Chapter 4. Developing and deploying Eclipse Vert.x runtime application
In addition to using an example, you can create a new Eclipse Vert.x application and deploy it to OpenShift or stand-alone Red Hat Enterprise Linux.
4.1. Developing Eclipse Vert.x application Copy linkLink copied to clipboard!
For a basic Eclipse Vert.x application, you need to create the following:
- A Java class containing Eclipse Vert.x methods.
-
A
pom.xmlfile containing information required by Maven to build the application.
The following procedure creates a simple Greeting application that returns "Greetings!" as response.
For building and deploying your applications to OpenShift, Eclipse Vert.x 3.9 only supports builder images based on OpenJDK 8 and OpenJDK 11. Oracle JDK and OpenJDK 9 builder images are not supported.
Prerequisites
- OpenJDK 8 or OpenJDK 11 installed.
- Maven installed.
Procedure
Create a new directory
myApp, and navigate to it.$ mkdir myApp $ cd myAppThis is the root directory for the application.
Create directory structure
src/main/java/com/example/in the root directory, and navigate to it.$ mkdir -p src/main/java/com/example/ $ cd src/main/java/com/example/Create a Java class file
MyApp.javacontaining the application code.package com.example; import io.vertx.core.AbstractVerticle; import io.vertx.core.Future; public class MyApp extends AbstractVerticle { @Override public void start(Future<Void> fut) { vertx .createHttpServer() .requestHandler(r -> r.response().end("Greetings!")) .listen(8080, result -> { if (result.succeeded()) { fut.complete(); } else { fut.fail(result.cause()); } }); } }Create a
pom.xmlfile in the application root directorymyAppwith the following content:<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example</groupId> <artifactId>my-app</artifactId> <version>1.0.0-SNAPSHOT</version> <packaging>jar</packaging> <name>My Application</name> <description>Example application using Vert.x</description> <properties> <vertx.version>3.9.6.redhat-00001</vertx.version> <vertx-maven-plugin.version>1.0.23</vertx-maven-plugin.version> <vertx.verticle>com.example.MyApp</vertx.verticle> <!-- Specify the JDK builder image used to build your application. --> <fabric8.generator.from>registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift:latest</fabric8.generator.from> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> </properties> <!-- Import dependencies from the Vert.x BOM. --> <dependencyManagement> <dependencies> <dependency> <groupId>io.vertx</groupId> <artifactId>vertx-dependencies</artifactId> <version>${vertx.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <!-- Specify the Vert.x artifacts that your application depends on. --> <dependencies> <dependency> <groupId>io.vertx</groupId> <artifactId>vertx-core</artifactId> </dependency> <dependency> <groupId>io.vertx</groupId> <artifactId>vertx-web</artifactId> </dependency> </dependencies> <!-- Specify the repositories containing Vert.x artifacts. --> <repositories> <repository> <id>redhat-ga</id> <name>Red Hat GA Repository</name> <url>https://maven.repository.redhat.com/ga/</url> </repository> </repositories> <!-- Specify the repositories containing the plugins used to execute the build of your application. --> <pluginRepositories> <pluginRepository> <id>redhat-ga</id> <name>Red Hat GA Repository</name> <url>https://maven.repository.redhat.com/ga/</url> </pluginRepository> </pluginRepositories> <!-- Configure your application to be packaged using the Vert.x Maven Plugin. --> <build> <plugins> <plugin> <groupId>io.reactiverse</groupId> <artifactId>vertx-maven-plugin</artifactId> <version>${vertx-maven-plugin.version}</version> <executions> <execution> <id>vmp</id> <goals> <goal>initialize</goal> <goal>package</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>Build the application using Maven from the root directory of the application.
$ mvn vertx:runVerify that the application is running.
Using
curlor your browser, verify your application is running athttp://localhost:8080.$ curl http://localhost:8080 Greetings!
Additional information
- As a recommended practice, you can configure liveness and readiness probes to enable health monitoring for your application when running on OpenShift. To learn how application health monitoring on OpenShift works, try the Health Check example.
4.2. Deploying Eclipse Vert.x application to OpenShift Copy linkLink copied to clipboard!
To deploy your Eclipse Vert.x application to OpenShift, configure the pom.xml file in your application and then use the Fabric8 Maven plugin. You can specify a Java image by replacing the fabric8.generator.from URL in the pom.xml file.
