Chapter 3. Developing and deploying Eclipse Vert.x runtime application
You can create a new Eclipse Vert.x application and deploy it to OpenShift or stand-alone Red Hat Enterprise Linux.
3.1. 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 4.2 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.Promise; public class MyApp extends AbstractVerticle { @Override public void start(Promise<Void> promise) { vertx .createHttpServer() .requestHandler(r -> r.response().end("Greetings!")) .listen(8080, result -> { if (result.succeeded()) { promise.complete(); } else { promise.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>4.2.7.redhat-00003</vertx.version> <vertx-maven-plugin.version>1.0.24</vertx-maven-plugin.version> <vertx.verticle>com.example.MyApp</vertx.verticle> <!-- Specify the JDK builder image used to build your application. --> <jkube.generator.from>registry.access.redhat.com/ubi8/openjdk-11</jkube.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.
3.2. 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 OpenShift Maven plugin.
The Fabric8 Maven plugin is no longer supported. Use the OpenShift Maven plugin to deploy your Eclipse Vert.x applications on OpenShift. For more information, see the section migrating from Fabric8 Maven Plugin to Eclipse JKube.
You can specify a Java image by replacing the jkube.generator.from URL in the pom.xml file. The images are available in the Red Hat Ecosystem Catalog.
<jkube.generator.from>IMAGE_NAME</jkube.generator.from>
For example, the Java image for RHEL 7 with OpenJDK 8 is specified as:
<jkube.generator.from>registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift:latest</jkube.generator.from>
3.2.1. 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 with OpenJDK 8 or OpenJDK 11.
Eclipse Vert.x introduces support for building and deploying Eclipse Vert.x applications to OpenShift with OCI-compliant Universal Base Images for Red Hat OpenJDK 8 and Red Hat OpenJDK 11 on RHEL 8.
You require Docker or podman authentication to access the RHEL 8 images in the Red Hat Ecosystem Catalog.
The following table lists the container images supported by Eclipse Vert.x for different architectures. These container images are available in the Red Hat Ecosystem Catalog. In the catalog, you can search and download the images listed in the table below. The image pages contain authentication procedures required to access the images.
| JDK (OS) | Architecture supported | Images available in Red Hat Ecosystem Catalog |
|---|---|---|
| OpenJDK8 (RHEL 7) | x86_64 | redhat-openjdk-18/openjdk18-openshift |
| OpenJDK11 (RHEL 7) | x86_64 | openjdk/openjdk-11-rhel7 |
| OpenJDK8 (RHEL 8) | x86_64 | ubi8/openjdk-8-runtime |
| OpenJDK11 (RHEL 8) | x86_64, IBM Z, and IBM Power Systems | ubi8/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.
3.2.2. 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.
In the following procedure, a profile with OpenShift 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> <jkube.generator.from>registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift:latest</jkube.generator.from> </properties> ... <profiles> <profile> <id>openshift</id> <build> <plugins> <plugin> <groupId>org.eclipse.jkube</groupId> <artifactId>openshift-maven-plugin</artifactId> <version>1.1.1</version> <executions> <execution> <goals> <goal>resource</goal> <goal>build</goal> <goal>apply</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </profile> </profiles>Replace the
jkube.generator.fromproperty in thepom.xmlfile to specify the OpenJDK image that you want to use.x86_64 architecture
RHEL 7 with OpenJDK 8
<jkube.generator.from>registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift:latest</jkube.generator.from>RHEL 7 with OpenJDK 11
<jkube.generator.from>registry.access.redhat.com/openjdk/openjdk-11-rhel7:latest</jkube.generator.from>RHEL 8 with OpenJDK 8
<jkube.generator.from>registry.access.redhat.com/ubi8/openjdk-8:latest</jkube.generator.from>
x86_64, s390x (IBM Z), and ppc64le (IBM Power Systems) architectures
RHEL 8 with OpenJDK 11
<jkube.generator.from>registry.access.redhat.com/ubi8/openjdk-11:latest</jkube.generator.from>
3.2.3. Deploying Eclipse Vert.x application to OpenShift using OpenShift 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 oc:deploy -PopenshiftThis command uses the OpenShift 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!
3.3. 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.
3.3.1. 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>1.0.24</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.
3.3.2. 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