This repository contains examples of how to build a Java microservices architecture with Spring Boot, Spring Cloud, and Netflix Eureka.

This repository has four examples in it:

1. The first is a bare-bones microservices architecture with Spring Boot, Spring Cloud, Eureka Server, and Zuul.
2. The second is one that's built with JHipster and configured centrally with Spring Cloud Config.
3. The third uses Spring Cloud Gateway and Spring WebFlux to show reactive microservices.
4. The fourth uses JHipster 7 to generate a reactive microservices architecture with Spring Cloud Gateway and Spring WebFlux.

We think you'll enjoy them all!

• See Java Microservices with Spring Boot and Spring Cloud for an overview of the first example.
• Read Java Microservices with Spring Cloud Config and JHipster to learn about microservices with JHipster.
• Refer to Secure Reactive Microservices with Spring Cloud Gateway to learn about Spring Cloud Gateway and reactive microservices.
• Refer to Reactive Java Microservices with Spring Boot and JHipster to see how JHipster makes reactive microservices a breeze.

Prerequisites: Java 11 and an internet connection.

• Spring Boot + Spring Cloud Example
• JHipster + Spring Cloud Config Example
• Spring Cloud Gateway Example
• Reactive Microservices with JHipster Example
• Links
• Help
• License

To install this example, run the following commands:

git clone https://github.com/oktadeveloper/java-microservices-examples.git
cd java-microservices-examples/spring-boot+cloud

The api-gateway and car-service projects are already pre-configured to be locked down with OAuth 2.0 and Okta. That means if you try to run them, you won't be able to login until you create an account, and an application in it.

Log in to your Okta Developer account (or sign up if you don't have an account).

1. From the Applications page, choose Add Application.
2. On the Create New Application page, select Web.
3. Give your app a memorable name, add http://localhost:8080/login/oauth2/code/okta as a Login redirect URI, select Refresh Token (in addition to Authorization Code), and click Done.

Copy the issuer (found under API > Authorization Servers), client ID, and client secret into the application.properties of the api-gateway and car-service projects.

okta.oauth2.issuer=https://{yourOktaDomain}/oauth2/default
okta.oauth2.client-id=$clientId
okta.oauth2.client-secret=$clientSecret

Then, run all the projects with ./mvnw in separate terminal windows. You should be able to navigate to http://localhost:8761 and see the apps have been registered with Eureka.

Then, navigate to http://localhost:8080/cool-cars in your browser, log in with Okta, and see the resulting JSON.

To install this example, run the following commands:

git clone https://github.com/oktadeveloper/java-microservices-examples.git
cd java-microservices-examples/jhipster

Create Docker containers for all gateway and microservice applications:

mvn -Pprod verify com.google.cloud.tools:jib-maven-plugin:dockerBuild

Log in to your Okta Developer account (or sign up if you don't have an account).

1. From the Applications page, choose Add Application.
2. On the Create New Application page, select Web.
3. Give your app a memorable name, add http://localhost:8080/login/oauth2/code/okta as a Login redirect URI, select Refresh Token (in addition to Authorization Code), and click Done.
4. To configure Logout to work in JHipster, Edit your app, add http://localhost:8080 as a Logout redirect URI, then click Save.

Rather than modifying each of your apps for Okta, you can use Spring Cloud Config in JHipster Registry to do it. Open docker-compose/central-server-config/application.yml and add your Okta settings.

The client ID and secret are available on your app settings page. You can find the issuer under API > Authorization Servers.

spring:
  security:
    oauth2:
      client:
        provider:
          oidc:
            issuer-uri: https://{yourOktaDomain}/oauth2/default
        registration:
          oidc:
            client-id: {yourClientId}
            client-secret: {yourClientSecret}

The registry, gateway, blog, and store applications are all configured to read this configuration on startup.

Start all your containers from the docker-compose directory:

docker-compose up -d

Before you can log in to the registry, you'll need to add redirect URIs for JHipster Registry, ensure your user is in a ROLE_ADMIN group and that groups are included in the ID token.

Log in to your Okta dashboard, edit your OIDC app, and add the following Login redirect URI:

• http://localhost:8761/login/oauth2/code/oidc

You'll also need to add a Logout redirect URI:

• http://localhost:8761

Then, click Save.

JHipster is configured by default to work with two types of users: administrators and users. Keycloak is configured with users and groups automatically, but you need to do some one-time configuration for your Okta organization.

