MicroProfile tutorial

What is this tutorial about

This tutorial will allow you to explore the full potential of MicroProfile through a step by step development of a small Microservice based JavaEE web application.

What is a MicroProfile?

MicroProfile is an initiative which attempts to bring together experts from the vendors, organizations like JUGs and individuals, make them agree in the open on how should a certain microservice pattern be implemented and put that in an open specification with an open TCK.

It started June 2016 four vendors (RedHat, IBM, Tomitribe and Payara) and an organization (London Java Community) announced version 1 of MicroProfile. It defined a minimal MicroProfile runtime consisting of three Java EE standards:

• JAX-RS

• CDI

• JSON-P

with the intent of community having an active role in the MicroProfile definition and roadmap.

The MicroProfile releases were scheduled twice a year. They followed the release train approach: whichever spec was ready by the final date, was considered to be in. The picture so far is the following:

• MicroProfile 1.1

  • Config 1.0

• MicroProfile 1.2

  • Config 1.1

  • Health Check 1.0

  • Metrics 1.0

  • Fault Tolerance 1.0

  • JWT Propagation 1.0

• MicroProfile 1.3

  • Open Tracing 1.0

  • OpenAPI 1.0

  • REST Client 1.0

This hands-on-lab will focus on the specs introduced up to MicroProfile 1.2.

What will we do?

In order to showcase the various MicroProfile specification, we will enhance a simple sample microservice application. It is used by owners of a magazine to manage the various parts of their business. The app consists of five microservices, each of which can be scaled and upgraded separately. Not only that, but the microservices run on different MicroProfile runtimes.

Here is a brief description of the features:

• The users microservice (implemented on WildFly Swarm) knows about all the users along with their roles in the system. A user can be subscriber, author or manager, or may not have role. If you want to log in or register users, you go to that microservice

• The content microservice (implemented on IBM Open Liberty) keeps track of all the articles published in the magazine

• The authors microservice (implemented on Hammock) provides additional information about users in the author role

• The subscribers microservice (implemented on Payara Micro) has the same task, but for users in the subscriber role

• Finally, the gui microservice (implemented on Apache TomEE) provides a web site that integrates the above microservices

Initially, the five microservices are implemented with MicroProfile 1.0. Which means that they use CDI, JAX-RS and JSON-P to fulfill their requirements. In the following step by step guide we will show you how you can use the various MicroProfile specs with this application.

Let’s start

Download the lab archive and extract it. You will notice inside a PDF and a directory with a maven multi-module project.

The PDF is the lab handout. Open it and follow the instructions.

The sources folder is the showcase project. Each microservice is represented as a separate Maven module. We encourage you to import it in your IDE.

There are also helper scripts to start the separate services as well as one that starts them all. Usually you will only need a subset of them to be running, so you may only use the individual service scripts. When you update the service code, just kill the process of its microservice and run it again.

Let’s get the microservice party started!