MicroProfile Samples

The purpose of this Github repository is to showcase typical use cases of MicroProfile APIs in applications development.

Pre Requisites

Project Structure

The project is a backend for a book store. It provides a REST API to Create, Read, Update and Delete books, and a REST API to retrieve the ISBN of the book.

number-api - A service to generate configurable Numbers.
book-api - A service to manage books.
standalone - A standalone client to call the Book API.
simulator - A client simulator that generates random requests to the Book API and simulate traffic.

MicroProfile APIs

The following MicroProfile APIs can be found through the project:

Config (to generate the prefix of the Number API generation)
OpenAPI (to document the REST API of both Number API and Book API)
JWT (to authenticate and authorize calls that manage books)
Fault Tolerance (to handle ISBN book generation if Number API cannot be called)
Open Tracing (to trace calls between Book API and Number API)
Reactive Messaging (to store Books that require ISBN book generation due to failure)
Metrics (to record call statistics and count how many books require ISBN)
Health (to monitor health of the Number API)
REST Client (to call Book API with a standalone client)

Libraries and Infra

The project uses Quarkus as the Java stack, and the built in SmallRye components as the MicroProfile implementations.

The required infrastructure provided by either Docker or Kubernetes includes:

Postgres Database
Kafka
Jaeger
Prometheus

Build

Set up a local Docker Registry first to store the generated Docker images:

docker run -d -p 5000:5000 --restart=always --name docker-registry registry:2

Use Maven to build the project with the following command from the project root:

mvn verify -Dquarkus.container-image.build=true

Run

With Docker

The easiest way to run the entire system is to use docker-compose. This will run the apps, plus all the required infrastructure. Run the following command from the project root:

docker-compose up

Use the following command to stop and remove all the containers:

docker-compose down

With Java

The infrastructure is still required to run the applications properly. They can also be set up manually in the running host, or use docker-compose to start only the required infrastructure:

docker-compose up database zookeeper kafka prometheus jaeger

To execute number-api and book-api directly, run the following command from each module root:

java -jar target/number-api-runner.jar

java -jar target/book-api-runner.jar

With Kubernetes

The infrastructure to run in Kubernetes is available in the .kubernetes folder. To start the infrastructure run:

kubectl apply -f .kubernetes

Quarkus is able to generate the Kubernetes deployment files and deploy the application directly. This requires a Maven build to generate the deployment descriptors:

mvn verify -Dquarkus.container-image.build=true -Dquarkus.kubernetes.deploy=true

Test the Applications

Use Swagger-UI to access the applications REST endpoint and invoke the APIs:

For Authentication and Authorization in book-api you need to call Authorize in the Swagger interface to generate a JWT. Any client_id, and client_secret is acceptable.

To check Metris and Tracing information:

Native Images

Install GraalVM Native Image binary with:

gu install native-image

Set up an environment variable GRAALVM_HOME pointing to the GraalVM installation folder.

mvn package -Pnative

This is going to generate a binary executable for each module. To execute number-api and book-api as native, run the following command from each module root:

./target/number-api-runner

./target/book-apo-runner

Build Native Docker Images

To build Docker Images with the native binaries run the following command:

mvn verify -Pnative -Dquarkus.native.container-build=true -Dquarkus.container-image.build=true

Or to deploy it directly to Kubernetes:

mvn verify -Pnative -Dquarkus.native.container-build=true -Dquarkus.container-image.build=true -Dquarkus.kubernetes.deploy=true

jlmc/microprofile-samples