Create a ROLE_ADMIN group (Users > Groups > Add Group) and add your user to it. Navigate to API > Authorization Servers, and click on the the default server. Click the Claims tab and Add Claim. Name it groups, and include it in the ID Token. Set the value type to Groups and set the filter to be a Regex of .*. Click Create.

Now when you hit http://localhost:8761 or http://localhost:8080, you should be able to log in with Okta!

To install this example, run the following commands:

git clone https://github.com/oktadeveloper/java-microservices-examples.git
cd java-microservices-examples/spring-cloud-gateway

The api-gateway and car-service projects are already pre-configured to be locked down with OAuth 2.0 and Okta. That means if you try to run them, you won't be able to login until you create an account, and an application in it.

If you already have an Okta account, see the Create a Web Application in Okta section below. Otherwise, we created a Maven plugin that configures a free Okta developer account + an OIDC app (in under a minute!).

To use it, run ./mvnw com.okta:okta-maven-plugin:setup to create an account and configure the gateway to work with Okta.

Copy the okta.* properties from the gateway's src/main/resources/application.properties to the same file in the car-service project.

Then, run all the projects with ./mvnw in separate terminal windows. You should be able to navigate to http://localhost:8761 and see the apps have been registered with Eureka.

Then, navigate to http://localhost:8080/cars in your browser, log in with Okta, and see the resulting JSON.

Log in to your Okta Developer account (or sign up if you don't have an account).

1. From the Applications page, choose Add Application.
2. On the Create New Application page, select Web.
3. Give your app a memorable name, add http://localhost:8080/login/oauth2/code/okta as a Login redirect URI and click Done.

Copy the issuer (found under API > Authorization Servers), client ID, and client secret into the application.properties of the api-gateway and car-service projects.

okta.oauth2.issuer=https://{yourOktaDomain}/oauth2/default
okta.oauth2.client-id=$clientId
okta.oauth2.client-secret=$clientSecret

To install this example, run the following commands:

git clone https://github.com/oktadeveloper/java-microservices-examples.git
cd java-microservices-examples/reactive-jhipster

The JHipster Registry and Spring Cloud Config are pre-configured to use Okta. That means if you try to run them, you won't be able to login until you create an account, and an application in it.

Install the Okta CLI using the instructions on cli.okta.com and come back here when you're done. If you don't have an Okta developer account, run okta register.

NOTE: You can also use your browser and Okta's developer console to register an app. See JHipster's security documentation for those instructions.

From the gateway project's directory, run okta apps create jhipster. Accept the default redirect URIs.

This process does several things:

1. Registers an OIDC app in Okta with JHipster's configured redirect URIs.
2. Creates ROLE_ADMIN and ROLE_USER groups and adds your user to both.
3. Creates a groups claim and adds it to ID tokens.
4. Creates a .okta.env file with the values you'll need to talk to Okta.

Spring Cloud Config allows you to distribute Spring's configuration between apps. Update gateway/src/main/docker/central-server-config/localhost-config/application.yml to use your Okta app settings. You can find the values for each property in the .okta.env file.

spring:
  security:
    oauth2:
      client:
        provider:
          oidc:
            issuer-uri: https://<your-okta-domain>/oauth2/default
        registration:
          oidc:
            client-id: <client-id>
            client-secret: <client-secret>

Save your changes. These values will be distributed to the JHipster Registry, gateway, blog, and store apps. Start all the services and apps using the following commands:

cd gateway
docker-compose -f src/main/docker/keycloak.yml up -d #jhkeycloakup
docker-compose -f src/main/docker/postgresql.yml up -d #jhpostgresqlup
docker-compose -f src/main/docker/jhipster-registery up -d #jhregistryup
./gradlew

Open a new terminal window, start the blog app's Neo4j database, and then the app itself.

cd ../blog
docker-compose -f src/main/docker/neo4j.yml up -d #jhneo4jup
./gradlew

Then, open another terminal window, start the store app's MongoDB database, and the microservice.

cd ../store
docker-compose -f src/main/docker/mongodb.yml up -d #jhmongoup
./gradlew

Now, open a new incognito browser window, go to http://localhost:8080, and sign in. Rejoice that using Okta for authentication works!

TIP: You can also run everything using Docker Compose. See the blog post for how to do that.

These examples uses the following open source libraries:

• Okta Spring Boot Starter
• Spring Boot
• Spring Cloud
• Spring Cloud Gateway
• Spring Security
• JHipster
• OpenJDK

Please post any questions as comments on the example's blog post, or on the Okta Developer Forums.

Apache 2.0, see LICENSE.