A hands-on project on microservice Architecture with Java, Spring, and Docker

In this project, I've learned microservice best practices with the latest technologies.

Topics Covered

• Spring Boot
• Spring Cloud (Config, Gateway, Netflix)
• The 12-factor App
• Docker and DockerHub
• Resilience4j
• Zipkin
• Micrometer
• Prometheus
• Grafana
• Apache Kafka

Account Service

• Connected with MySQL server running as a container
• Used FeignClient to invoke other microservices (card service and loan service)
• Connected with config server to get all configurations for all environments
• Implemented Netflix Eureka Client for service registration with the Eureka server
• Distributed tracing and log aggregation
• Monitored microservices metrics & health using Prometheus and Grafana
• Integrated Apache Kafka to save account info

Card Service

Kind of the same implementation as the accounts service

Loan Service

Kind of the same implementation as the accounts service

Config Server

• Load all configuration from a GitHub repository
• Served properties based on the environment
• RefreshScope for configuration changes with spring cloud bus(rabbitmq)
• Encrypt or Decrypt properties in config server

Eureka Server

• Treated as service discovery where other microservices will be registered with it
• Other microservices can locate each by using Eureka Server
• Microservices/clients will send their heartbeats at regular intervals to the central server about their health

Gateway Server

• Known as API gateway implemented using spring cloud gateway
• Handled custom routing requirements from a central place

About Kafka Integration

For simplicity, I've used Kafka producer & consumer in account-service. Created a rest endpoint to save account info in the database. The Kafka producer writes an event into a topic when a client hit the endpoint, and the Kafka consumer consumes the event and writes data into the database.

Docker Compose

• Maintained docker-compose file for dev and prod environment
• Run all related services in a sequential manner using a single command

Some Maven Commands I've Used

Maven Command	Description
"mvn clean install -Dmaven.test.skip=true"	To generate a jar inside target folder without executing any tests.
"mvn spring-boot:run"	To start a springboot maven project
"mvn spring-boot:build-image -Dmaven.test.skip=true"	To generate a docker image using Buildpacks. No need of Dockerfile

Some Docker Commands I've Used

Docker Command	Description
"docker build . -t codelabs/accounts"	To generate a docker image based on a Dockerfile
"docker run -p 8081:8080 codelabs/accounts"	To start a docker container based on a given image
"docker images"	To list all the docker images present in the Docker server
"docker image rm image-id"	To remove one or more images for a given image ids
"docker ps"	To show all running containers
"docker ps -a"	To show all containers including running and stopped
"docker container start container-id"	To start one or more stopped containers
"docker container stop container-id"	To stop one or more running containers
"docker container rm container-id"	To remove one or more containers based on container ids
"docker compose up"	To create and start containers based on given docker compose file
"docker compose stop"	To stop services