ServiceComb使用Consul开源开发任务总结

简介

Apache ServiceComb Java Chassis 给开发者提供一个快速构建微服务的JAVA SDK。它包含如下特性：

1. 基于Open API的契约优先(API First)开发模式，满足开发过程可管理、开发规范可验证要求。
2. 多种开发风格，REST(JAX-RS、Spring MVC）和RPC等，高效支持遗留系统迁移和新系统开发场景。
3. 多种通信协议, HTTP over Vert.x、Http Over Servlet、Highway等，满足不同场景对于性能、韧性的需求。
4. 统一一致的服务提供者、服务消费者处理链，易于扩展新功能。
   提供服务发现、配置管理、熔断、限流、灰度发布等开箱即用的服务治理能力。

在github上Fork servicecomb-java-chassis 代码，并下载代码

consul服务注册、发现实现

1. 创建registry-consul模块：
   
2. 在pom中添加相关依赖，与consul有关的依赖如下：

   <dependency>
     <groupId>org.kiwiproject</groupId>
     <artifactId>consul-client</artifactId>
     <version>1.4.2</version>
   </dependency>
   

3. 实现注册功能
   1）构建ConsulRegistrationInstance实例：consulInstance
   2）利用consulInstance的信息构建NewService的实例newServie
   3）使用consul-api提供的方法注册newServie
   示例代码如下：

   @Override
   public ConsulRegistrationInstance getMicroserviceInstance() {
   	return new ConsulRegistrationInstance(consulInstance);
   }
   @Override
   public void init() {
       String instanceId = registrationId.getInstanceId();
   consulInstance = new ConsulInstance();
   consulInstance.setInstanceId(instanceId);
   consulInstance.setEnvironment(env); consulInstance.setApplication(BootStrapProperties.readApplication(environment)); consulInstance.setServiceName(BootStrapProperties.readServiceName(environment));
   }
   @Override
   public void run() {
       LOGGER.info("ConsulRegistration run");
   ImmutableRegistration.Builder registrationBuilder = ImmutableRegistration.builder()
       .name(consulInstance.getServiceName());
   List<String> endpoints = consulInstance.getEndpoints();
   for (String endpoint : endpoints) {
     Endpoint temp = EndpointUtils.parse(endpoint);
     if (temp.getAddress() instanceof URIEndpointObject) {
       String hostOrIp = ((URIEndpointObject) temp.getAddress()).getHostOrIp();
       int port = ((URIEndpointObject) temp.getAddress()).getPort();
       String serviceId = hostOrIp + ":" + port;
       consulDiscoveryProperties.setServiceId(serviceId);
       consulInstance.setServiceId(serviceId);
       registrationBuilder.id(serviceId);
       registrationBuilder.address(hostOrIp);
       registrationBuilder.port(port);
       break;
     }
   }
   List<String> tags = consulDiscoveryProperties.getTags();
   if (CollectionUtils.isEmpty(tags)) {
     tags.add(consulInstance.getServiceName());
   }
   registrationBuilder.tags(tags);
   Gson gson = new GsonBuilder().disableHtmlEscaping().create();
   Map<String, String> meta = new HashMap<>();
   meta.put("meta", gson.toJson(consulInstance));
   registrationBuilder.meta(meta);
   ImmutableRegistration newService = registrationBuilder.build();
   AgentClient agentClient = consulClient.agentClient();
   agentClient.register(newService);
   LOGGER.info("ConsulRegistration newService");
   }
   

4. 实现服务发现功能
   1） 查找Consul中的Service实例
   2） 将Consul的Service实例转换为ConsulInstance，示例代码如下：

