This is simple microservice application designed to illustrate the basic concept of Microservice Architecture and to provide a starting point for future development of any business application.
This microservice application produces a 'Hello World' messages in JSON format. The second part of the message is replaceable and configurable based on a value in the property file. For example, if the property file is updated and the word 'World ' is replaced with 'Java', the service starts producing 'Hello Java' message.
The business logic is located in two Microservices:
| Microservice Name | Location | Description |
|---|---|---|
| HelloWorld Service | /helloworld_service | The main service. It receives client requests, calls GetName service to get the second part of the greeting message, builds the whole message and returns it to the client in JSON format. Note: A Circuit Breaker is used in the GetName call. |
| GetName Service | /getname_service | Provides the second part of the 'Hello World' message from /config_dir/getname-service.properties file. |
This implementation is based on Spring Boot v2.2.2 and Spring Cloud Netflix frameworks.
There are several ways to deploy these microservices. The easiest way is to run them on a local machine as normal Java applications.
Here is preferable order to start these microservices with user interface or endpoint URLs:
| Microservice Name | Location | Access URL | Description |
|---|---|---|---|
| Discovery Service (Eureka) | /eureka_service | http://localhost:8761/ | Provides registration, discovery and load balancing functionality for the other microservices. |
| Config Service | /config_service | N/A | Provides microservices with externalized configuration information. |
| Admin Service | /admin_service | http://localhost:8080/ | Provides a user interface for for managing and monitoring all microservices within the stack. |
| GetName Service | /getname_service | http://localhost:8887/ | Functional microservice. Retrieves the second part of the 'Hello World' message. |
| HelloWorld Service | /helloworld_service | http://localhost:8886/ | The main functional microservice. Produces a 'Hello World' messages in JSON format. This endpoint URL is accessible from within the microservices stack. |
| Gateway Service | /gateway_service | http://localhost:9000/ | Provides an access to HelloWorld Service endpoint from outside of microservices stack. Usually, for security reason the only open port in the firewall is the port of the Gateway Service. |