The images are available in the Red Hat Ecosystem Catalog.
<fabric8.generator.from>IMAGE_NAME</fabric8.generator.from>
For example, the Java image for RHEL 7 with OpenJDK 8 is specified as:
<fabric8.generator.from>registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift:latest</fabric8.generator.from>
4.2.1. Supported Java images for Eclipse Vert.x Copy linkLink copied to clipboard!
Eclipse Vert.x is certified and tested with various Java images that are available for different operating systems. For example, Java images are available for RHEL 7 and RHEL 8 with OpenJDK 8 or OpenJDK 11. Similar images are available on IBM Z and IBM Power Systems.
You require Docker or podman authentication to access the RHEL 8 images in the Red Hat Ecosystem Catalog.
The following table lists the images supported by Eclipse Vert.x for different architectures. It also provides links to the images available in the Red Hat Ecosystem Catalog. The image pages contain authentication procedures required to access the RHEL 8 images.
4.2.1.1. Images on x86_64 architecture Copy linkLink copied to clipboard!
| OS | Java | Red Hat Ecosystem Catalog |
|---|---|---|
| RHEL 7 | OpenJDK 8 | |
| RHEL 7 | OpenJDK 11 | |
| RHEL 8 | OpenJDK 8 | |
| RHEL 8 | OpenJDK 11 |
The use of a RHEL 8-based container on a RHEL 7 host, for example with OpenShift 3 or OpenShift 4, has limited support. For more information, see the Red Hat Enterprise Linux Container Compatibility Matrix.
4.2.1.2. Images on s390x (IBM Z) architecture Copy linkLink copied to clipboard!
| OS | Java | Red Hat Ecosystem Catalog |
|---|---|---|
| RHEL 8 | Eclipse OpenJ9 11 |
4.2.1.3. Images on ppc64le (IBM Power Systems) architecture Copy linkLink copied to clipboard!
| OS | Java | Red Hat Ecosystem Catalog |
|---|---|---|
| RHEL 8 | Eclipse OpenJ9 11 |
The use of a RHEL 8-based container on a RHEL 7 host, for example with OpenShift 3 or OpenShift 4, has limited support. For more information, see the Red Hat Enterprise Linux Container Compatibility Matrix.
4.2.2. Preparing Eclipse Vert.x application for OpenShift deployment Copy linkLink copied to clipboard!
For deploying your Eclipse Vert.x application to OpenShift, it must contain:
-
Launcher profile information in the application’s
pom.xmlfile. - A deployment yaml file containing environment details.
In the following procedure, a profile with Fabric8 Maven plugin is used for building and deploying the application to OpenShift.
Prerequisites
- Maven is installed.
- Docker or podman authentication into Red Hat Ecosystem Catalog to access RHEL 8 images.
Procedure
Add the following content to the
pom.xmlfile in the application root directory:<!-- Specify the JDK builder image used to build your application. --> <properties> <fabric8.generator.from>registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift:latest</fabric8.generator.from> </properties> ... <profiles> <profile> <id>openshift</id> <build> <plugins> <plugin> <groupId>io.fabric8</groupId> <artifactId>fabric8-maven-plugin</artifactId> <version>4.4.1</version> <executions> <execution> <goals> <goal>resource</goal> <goal>build</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </profile> </profiles>Replace the
fabric8.generator.fromproperty in thepom.xmlfile to specify the OpenJDK image that you want to use.x86_64 architecture
RHEL 7 with OpenJDK 8
<fabric8.generator.from>registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift:latest</fabric8.generator.from>RHEL 7 with OpenJDK 11
<fabric8.generator.from>registry.access.redhat.com/openjdk/openjdk-11-rhel7:latest</fabric8.generator.from>RHEL 8 with OpenJDK 8
<fabric8.generator.from>registry.redhat.io/openjdk/openjdk-8-rhel8:latest</fabric8.generator.from>RHEL 8 with OpenJDK 11
<fabric8.generator.from>registry.redhat.io/openjdk/openjdk-11-rhel8:latest</fabric8.generator.from>
s390x (IBM Z) architecture
RHEL 8 with Eclipse OpenJ9 11
<fabric8.generator.from>registry.access.redhat.com/openj9/openj9-11-rhel8:latest</fabric8.generator.from>
ppc64le (IBM Power Systems) architecture
RHEL 8 with Eclipse OpenJ9 11
<{fabric8}.generator.from>registry.access.redhat.com/openj9/openj9-11-rhel8:latest</{fabric8}.generator.from>
Create
deployment.yamlfile insrc/main/fabric8directory with the following content:spec: template: spec: containers: - name: vertx env: - name: KUBERNETES_NAMESPACE valueFrom: fieldRef: apiVersion: template.openshift.io/v1 fieldPath: metadata.namespace - name: JAVA_OPTIONS value: '-Dvertx.cacheDirBase=/tmp -Dvertx.jgroups.config=default'
