rest-villains

Superheroes Villain Microservice

Table of Contents

• Introduction
  • Exposed Endpoints
• Contract testing with Pact
• Running the Application
• Running Locally via Docker Compose
• Deploying to Kubernetes
  • Using pre-built images
  • Deploying directly via Kubernetes Extensions

Introduction

This is the Villain REST API microservice. It is a classical HTTP microservice exposing CRUD operations on Villains. Villain information is stored in a PostgreSQL database. This service is implemented using RESTEasy Reactive with blocking endpoints and Quarkus Hibernate ORM with Panache's active record pattern.

Additionally, this application favors field injection of beans (i.e. @Inject annotation) over constructor injection.

Exposed Endpoints

The following table lists the available REST endpoints. The OpenAPI document for the REST endpoints is also available.

Path	HTTP method	Query Param(s)	Response Status	Response Object	Description
/api/villains	GET	name_filter	200	List<Villain>	All Villains. Empty array ([]) if none. Optional name_filter query parameter for filtering results by name (case-insensitive).
/api/villains	POST		201		New Villain created. Location header contains URL to retrieve Villain
/api/villains	POST		400		Invalid Villain passed in request body (or no request body found)
/api/villains	DELETE		204		Deletes all Villains
/api/villains	PUT		201		Replaces all villains with the passed-in villains. Location header contains URL to retrieve all Villains
/api/villains	PUT		400		Invalid Villains passed in request body (or no request body found)
/api/villains/random	GET		200	Villain	Random Villain
/api/villains/random	GET		404		No Villain found
/api/villains/{id}	GET		200	Villain	Villain with id == {id}
/api/villains/{id}	GET		404		No Villain with id == {id} found
/api/villains/{id}	PUT		204		Completely replaces a Villain
/api/villains/{id}	PUT		400		Invalid Villain passed in request body (or no request body found)
/api/villains/{id}	PUT		404		No Villain with id == {id} found
/api/villains/{id}	PATCH		200	Villain	Partially updates a Villain. Returns the complete Villain.
/api/villains/{id}	PATCH		400		Invalid Villain passed in request body (or no request body found)
/api/villains/{id}	PATCH		404		No Villain with id == {id} found
/api/villains/{id}	DELETE		204		Deletes Villain with id == {id}
/api/villains/hello	GET		200	String	Ping "hello" endpoint

Contract testing with Pact

Pact is a code-first tool for testing HTTP and message integrations using contract tests. Contract tests assert that inter-application messages conform to a shared understanding that is documented in a contract. Without contract testing, the only way to ensure that applications will work correctly together is by using expensive and brittle integration tests.

Eric Deandrea and Holly Cummins recently spoke about contract testing with Pact and used the Quarkus Superheroes for their demos. Watch the replay and view the slides if you'd like to learn more about contract testing.

The rest-villains application is a Pact Provider, and as such, should run provider verification tests against contracts produced by consumers.

As this README states, contracts generally should be hosted in a Pact Broker and then automatically discovered in the provider verification tests.

Therefore, the Pact contract is committed into this application's source tree inside the src/test/resources/pacts directory. In a realistic scenario, if a broker wasn't used, the consumer's CI/CD would commit the contracts into this repository's source control.

The Pact tests use the Quarkus Pact extension. This extension is recommended to give the best user experience and ensure compatibility.

Running the Application

The application runs on port 8084 (defined by quarkus.http.port in application.properties).

From the quarkus-super-heroes/rest-villains directory, simply run ./mvnw quarkus:dev to run Quarkus Dev Mode, or running quarkus dev using the Quarkus CLI. The application will be exposed at http://localhost:8084 and the Quarkus Dev UI will be exposed at http://localhost:8084/q/dev.

The application also contains a simple UI, showing the list of Villains currently stored. This UI is available at the root path (http://localhost:8084). The UI is built using the Quarkus Qute templating engine.

