Serverless App Engine:Manage application configurations

Step 1: Use Nacos Config to manage application configurations

1. Create a Maven project named nacos-config-example.

2. Add dependencies to the pom.xml file.

   In this example, Spring Boot 2.1.4.RELEASE and Spring Cloud Greenwich.SR1 are used.

   <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>                        

   In this example, Spring Cloud Greenwich is used. The version of Spring Cloud Alibaba for Spring Cloud Greenwich is 2.1.1.RELEASE.

   • The version of Spring Cloud Alibaba for Spring Cloud Finchley is 2.0.1.RELEASE.

   • The version of Spring Cloud Alibaba for Spring Cloud Edgware is 1.5.1.RELEASE.

   Note

   Spring Cloud Edgware is discontinued. We recommend that you do not use Spring Cloud Edgware to develop applications.

3. In src\main\java, create the com.aliware.edas package.

4. In the com.aliware.edas package, create the NacosConfigExampleApplication startup class for the nacos-config-example project.

       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);
           }
       }                        

5. In the com.aliware.edas package, create the simple EchoController controller. The userName property is automatically injected. Then, add the @Value annotation to obtain the value of the test.name key from the configuration.

       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;
           }
       }                        

6. In the src\main\resources directory, create the bootstrap.properties configuration file. In the bootstrap.properties file, add the following configuration items to specify the address of Nacos Server.

   In the following configuration items, 127.0.0.1:8848 is the address of Nacos Server, and 18081 is the service port.

   If your Nacos Server is deployed on another machine, change the IP address and port to the relevant ones. If you have other requirements, add the relevant configuration items in the bootstrap.properties file. For more information, see Configuration items for reference.

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

7. Run the main function in the NacosConfigExampleApplication class to start the application.

Step 2: Deploy the application on SAE

After you develop and test your application in an on-premises environment, you can deploy the application on SAE. For more information, see Deploy applications.

• The configuration management center of SAE provides the official commercial version of Nacos Server. When you deploy an application on SAE, SAE specifies the following information at a higher priority: the IP address and the service port of Nacos Server, namespace, access-key, secret-key, and context-path. You do not need to configure additional settings. You can retain or delete the original configurations.

• The first time you deploy an application in the SAE console, you must set the Application Runtime Environment parameter to Standard Java Application Runtime Environment if you select Deployment with JAR Packages when you create the application.

  

Before you deploy the application, use the configuration management feature of SAE to create the same application configurations as those in on-premises Nacos Server.

1. Log on to the SAE console. In the left-side navigation pane, click Namespace, and then select a region in the top menu bar.

2. On the Namespace page, click the name of the desired namespace.

3. On the page that appears, choose Distributed Configuration Management > Configurations in the left-side navigation pane. On the Configurations page, click Create Configuration.

4. In the Create Configuration panel that appears, configure the parameters, and click Create. The following table describes the parameters.

   Parameter	Description
   Data ID	The ID of the configuration. In this example, nacos-config-example.properties is specified. To ensure that the ID is globally unique, specify an ID in the format that follows the package.class naming convention. Example: com.taobao.tc.refund.log.level. We recommend that you set the class parameter to a configuration name that has a business meaning.
   Group	The name of the configuration group. In this example,DEFAULT_GROUP is used. To ensure that the group name is globally unique, we recommend that you specify a group name in the product name:module name format. Example: ACM:Test. You can perform authentication by group.
   Data Encryption	Specifies whether to encrypt the configuration data. If your configuration contains sensitive data, we recommend that you enable the data encryption feature to prevent the sensitive data from being leaked. Important Before you can enable the data encryption feature, you must activate Key Management Service (KMS) and grant ACM the permissions to use KMS for data encryption and decryption. The data encryption feature of ACM depends on KMS. You must activate KMS and grant the required permissions to ACM. The Data ID of an encrypted configuration starts with cipher-. For more information, see Create and use an encrypted configuration file.
   Configuration Format	The format of the configuration content. In this example, TEXT is selected.
   Configuration Content	The configuration content. In this example, test.name=nacos-config-test is specified.
   Configuration Description	The description of the configuration.
   More Configuration
   Application	The name of the application to which the configuration belongs.
   Label	The labels. You can manage configurations by label. You can add up to five labels.

Step 3: Verify the result

After you deploy an application, you can view the related logs to check whether the application is started.

1. Run the curl http://<application instance IP>:<service port> command.

   For example, you can run the curl http://192.168.0.34:8080 command to check whether the configuration content nacos-config-test is returned.

2. Log on to the SAE console, change the original configuration content to nacos-config-test2, and then run the curl http://<application instance IP>:<service port> command.

   For example, you can run the curl http://192.168.0.34:8080 command to check whether the new configuration content nacos-config-test2 is returned.

Configuration items for reference

If you have other requirements, you can refer to the following table and add configuration items to the bootstrap.properties file.

For more information about the configuration items, see the open source Spring Cloud Alibaba Nacos Config documentation.