Vert.x Hibernate Reactive PoC

This PoC project contains a Vert.x Hibernate Reactive setup.

It consists of the following components:

Module	Description
bom	Bill Of Materials POM which tracks all dependency versions.
api	API Module which contains interfaces for the DAO implementation.
io-uring	Vert.x Patches which will enable io uring support in Netty.
flyway	Flyway database migration helper.
hibernate	Hibernate module which contains the reactive DAO implementations
rest	Vert.x REST API implementation
server	Vert.x Http Server runner which provides the REST API

Requirements

• Maven 3.6.3
• JDK 16
• Docker Runtime
• Linux Environment (otherwise io uring can be used)

Core Components

• Vert.x - 4.2.1
• Dagger - 2.39.1
• Hibernate Reactive - 1.1.0.Final
• RxJava - 3.1.3
• Netty - 4.1.69.Final
• Netty io uring - 0.0.10.Final

Building

export JAVA_HOME=<YOUR JDK 16>
mvn clean package -DskipTests

REST API

• POST /users - Adds a new user to the database
• GET /users - Returns UUIDs of all users that have been created
• GET /users/:uuid - Return a specific user
• DELETE /users/:uuid - Delete a specific user

Demo

The server project contains the io.metaloom.poc.Runner class which can be used to start the demo server. Alternatively the server can be started after building via:

java -jar server/target/poc-vertx-hibernate-server-0.0.1-SNAPSHOT.jar

Architecture

1. The Runner class prepares the Dagger 2 dependency graph which is needed for dependency injection.
2. The io.metaloom.poc.dagger.module dagger modules prepare various components for DI that are outside of the project (e.g. Vert.x VertxModule, Hibernate HibernateModule, TestContainer ContainerModule)
3. The Bootstrap class will be used to setup the individual components in the right order (e.g. container->flyway->hibernate->server)
4. The RESTServerImpl class deploys the ServerVerticle verticles which will be provided by dagger.
5. The ServerVerticle verticles startup a HttpServer and register the Vert.x routes for the REST API.
6. The handlers for the routes are located within the GroupCrudHandler and UserCrudHandler classes. The handler code utilizes RxJava3 and the Hibernate DAO implementation to interact with the database.

Docker

The server requires a postgres database. By default this database will be provides using TestContainers during startup of the demo application.

Open Task

• API Testing
• Open API handling
• Authentication?
• Metrics?

Native Image

• Download GraalVM

• Run gu install native-image in the extracted JDK to install native-image support.

• Build the image

export JAVA_HOME=/opt/jvm/graalvm
mvn clean package -DskipTests -Pnative-image