Spring Boot Microservices

Overview

• The application has been developed using microservice approach.
• We use git monorepo where all microservices are the modules in a single respository.
• Each microservice product-service and review-service can be built and run independently using Java & Gradle.
• Each microservice can build, test, run, dockerize, deploy & run independently using Docker, Jenkins, and Kubernetes

Resources

• Deployment of Spring Boot Microservices using Docker and Jenkins

Product-Service

• You should be able to run product-service at port 8081
• You should be able to access API doc at url http://localhost:8081 after successful application startup

Review-Service

• You should be able to run product-service at port 8082
• You should be able to access API doc at url http://localhost:8082 after successful application startup
• You can perform GET operation without any authentication.
• You need to pass JWT access token in Authorization header in order to perform POST, PUT and DELETE operation.

  Authorization: Bearer jwt_access_token
  

• You should authenticate first using /login api to get the JWT access token. Any username and password will be authenticated successfully for demo purpose.

Common-Library

• Common library has been created for re-usability purpose.
• It provides configuration for API logging, security and documentation.
• It provides exception handler for API
• Common library is used by both product-service and review-service

Dockerize your microservices

It is essential in microservice environment to containerize the build using Docker.

Docker Installation

Docker can be installed on Mac using Brew:-

brew install --cask docker

You should be able to use Docker CLI commands such as docker and docker-compose after installation.

Dockerfile

Added Dockerfile in each microservice to provide configuration to build and run docker image.

1. To build a docker image for product-service, Goto the project's root location, where you have Dockerfile and run following command:-

   $springboot-microservices/product-service > build -t product-service .
   

2. To run product-service application from docker image, run following command:-

   $any_path > docker run -d -p 8081:8081 -e "SPRING_PROFILES_ACTIVE=dev" product-service:latest
   

docker commands are used when you have to build a docker image and run that docker image for an individual microservice. You should use docker-compose commands if you want to build and run docker images for multiple microservices at once.

docker-compose.yaml

Docker compose configuration file docker-compose.yaml is at the root folder of repo directory i.e. springboot-microservices/docker-compose.yaml which provides all the configuration required to build and run docker image of product-service and review-service

Goto the repo root directory springboot-microservices and execute following command to build and run docker images for both the services at port 8081 and 8082 respectively

$springboot-microservices > docker-compose up

You can execute following commands to bring all the services down:-

$springboot-microservices > docker-compose down

Remote Docker Hub

You can create a DockerHub account to push local docker images to remote docker hub repository

1. To login to remote DockerHub account:-

   $any_path > docker login
   

2. To tag local docker image to remote docker image:-

   $any_path > docker tag com.example/product-service:latest aklahoti/product-service/0.0.1
   

3. To push image to remote docker hub repository:-

   $any_path > docker image push aklahoti/product-service:0.0.1 
   

CI/CD pipeline proposal

It is essential to automate the continuous integration and continuous deployment (CI/CD) in microservice environment. For this we have:-

1. Added gradle plugins to build and run docker image using gradle tasks

   plugins {
       id 'com.palantir.docker' version '0.26.0'
       id 'com.palantir.docker-run' version '0.26.0'
   }
   

   You should be able to run :docker and :dockerRun gradle tasks for each microservice after adding the plugins.
2. Added Jenkinsfile in each microservice to build Jenkins pipeline such as build, test, build and push docker image using the Gradle tasks.

Deploy Microservice to Kubernetes (K8S)

Install K8S

K8S can be installed on Mac using Brew:-

brew install kubectl

You should be able to use K8S CLI commands kubectl after installation.

deployment.yml

Added deployment.yml in each microservice to provide configuration for kubernetes load-balancer service, deployment, pod and container.

To deploy docker image of product-service in K8S cluster, Goto the project's root location, where you have application.yml and run following command:-

$springboot-microservices/product-service > kubectl apply -f deployment.yml

This command will create 2 pods for product-service in Kubernetes cluster using RollingUpdate strategy. Load balancer service will be accessible at localhost:9091 which will load balance the traffic to these 2 pods running at port 8081