/example/mariadb/mariadb-galleon-pack/1.0-SNAPSHOT \ 4
   --name=todos-app-build

   1

   The custom feature-pack environment variable that contains a comma separated list of feature-pack Maven coordinates, such as groupId:artifactId:version.

   2

   The set of Galleon layers that are used to provision the server. jaxrs-server is a base server layer and mariadb-datasource is the custom layer that brings the MariaDB driver and a new datasource to the server installation.

   3

   The location of the local Maven repository within the image that contains the MariaDB feature-pack. This repository is populated when mounting the secret inside the image.

   4

   The mariadb-galleon-pack secret is mounted in the /tmp/repo/org/example/mariadb/mariadb-galleon-pack/1.0-SNAPSHOT directory.

4. To start a new build from the created OpenShift build, run the following command:

   oc start-build todos-app-build

   After successful command execution, the image todos-app-build is created.

5. To create a new deployment, provide the environment variables that are required to bind the datasource to the running MariaDB database by executing the following command:

   oc new-app --name=todos-app todos-app-build \
   --env=MARIADB_PORT=3306 \
   --env=MARIADB_USER=admin \
   --env=MARIADB_PASSWORD=admin \
   --env=MARIADB_HOST=mariadb-101-rhel7 \
   --env=MARIADB_DATABASE=mariadb  \
   --env=MARIADB_DATASOURCE=ToDos 1

   1

   The quickstart expects the datasource to be named ToDos

   Note

   For more details about the custom Galleon feature-pack environment variables, see Custom Galleon feature-pack environment variables

6. To expose the todos-app application, run the following command:

   oc expose svc/todos-app

7. To create a new task, run the following command:

   curl -X POST http://$(oc get route todos-app --template='{{ .spec.host }}') \
      -H 'Content-Type: application/json' \
      -d '{"title":"todo1"}'

8. To access the list of tasks, run the following command:

   curl http://$(oc get route todos-app --template='{{ .spec.host }}')

   The added task is displayed in a browser.