Enterprise Distributed Application Service:Manage application configurations

How the Data ID maps to your application

The Data ID follows this naming convention:

${prefix}-${spring.profiles.active}.${file-extension}

In this tutorial, the application name is nacos-config-example with no active profile, so the Data ID is nacos-config-example.properties.

3a. Create a Maven project

Create a Maven project named nacos-config-example.

3b. Add dependencies

Add the following to pom.xml. This example uses Spring Boot 2.1.4.RELEASE with Spring Cloud Greenwich.SR1:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.4.RELEASE</version>
    <relativePath/>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        <version>2.1.1.RELEASE</version>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Greenwich.SR1</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

3c. Create the startup class

Under src/main/java, create the package com.aliware.edas and add the following NacosConfigExampleApplication class:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

3d. Create a controller

In the same package, create an EchoController class. The @RefreshScope annotation enables dynamic configuration refresh: when test.name changes in Nacos, the application picks up the new value without a restart.

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

@RestController
@RefreshScope
public class EchoController {

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

    @RequestMapping(value = "/")
    public String echo() {
        return userName;
    }
}

3e. Configure the Nacos Server address

Under src/main/resources, create a bootstrap.properties file:

spring.application.name=nacos-config-example
server.port=18081
spring.cloud.nacos.config.server-addr=127.0.0.1:8848

• 127.0.0.1:8848 -- the Nacos Server address.

• 18081 -- the application port.

If Nacos Server runs on a different machine, update the address and port. See Configuration reference for additional properties.

Verify the initial configuration

1. Run the main method in NacosConfigExampleApplication to start the application.

2. Open http://127.0.0.1:18081 in a browser. The response is nacos-config-test -- the value of test.name that you set in Step 2.

Verify dynamic configuration refresh

1. In the Nacos Server console, go to ConfigManagement > Configurations and edit the nacos-config-example.properties entry.

2. Change test.name=nacos-config-test to test.name=nacos-config-updated and click Publish.

3. Refresh http://127.0.0.1:18081. The response now shows nacos-config-updated, confirming that @RefreshScope works without an application restart.

5a. Create the configuration in EDAS

1. Log on to the EDAS console.

2. In the left-side navigation pane, choose Application Management > Microservice Configurations.

3. On the Configurations page, select a Region in the top navigation bar and a Microservices Namespace from the dropdown. Then click Create Configuration.

4. In the Create Configuration panel, set the same parameters as the local Nacos configuration and click Create:

   Parameter	Value
   Data ID	nacos-config-example.properties
   Group	DEFAULT_GROUP
   Format	Properties
   Configuration Content	test.name=nacos-config-test

5b. Deploy the application

Deploy the application to EDAS. Choose a deployment method based on your infrastructure:

• Deploy to ECS

• Deploy to Kubernetes