Exploring Microservices

Dependencies

• Java 8
• Spring Boot 1.2.+
• Gradle 2.+

How to run

All services are located in 'services/<service_name>'.

Run service from console type:

$gradle bootRun

Run service from IDE: Each service has Applicatio.java in the root package with main method to run. By that it's possible to easily run service in debug mode.

How to create new microservices

• All microservices are located in services folder.
• All microservices have:

  • Application.java

  • To enable CXP nature, add @EnableCXP annotation to Application class, or any other @Configuration class

  • AppConfiguration.java in root package. Used to expose microservice configuration when is packed with other microservices as monolith WAR. This file is references under META-INF/spring.factories

package ms.services.time;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan(basePackageClasses = { ms.services.time.rest.TimeController.class })
public class AppConfiguration {
// list of used beans
}

Example of spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=ms.monolithic.MonolithicConfiguration

• Register configuration that can be discoverable when microservices is packed in JAR. Create file in project folder: src/main/resources/META-INF/spring.factories. And add a reference to microservice AppConfiguration

org.springframework.boot.autoconfigure.EnableAutoConfiguration=ms.services.time.AppConfiguration

Build JAR/WAR

To build the executable JAR/WAR for each microservice, run gradle command in the service folder. Gradle will create jar and war files inside build/libs

$gradle build

To create a deployable war file for servlet container as Tomcat, WebSphere, etc. execute gradle command, which will create war file inside build/libs. This war file doesn't contain Spring Boot files and other library dependencies to run as standalone war/jar file.

$gradle war

Project structure

• api
• commons
• services
  • calculator
  • time
  • userService (example with one DataSource: user)
  • bankService (example with two DataSources: bank, audit)

HowTo

Enable CXP nature

For enabling CXP nature we simply need to add @EnableCXP annotation to startup class.

Swagger integration

By enabling CXP nature with @EnableCXP there is also Swagger integration for automate documenting RESTfull API. To access Swagger use this URL's: http://localhost:8080/swagger-ui.html and http://localhost:8080/v2/api-docs/

Features

• Support for nesting properties file inside monolithic build with microservice namespace. Support to target specific property value for specific microservice
• Support for custom creating DataSource and merging datasource (for monolithic build)