Spring Boot 3 Microservices

This repository contains the latest source code of the spring-boot-microservices tutorial

You can watch the tutorial on Youtube here

Modules

api-gateway：This service is an API Gateway to the internal backend services
- TechStack: Spring Boot, Spring Cloud Gateway, Spring Cloud CircuitBreaker, Resilience4J, SpringDoc, Prometheus, Zipkin, Loki
inventory-service：This services provides REST API for managing inventory.
- TechStack: Spring Boot, Spring Data JPA, MySQL, SpringDoc, Prometheus, Zipkin, Loki
notification-service：This services provides REST API for sending notifications.
- TechStack: Spring Boot, Spring Kafka, Avro, Mail, SpringDoc, Prometheus, Zipkin, Loki
order-service：This services provides REST API for managing orders.
- TechStack: Spring Boot, Spring Data JPA, MySQL, Spring Kafka, Avro, Spring Cloud CircuitBreaker, Resilience4J, Spring WebFlux, SpringDoc, Prometheus, Zipkin, Loki
product-service：This services provides REST API for managing products and catalogs.
- TechStack: Spring Boot, Spring Data JPA, Mongodb, SpringDoc, Prometheus, Zipkin, Loki

Tech Stack

Building Spring Boot REST APIs
Creating Aggregated Swagger Documentation at API Gateway
Database Persistence using Spring Data JPA, MySQL, Mongodb, Flyway
Distributed Tracing using Zipkin
Distributed Logging using Loki
Event Driven Async Communication using Spring Kafka and avro
Implementing API Gateway using Spring Cloud Gateway
Implementing Resiliency using Resilience4j
Using WebClient, Declarative HTTP Interfaces to invoke other APIs
Local Development Setup using Docker, Docker Compose and Testcontainers
Monitoring & Observability using Grafana, Prometheus, Tempo
Testing using JUnit 5, RestAssured, Testcontainers, Awaitility, WireMock
Deployment to Kubernetes using Kind

Application Architecture

Local Development Setup

Install Java 21 and Maven 3. Recommend using SDKMAN.
Install Docker. Recommend using OrbStack for Macos.
Install IntelliJ IDEA or any of your favorite IDE
Install Postman or any REST Client

How to build the backend services

Run the following command to build and package the backend services into a docker container

mvn spring-boot:build-image -DskipTests

If you want to push the docker images to your docker hub account, you can use the following command.

mvn spring-boot:build-image -DskipTests \
  -Ddocker.publishRegistry.username=user \
  -Ddocker.publishRegistry.password=secret \
  -Dspring-boot.build-image.publish=true

The above command will build and package the services into a docker container and push it to your docker hub account.

How to run the services

Make sure you have the following installed on your machine:

Java 21
Docker
Kind Cluster - https://kind.sigs.k8s.io/docs/user/quick-start/#installation

Start Kind Cluster

Run the k8s/kind/create-cluster.sh script to create the kind Kubernetes cluster

./k8s/kind/create-cluster.sh

This will create a kind cluster and pre-load all the required docker images into the cluster, this will save you time downloading the images when you deploy the application.

Deploy the infrastructure

Run the k8s/manisfests/infrastructure.yaml file to deploy the infrastructure

kubectl apply -f k8s/manifests/infrastructure

Deploy the services

Run the k8s/manifests/applications.yaml file to deploy the services

kubectl apply -f k8s/manifests/applications

Access the API Gateway

To access the API Gateway, you need to port-forward the gateway service to your local machine

kubectl port-forward svc/api-gateway 9000:9000

Access the Grafana Dashboards

To access the Grafana dashboards, you need to port-forward the grafana service to your local machine

kubectl port-forward svc/grafana 3000:3000

Delete Kind Cluster