Microshop

Microshop is a sample microservices application based on Spring technologies such as Boot 2, Framework 5, Cloud (Config, Netflix, Gateway, etc), Data and others.

Requires Java 8+ and Maven 3.5+.

Features

Currently implemented :

• Two basic business services with an in-memory H2 database
• Common utility module with logs of slow HTTP requests
• Config server, based on Spring Cloud Config
• Service registry, based on Spring Cloud Netflix Eureka
• API gateway, based on Spring Cloud Gateway
• Client load balancing, based on Spring Cloud Netflix Ribbon
• Circuit breaker, based on Spring Cloud Netflix Hystrix
• Circuit breaker dashboard, based on Spring Cloud Netflix Hystrix Dashboard
• Distributed tracing, based on Spring Cloud Zipkin and Zipkin server
• Configurable tracing of business methods
• Admin interface, based on Spring Boot Admin
• Docker and Docker Compose support
• Postman support

Services

The business services:

• microshop-order:
  • Purchase orders, uses the stock service
  • Uses an embedded in-memory H2 database that is reset each time the service starts
  • Spring Boot app on port 8081 by default
• microshop-stock:
  • Articles stock, used by the order service
  • Uses an embedded in-memory H2 database that is reset each time the service starts
  • Spring Boot app on port 8082 by default

The technical services:

• microshop-config:
  • Config server, centralizes the configuration of the other services
  • Spring Boot app on port 8888 by default, based on Spring Cloud Config
• microshop-registry:
  • Registry server, records instances of business services
  • Spring Boot app on port 8761 by default, based on Spring Cloud Netflix Eureka
• microshop-gateway:
  • API gateway, routes requests to business services
  • Spring Boot app on port 8080 by default, based on Spring Cloud Gateway
• microshop-admin:
  • Optional admin interface for Spring Boot applications
  • Spring Boot app on port 8090 by default, based on Spring Boot Admin
• microshop-dashboard:
  • Optional Hystrix dashboard, displays circuit breakers stats
  • Spring Boot app on port 7979 by default, based on Spring Cloud Netflix Hystrix Dashboard
• microshop-zipkin:
  • Optional Zipkin UI, displays distributed traces
  • Spring Boot app on port 9411 by default, based on Zipkin server

Other modules:

• microshop-common:
  • Common utility classes

The rest of this document omits microshop-.

Internal dependencies:

Service	Dependencies
common	-
config	-
registry	config (run)
order	common (build), config (run), registry (run), zipkin (run)
stock	common (build), config (run), registry (run), zipkin (run)
gateway	config (run), registry (run), zipkin (run)
admin	config (run), registry (run)
dashboard	-
zipkin	registry (run)

build means that this a build time dependency, run means that this is called (HTTP or other) during the service execution.

Execution

The application follows the "config first" (rather than "registry first") approach. Meaning that the business services first connect to the config server to get the location of the service registry, then connect to the service registry.

Build all modules with mvn package from the root folder, then execute each module with mvn spring-boot:run (or java -jar target/<service>.jar) from its folder, using this order from first to last: config then registry then the rest in any order.

To launch additional business service instances change the HTTP using for example mvn spring-boot:run -Dspring-boot.run.arguments=--server.port=8083 (or java -jar target/<service>.jar --server.port=8083).

To start the whole application with Docker, build the modules then run docker-compose up from the root folder. Note that, to reduce startup time and memory usage, this will not start all services but only the core ones (config, registry, order, stock, gateway).

The business URL are:

Service	Method	Path	Description
Both	GET	http://localhost:8080/api/reset	Reset all business data
Order	GET	http://localhost:8080/api/orders	Get all orders
Order	GET	http://localhost:8080/api/orders/{id}	Get an order
Order	POST	http://localhost:8080/api/orders	Create a new order and update the stock
Stock	GET	http://localhost:8080/api/articles	Get all articles
Stock	GET	http://localhost:8080/api/articles/{id}	Get an article
Stock	PUT	http://localhost:8080/api/articles	Update an article

In addition the technical URL are:

URL	Description
http://localhost:8888/order/default	Configuration of Order
http://localhost:8761/	Service registry UI
http://localhost:8761/eureka/apps/order	Service registry records of Order
http://localhost:8090/	Spring Boot Admin UI
http://localhost:7979/hystrix	Hystrix Dashboard, then use http://localhost:8081/actuator/hystrix.stream
http://localhost:9411/zipkin	Zipkin UI

A Postman configuration file is also provided for convenience in the postman folder.

Next steps

Not yet implemented:

• Replace Ribbon by Spring Cloud Loadbalancer
• Replace Hystrix by Resilience4j, but Resilience4j fallback management is not so great
• Hot configuration reload
• Technical services security
• Business services security