NOTE: Running the application outside of Quarkus dev mode requires standing up a PostgreSQL instance and binding it to the app. By default, the application is configured with the following:

Description	Environment Variable	Java Property	Value
Database URL	QUARKUS_DATASOURCE_JDBC_URL	quarkus.datasource.jdbc.url	jdbc:postgresql://localhost:5432/villains_database
Database username	QUARKUS_DATASOURCE_USERNAME	quarkus.datasource.username	superbad
Database password	QUARKUS_DATASOURCE_PASSWORD	quarkus.datasource.password	superbad

Running Locally via Docker Compose

Pre-built images for this application can be found at quay.io/quarkus-super-heroes/rest-villains.

Pick one of the 4 versions of the application from the table below and execute the appropriate docker compose command from the quarkus-super-heroes/rest-villains directory.

NOTE: You may see errors as the applications start up. This may happen if an application completes startup before one if its required services (i.e. database, kafka, etc). This is fine. Once everything completes startup things will work fine.

Description	Image Tag	Docker Compose Run Command
JVM Java 17	java17-latest-rhbq-3.2	docker compose -f deploy/docker-compose/java17.yml up --remove-orphans
Native	native-latest-rhbq-3.2	docker compose -f deploy/docker-compose/native.yml up --remove-orphans

These Docker Compose files are meant for standing up this application and the required database only. If you want to stand up the entire system, follow these instructions.

Once started the application will be exposed at http://localhost:8084.

Deploying to Kubernetes

The application can be deployed to Kubernetes using pre-built images or by deploying directly via the Quarkus Kubernetes Extension. Each of these is discussed below.

Using pre-built images

Pre-built images for this application can be found at quay.io/quarkus-super-heroes/rest-villains.

Deployment descriptors for these images are provided in the deploy/k8s directory. There are versions for OpenShift, Minikube, Kubernetes, and KNative.

Pick one of the 4 versions of the application from the table below and deploy the appropriate descriptor from the deploy/k8s directory.

Description	Image Tag	OpenShift Descriptor	Minikube Descriptor	Kubernetes Descriptor	KNative Descriptor
JVM Java 17	java17-latest-rhbq-3.2	java17-openshift.yml	java17-minikube.yml	java17-kubernetes.yml	java17-knative.yml
Native	native-latest-rhbq-3.2	native-openshift.yml	native-minikube.yml	native-kubernetes.yml	native-knative.yml

The application is exposed outside of the cluster on port 80.

These are only the descriptors for this application and the required database only. If you want to deploy the entire system, follow these instructions.

Deploying directly via Kubernetes Extensions

Following the deployment section of the Quarkus Kubernetes Extension Guide (or the deployment section of the Quarkus OpenShift Extension Guide if deploying to OpenShift), you can run one of the following commands to deploy the application and any of its dependencies (see Kubernetes (and variants) resource generation of the automation strategy document) to your preferred Kubernetes distribution.

NOTE: For non-OpenShift or minikube Kubernetes variants, you will most likely need to push the image to a container registry by adding the -Dquarkus.container-image.push=true flag, as well as setting the quarkus.container-image.registry, quarkus.container-image.group, and/or the quarkus.container-image.name properties to different values.

Target Platform	Java Version	Command
Kubernetes	17	./mvnw clean package -Dquarkus.profile=kubernetes -Dquarkus.kubernetes.deploy=true -DskipTests
OpenShift	17	./mvnw clean package -Dquarkus.profile=openshift -Dquarkus.container-image.registry=image-registry.openshift-image-registry.svc:5000 -Dquarkus.container-image.group=$(oc project -q) -Dquarkus.kubernetes.deploy=true -DskipTests
Minikube	17	./mvnw clean package -Dquarkus.profile=minikube -Dquarkus.kubernetes.deploy=true -DskipTests
KNative	17	./mvnw clean package -Dquarkus.profile=knative -Dquarkus.kubernetes.deploy=true -DskipTests
KNative (on OpenShift)	17	./mvnw clean package -Dquarkus.profile=knative-openshift -Dquarkus.container-image.registry=image-registry.openshift-image-registry.svc:5000 -Dquarkus.container-image.group=$(oc project -q) -Dquarkus.kubernetes.deploy=true -DskipTests

You may need to adjust other configuration options as well (see Quarkus Kubernetes Extension configuration options and Quarkus OpenShift Extension configuration options).

The do_build function in the generate-k8s-resources.sh script uses these extensions to generate the manifests in the deploy/k8s directory.