voucher-data

A demo system for purchasing voucher data via sms. microservices patterns applied.

Component diagram

Entity diagram

Some explanation for the project

Applying microservices patterns, using Spring Cloud stack

Interprocess communication

Remote procedure invocation

A client invokes a service using a synchronous, remote procedure invocation-based protocol, such as REST (http://microservices.io/patterns/communication-style/messaging.html).

Messaging

A client invokes a service using asynchronous messaging. See http://microservices.io/patterns/communication-style/messaging.html.

Self registration pattern

A service instance registers itself with the service registry. See http://microservices.io/patterns/self-registration.html.

Client-side discovery

A service client retrieves the list of available service instances from the service reg- istry and load balances across them. See http://microservices.io/patterns/client-side-discovery.html.

Timeout pattern

Never block indefinitely and always use timeouts when waiting for a response. Using timeouts ensures that resources are never tied up indefinitely.

This is used in voucher-service, when it makes sync call to the third party for voucher code. After timeout reaches, voucher-service returns to client a message: "the request is being processed within 30 seconds".

OOP design pattern

Method factory

Libraries and Frameworks

• Spring boot 2.3.9.RELEASE:

  • Spring-boot-starter-web
  • Spring-boot-starter-data-jpa
  • Spring-boot-starter-security
  • Spring-boot-starter-actuator

• Spring cloud Hoxton.SR10

  • Spring Cloud Gateway
  • Spring Cloud Openfeign
  • Spring Cloud Config
  • Spring Cloud Netflix
    • spring-cloud-starter-netflix-ribbon
    • spring-cloud-starter-netflix-eureka-client
    • spring-cloud-starter-netflix-ribbon
  • resilience4j-spring-boot2
  • spring-cloud-starter-stream-rabbit
  • spring-cloud-stream-binder-rabbit

Project structure

How to run in local

• Install docker engine in local, to ease to install RabbitMQ, MySQL server.
• Install MySQL: Please refer: https://dev.mysql.com/doc/mysql-installation-excerpt/8.0/en/docker-mysql-getting-started.html
• Install RabbitMQ:

docker run -d --hostname my-rabbit --name rabbit-local -p 5671-5672:5671-5672 -p 15671-15672:15671-15672 -p 25672:25672 -p 4369:4369 rabbitmq:3-management

• Build all projects in voucher-data folder: mvn clean install
• For each jar file built inside target, run below command to start service, example:

nohup java -jar discovery-service.jar &

• Note: These properties are required to start services:

For voucher-services, otp-services: spring.datasource.url= jdbc url pointing to mysql database spring.datasource.username= database credential username spring.datasource.password= database credential password

CURL commands

• Get voucher, assume orderId was issued after payment has been done.

curl --header "Content-Type: application/json"
--request POST
--data '{"orderId":"xyz","phoneNo":"012345689"}'
http://localhost:7777/voucher-service/get-voucher

• List purchased voucher by phone number. Initial API, server will send OTP to the phone.

curl --header "Content-Type: application/json"
--request POST
--data '{"phoneNo":"012345689"}'
http://localhost:7777/voucher-service/list-voucher

• After user receives OTP, client uses this API to request list of purchased vouchers

curl --header "Content-Type: application/json"
--request POST
--data '{"phoneNo":"012345689", "otp": {"code":"otp_received", "refNo": "ref_no_returned_by_initial_api"}}'
http://localhost:7777/voucher-service/list-voucher

Remaining Task Lists

• API gateway
• Config service
• Unit test coverage