4.2.3. Deploying Eclipse Vert.x application to OpenShift using Fabric8 Maven plugin Copy linkLink copied to clipboard!
To deploy your Eclipse Vert.x application to OpenShift, you must perform the following:
- Log in to your OpenShift instance.
- Deploy the application to the OpenShift instance.
Prerequisites
-
ocCLI client installed. - Maven installed.
Procedure
Log in to your OpenShift instance with the
occlient.$ oc login ...Create a new project in the OpenShift instance.
$ oc new-project MY_PROJECT_NAMEDeploy the application to OpenShift using Maven from the application’s root directory. The root directory of an application contains the
pom.xmlfile.$ mvn clean fabric8:deploy -PopenshiftThis command uses the Fabric8 Maven Plugin to launch the S2I process on OpenShift and start the pod.
Verify the deployment.
Check the status of your application and ensure your pod is running.
$ oc get pods -w NAME READY STATUS RESTARTS AGE MY_APP_NAME-1-aaaaa 1/1 Running 0 58s MY_APP_NAME-s2i-1-build 0/1 Completed 0 2mThe
MY_APP_NAME-1-aaaaapod should have a status ofRunningonce it is fully deployed and started.Your specific pod name will vary.
Determine the route for the pod.
Example Route Information
$ oc get routes NAME HOST/PORT PATH SERVICES PORT TERMINATION MY_APP_NAME MY_APP_NAME-MY_PROJECT_NAME.OPENSHIFT_HOSTNAME MY_APP_NAME 8080The route information of a pod gives you the base URL which you use to access it.
In this example,
http://MY_APP_NAME-MY_PROJECT_NAME.OPENSHIFT_HOSTNAMEis the base URL to access the application.Verify that your application is running in OpenShift.
$ curl http://MY_APP_NAME-MY_PROJECT_NAME.OPENSHIFT_HOSTNAME Greetings!
4.3. Deploying Eclipse Vert.x application to stand-alone Red Hat Enterprise Linux Copy linkLink copied to clipboard!
To deploy your Eclipse Vert.x application to stand-alone Red Hat Enterprise Linux, configure the pom.xml file in the application, package it using Maven and deploy using the java -jar command.
Prerequisites
- RHEL 7 or RHEL 8 installed.
4.3.1. Preparing Eclipse Vert.x application for stand-alone Red Hat Enterprise Linux deployment Copy linkLink copied to clipboard!
For deploying your Eclipse Vert.x application to stand-alone Red Hat Enterprise Linux, you must first package the application using Maven.
Prerequisites
- Maven installed.
Procedure
Add the following content to the
pom.xmlfile in the application’s root directory:... <build> <plugins> <plugin> <groupId>io.reactiverse</groupId> <artifactId>vertx-maven-plugin</artifactId> <version>${vertx-maven-plugin.version}</version> <executions> <execution> <id>vmp</id> <goals> <goal>initialize</goal> <goal>package</goal> </goals> </execution> </executions> </plugin> </plugins> </build> ...Package your application using Maven.
$ mvn clean packageThe resulting JAR file is in the
targetdirectory.
4.3.2. Deploying Eclipse Vert.x application to stand-alone Red Hat Enterprise Linux using jar Copy linkLink copied to clipboard!
To deploy your Eclipse Vert.x application to stand-alone Red Hat Enterprise Linux, use java -jar command.
Prerequisites
- RHEL 7 or RHEL 8 installed.
- OpenJDK 8 or OpenJDK 11 installed.
- A JAR file with the application.
Procedure
Deploy the JAR file with the application.
$ java -jar my-app-fat.jarVerify the deployment.
Use
curlor your browser to verify your application is running athttp://localhost:8080:$ curl http://localhost:8080