Microservices with springcloud

This project demonstrates microservices architectural pattern using the spring boot and spring cloud.

Spring cloud compnents:

Eureka Server - Open source service discovery server.

Microservices
- Product Service
- Coupon Service
Zuul API gateway
- Helps put all the crossing cutting concerns in one single place like security,tracing and service aggregation and rate limits.
- Zuul is just another microservice and it will register itself with Eureka.
- API gateway as a single point of entry for all front end clients.
- Zuul automatically gives us server side load balancing using Ribbon internally.
- When invoking microservices from front end clients like Angular, invoke using this format https://<servername>:8765/microservice-name/uri where 8765 is port for Zuul gateway server and microservice name is the name of the microservice registered under the Eureka naming server.

Feign
- Develop rest clients using Feign instead of RestTemplate.
- Eg. Coupon service is invoked from Product Service using Feign.
- Helps avoid hardcoding of URLs.
Hystrix
- Used for fault tolerance.
- Is integrated within the product service.If coupon service is down, then product service handles errors gracefully.
- Sleuth and Zipkin
```
 * Used for request tracking.
 
 * Zipkin provides a dashboard to view the trace of a http request.
```

Config Server
- Used for centralized configuration management
- Requires the installation and running of Rabbit MQ .
- Can refresh client properties for all microservice instances by using the actuator endpoint - http://localhost:9090/actuator/bus-refresh