Spring Boot Microservices — Part3— config-server and RefreshScope with RabbitMQ

Prateek
5 min readMay 7, 2022

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In this example, we’ll look at the way to refresh the configuration (in the distributed configuration) dynamically using the RabbitMQ.

Steps to Setup RabbitMQ using Docker:

if you launched rabbitmq by using somthing like:

docker run -d --name some-rabbit -p 4369:4369 -p 5671:5671 -p 5672:5672 -p 15672:15672 rabbitmq

then you can enable its management plugins while that container runs using the following command:

docker container exec -it some-rabbit rabbitmq-plugins enable rabbitmq_management

and the management GUI is running on http://localhost:15672 For management GUI

username: guest / password: guest

product-service

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"
>
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.6.7</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>

<properties>
<java.version>11</java.version>
<spring-cloud.version>2021.0.2</spring-cloud.version>
</properties>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bus-amqp</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>

</project>

application.properties

spring.data.mongodb.uri=mongodb://localhost:27017/product-service

spring.application.name
=product-service
server.port
=0
eureka.instance.instance-id
=${spring.application.name}:${random.uuid}

#https://docs.spring.io/spring-cloud-config/docs/current/reference/html/
spring.config.import=optional:configserver:http://localhost:8888?fail-fast=true&max-attempts=10&max-interval=1500
management.endpoints.web.exposure.include=*

#RabbitMQ
spring.rabbitmq.host=localhost
spring.rabbitmq.port
=5672
spring.rabbitmq.username
=guest
spring.rabbitmq.password
=guest

Product.java

package com.example.model;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;

import java.math.BigDecimal;

@AllArgsConstructor
@NoArgsConstructor
@Data
@Builder
@Document(value = "product")
public class Product {
@Id
private String id;
private String name;
private String description;
private BigDecimal price;
}

ProductRepository.java

package com.example.repository;

import com.example.model.Product;
import org.springframework.data.mongodb.repository.MongoRepository;

public interface ProductRepository extends MongoRepository<Product, String> {
}

TestController.java

package com.example.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/test")
@RefreshScope
public class TestController {

@Value("${test.name}")
private String name;

@GetMapping
public String test() {
return name;
}
}

ProductController.java

package com.example.controller;

import com.example.model.Product;
import com.example.repository.ProductRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/api/product")
@RequiredArgsConstructor
public class ProductController {
private final ProductRepository productRepository;

@GetMapping
@ResponseStatus(HttpStatus.OK)
public List<Product> findAll() {
return productRepository.findAll();
}

@PostMapping
@ResponseStatus(HttpStatus.CREATED)
public void createProduct(@RequestBody Product product) {
productRepository.save(product);
}
}

MainApp.java

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class ProductServiceApplication {

public static void main(String[] args) {
SpringApplication.run(ProductServiceApplication.class, args);
}
}

Start the product-service MainApp

order-service

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"
>
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.6.7</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>order-service</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>order-service</name>
<description>Demo project for Spring Boot</description>

<properties>
<java.version>11</java.version>
<spring-cloud.version>2021.0.2</spring-cloud.version>
</properties>


<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bus-amqp</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>

<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
</project>

OrderDto.java

package com.example.dto;

import com.example.model.OrderLineItems;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.List;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class OrderDto {
private List<OrderLineItems> orderLineItemsList;
}

Order.java

package com.example.model;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

import javax.persistence.*;
import java.util.List;

@Entity
@Table(name = "t_orders")
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
public class Order {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String orderNumber;
@OneToMany(cascade = CascadeType.ALL)
private List<OrderLineItems> orderLineItems;
}

OrderLineItems.java

package com.example.model;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

import javax.persistence.*;
import java.math.BigDecimal;

@AllArgsConstructor
@NoArgsConstructor
@Getter
@Setter
@Entity
@Table(name = "order_line_items")
public class OrderLineItems {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String skuCode;
private BigDecimal price;
private Integer quantity;
}

application.properties

#MySQL DB
spring.datasource.username=root
spring.datasource.password
=password

# Need to look at the ways to

spring.application.name=order-service
server.port
=0
eureka.instance.instance-id
=${spring.application.name}:${random.uuid}
#spring.config.import=optional:configserver:http://localhost:8888?fail-fast=true&max-attempts=10&max-interval=1500
spring.config.import=optional:configserver:http://localhost:8888?fail-fast=true&max-attempts=10&max-interval=1500&vault://secret/order-service

management.endpoints.web.exposure.include
=*

#RabbitMQ
spring.rabbitmq.host=localhost
spring.rabbitmq.port
=5672
spring.rabbitmq.username
=guest
spring.rabbitmq.password
=guest

OrderRepository.java

package com.example.repository;

import com.example.model.Order;
import org.springframework.data.jpa.repository.JpaRepository;

public interface OrderRepository extends JpaRepository<Order, Long> {
}

Now, you can make the below request, changes will be broadcast to the RabbitQM and will be listen by all the services and update the configurations at their end

http://localhost:56481/actuator/busrefresh

When you hit the http://localhost:56915/api/test. (Note: 56915 is port of product-service), I can see the latest value has come.

We can also check the RabbitMQ

http://localhost:56915/api/product

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