spring-cloud-config-server2.0使用ETCD存储配置文件

spring-cloud-config-server2.0使用ETCD存储配置文件

实现目标：使用ETCD来实现spring-cloud-config-server的配置文件存储功能
官方说明参考：https://docs.spring.io/spring-cloud-config/docs/2.2.9.BUILD-SNAPSHOT/reference/html/#_custom_composite_environment_repositories

config-server实现

Spring Boot版本和 Spring cloud版本需要保持一致

• maven版本坐标

   	//仅列出主要版本配置
   
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.10.RELEASE</version>
    </parent>

	<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-config-server</artifactId>
        <version>2.2.2.RELEASE</version>
    </dependency>

	<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

• 创建自定义的属性配置类

@Component
@ConfigurationProperties("spring.cloud.config.server.etcd")
public class EtcdEnvironmentProperties implements EnvironmentRepositoryProperties {

    private int order = Ordered.LOWEST_PRECEDENCE;

    //etcd服务地址
    private String serverUrl;

    public int getOrder() {
        return this.order;
    }

    @Override
    public void setOrder(int order) {
        this.order = order;
    }

    public String getServerUrl() {
        return serverUrl;
    }

    public void setServerUrl(String serverUrl) {
        this.serverUrl = serverUrl;
    }
}

• 实现EnvironmentRepository，并使用注解@Profile("etcd")

@Profile("etcd") //自定义的EnvironmentRepository, 用法application.properties中使用： spring.profiles.active=etcd
@Configuration
public class EtcdEnvironmentRepository implements EnvironmentRepository, Ordered {

    private EtcdClient etcdClient;// EtcdClient的java客户端

    private EtcdEnvironmentProperties etcdEnvironmentProperties; //

    public EtcdEnvironmentRepository(EtcdClient etcdClient, EtcdEnvironmentProperties 	etcdEnvironmentProperties) {
        etcdClient.setUrl(etcdEnvironmentProperties.getServerUrl());
        etcdClient.connect();
        this.etcdClient = etcdClient;
        this.etcdEnvironmentProperties = etcdEnvironmentProperties;
    }

    //此方法为具体实现业务逻辑
    @Override
    public Environment findOne(String application, String profile, String label) {
        String[] profiles = StringUtils.commaDelimitedListToStringArray(profile);
        Environment environment = new Environment(application, profiles, label, null, null);
        final List<String> keys = addKeys(application, profile);
        keys.forEach(it -> {
            environment.add(new PropertySource(it, etcdClient.read2Properties(it)));
        });
        return environment;

    }

    //支持多个profile和 application name 
    private List<String> addKeys(String application, String profile) {
        List<String> keys = new ArrayList<>();
        String[] apps = StringUtils.commaDelimitedListToStringArray(application);
        String[] profiles = StringUtils.commaDelimitedListToStringArray(profile);
        for (String prof : profiles) {
            for (String app : apps) {
                keys.add(app + "-" + prof + ".properties");
            }
        }
        return keys;
    }

    @Override
    public int getOrder() {
        return etcdEnvironmentProperties.getOrder();
    }
}

• 配置文件

spring.application.name=config-server
server.port=1202
eureka.client.register-with-eureka=false
spring.profiles.active=etcd #重要，指定使用etcd，EtcdEnvironmentRepository为实现类
spring.cloud.config.server.etcd.serverxx-url=http://ip:2379

客户端使用

• maven坐标

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.10.RELEASE</version>
</parent>
<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-config</artifactId>
</dependency>

• application配置

spring.cloud.config.profile=dev,public  #支持多个profile
spring.cloud.config.name=demo-service,demo-mysql,demo-amq #支持多个配置文件
spring.cloud.config.uri=http://ip:port #config-server地址

写在最后

1. 如上写法仅支持 properties文件，yml等其他格式支持，需药etcd的client中做转换
2. 如上实现可以使用Spring cloud生态，使用方法和习惯和官方保持一致
3. 本文仅讨论etdc的实现方式，具体项目实践中，以具体需求为准，不代表etcd优于git、native、jdbc等实现