Connecting Spring Cloud Applications to ServiceComb Engines

This section describes how to connect Spring Cloud applications to ServiceComb engines and use the most common functions of ServiceComb engines. For details about the development guide, see Using ServiceComb Engine Functions.

In the Spring Cloud Huawei Samples project, you can find the code corresponding to the development methods in this section.

Spring Cloud needs to use Spring Cloud Huawei to connect to ServiceComb engines. This document describes how to integrate and use Spring Cloud Huawei in Spring Cloud.

Prerequisites

Microservice applications have been developed based on Spring Cloud.
For details about microservice application development in the Spring Cloud microservice framework, see https://spring.io/projects/spring-cloud.

Version requirements. See Requirements for Microservice Development Framework of a ServiceComb Engine.
This document assumes that you use Maven for dependency management and packaging in your project. You are familiar with the Maven dependency management mechanism and are able to modify the dependency management and dependency in the pom.xml file.

Procedure

Add dependencies to the pom.xml file of the project.

If you develop microservices using Spring Cloud, introduce the following dependencies:

<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-service-engine</artifactId>
</dependency>

The spring-cloud-starter-huawei-service-engine module consists of the following dependent modules:

<!-- Registry and discovery module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-discovery</artifactId>
</dependency>
<!-- Configuration center module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-config</artifactId>
</dependency>
<!-- Service governance module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-governance</artifactId>
</dependency>
<!-- Dark launch module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-router</artifactId>
</dependency>

If you develop the gateway using Spring Cloud, introduce the following dependencies:

<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-service-engine-gateway</artifactId>
</dependency>

The spring-cloud-starter-huawei-service-engine-gateway module consists of the following dependent modules:

<!-- Registry and discovery module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-discovery</artifactId>
</dependency>
<!-- Configuration center module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-config</artifactId>
</dependency>
<!-- Service governance module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-governance</artifactId>
</dependency>
<!-- Dark launch module -->
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-router</artifactId>
</dependency>
<!-- Gateway module -->
<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

You are advised to use Maven Dependency Management to manage the third-party software dependencies of a project. Introduce the following dependencies to the project:

 <dependencyManagement>
    <dependencies>
      <!-- configure user spring cloud / spring boot versions -->
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>${spring-boot.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>${spring-cloud.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <!-- configure spring cloud huawei version -->
      <dependency>
        <groupId>com.huaweicloud</groupId>
        <artifactId>spring-cloud-huawei-bom</artifactId>
        <version>${spring-cloud-huawei.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

Skip the operation if your project already contains the preceding dependencies.

If other registry and discovery libraries, such as Eureka, are used in your project, you need to adjust the project as follows:

Delete the dependencies related to Eureka from the project. For example:

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>

If @EnableEurekaServer is used in the code, delete it and replace it with @EnableDiscoveryClient.
The spring-cloud-starter-huawei-service-engine component provides functions such as service registration, configuration center, service governance, dark launch, and contract management. Contract management is not mandatory for the running of Spring Cloud microservice applications. The ServiceComb engine limits the number of contracts. When the number of microservice application contracts exceeds the limit, the registry fails. If the legacy system cannot be properly split to reduce the number of contracts, the dependency can be excluded and the contract management function is not used.
```
<dependency>
  <groupId>com.huaweicloud</groupId>
  <artifactId>spring-cloud-starter-huawei-service-engine</artifactId>
  <exclusions>
	<exclusion>
	  <groupId>com.huaweicloud</groupId>
	  <artifactId>spring-cloud-starter-huawei-swagger</artifactId>
	</exclusion>
  </exclusions>
</dependency>
```

Configure microservice information.

Add the microservice description to the bootstrap.yml file. If the bootstrap.yml file is not available in the project, create one.

spring:
  application:
    name: basic-provider
  cloud:
    servicecomb:
      discovery:
        enabled: true
        address: http://127.0.0.1:30100
        appName: basic-application
        serviceName: ${spring.application.name}
        version: 0.0.1
        healthCheckInterval: 15
      config:
        serverAddr: http://127.0.0.1:{port}
        serverType: {servertype}

healthCheckInterval is in seconds.
For ServiceComb engine 1.x, {port} is 30103 and {servertype} is config-center.
For ServiceComb engine 2.x, {port} is 30110 and {servertype} is kie (recommended) or config-center.

(Optional) Configure security authentication parameters.

Perform this step only when you use the exclusive ServiceComb engine and enable security authentication. In other scenarios, skip this step.

After security authentication is enabled for a ServiceComb engine, all called APIs can be called only after a token is obtained. For details about the authentication process, see RBAC.

To use security authentication, obtain the username and password from the ServiceComb engine and then add the following configuration to the configuration file.

Configuration in plaintext

spring:
  cloud:
    servicecomb:
      credentials:
        account:
          name: username
          password: password
          cipher: default

Custom encryption algorithms for storage

Implement the com.huaweicloud.common.util.Cipher API using either of the following methods:
String name(), which is the name definition of spring.cloud.servicecomb.credentials.cipher and needs to be added to the configuration file.
char[] decode(char[] encrypted), which is the decryption API used to decrypt secretKey.
public class CustomCipher implements Cipher
To implement encryption and decryption, you need to use BootstrapConfiguration as the startup add-in. Add the following statement first:
@Configuration
public class MyCipherConfiguration {
  @Bean
  public Cipher customCipher() {
    return new CustomCipher();
  }
}
Add the META-INF/spring.factories file to define the configuration:
org.springframework.cloud.bootstrap.BootstrapConfiguration=\
com.huaweicloud.common.transport.MyCipherConfiguration
After the custom configuration is complete, you can use the new decryption algorithm in the bootstrap.yaml file.

spring:
  cloud:
    servicecomb:
      credentials:
        account:
          name: username
          password: password
        cipher: user-defined algorithm name

The RBAC function requires 1.6.0-Hoxton or later.

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