   @Override
   public List<ConsulDiscoveryInstance> findServiceInstances(String application, String serviceName) {
     logger.info("findServiceInstances application: {}, serviceName: {}", application, serviceName);
     consulDiscoveryInstanceList = getInstances(serviceName);
   return consulDiscoveryInstanceList;
   }
   
   public List<ConsulDiscoveryInstance> getInstances(@NotNull final String serviceName) {
   List<ConsulDiscoveryInstance> instances = new ArrayList<>();
   addInstancesToList(instances, serviceName);
   return instances;
   }
   
   private void addInstancesToList(List<ConsulDiscoveryInstance> instances, String serviceName) {
   List<ServiceHealth> healthServices = getHealthServices(serviceName);
   if (!CollectionUtils.isEmpty(healthServices)) {
     for (ServiceHealth serviceHealth : healthServices) {
       Service service = serviceHealth.getService();
       Gson gson = new GsonBuilder().disableHtmlEscaping().create();
       ConsulInstance consulInstance = gson.fromJson(service.getMeta().get("meta"), ConsulInstance.class);
       instances.add(new ConsulDiscoveryInstance(consulInstance));
     }
   }
   }
   
   private List<ServiceHealth> getHealthServices(String serviceName) {
   HealthClient healthClient = consulClient.healthClient();
   return healthClient.getHealthyServiceInstances(serviceName).getResponse();
   }
   

consul配置中心实现

1. 新建config-consul模块
   
2. 在pom中添加相关依赖，与consul有关的依赖如下

   <dependency>
     <groupId>org.kiwiproject</groupId>
     <artifactId>consul-client</artifactId>
     <version>1.4.2</version>
   </dependency>
   

3. 实现配置中心功能
   1）创建ConsulConfigClient,示例代码：

   public ConsulConfigClient consulConfigClient(Environment environment) {
     ConsulConfigProperties consulConfigProperties = consulConfigProperties(environment);
     ConsulClient consulClient = consulClient(consulConfigProperties, consulRawClientBuilderSupplier());
     return new ConsulConfigClient(updateHandler, environment, consulConfigProperties, consulClient);
   }
   
   @Override
   public PropertySource<?> create(Environment environment) {
     try {
       consulConfigClient = consulConfigClient(environment);
       consulConfigClient.refreshConsulConfig();
     } catch (Exception e) {
       throw new IllegalStateException("Set up consul config failed.", e);
     }
     return new MapPropertySource(SOURCE_NAME, valueCache);
   }
   

4. 在ConsulConfigClient中实现key-value的读取，示例代码如下：

   private Map<String, Object> getValues(String path) {
     Map<String, Object> values = new HashMap<>();
     KeyValueClient keyValueClient = consulClient.keyValueClient();
     String decodedValue = keyValueClient.getValueAsString(path).orElseThrow();
     if (StringUtils.isBlank(decodedValue)) {
       return values;
     }
     return getValues(path, decodedValue);
   }
   
   private @NotNull Map<String, Object> getValues(String path, String decodedValue) {
     Map<String, Object> values = new HashMap<>();
     if (path.endsWith(".yaml") || path.endsWith(".yml")) {
       YamlPropertiesFactoryBean yamlFactory = new YamlPropertiesFactoryBean();
       yamlFactory.setResources(new ByteArrayResource(decodedValue.getBytes(StandardCharsets.UTF_8)));
       values.putAll(toMap(yamlFactory.getObject()));
     } else if (path.endsWith(".properties")) {
       Properties properties = new Properties();
       try {
         properties.load(new StringReader(decodedValue));
       } catch (IOException e) {
         LOGGER.error(e.getMessage(), e);
       }
       values.putAll(toMap(properties));
     } else {
       values.put(path, decodedValue);
     }
     return values;
   }
   

5. 自动获取最新内容，示例代码：

   try (KVCache cache = KVCache.newCache(kvClient, path, consulConfig.getConsulWatchSeconds())) {
     cache.addListener(newValues -> {
       Optional<Value> newValue = newValues.values().stream()
           .filter(value -> value.getKey().equals(path))
           .findAny();
   
       newValue.ifPresent(value -> {
         Optional<String> decodedValue = newValue.get().getValueAsString();
         decodedValue.ifPresent(v -> new Thread(new GetDataRunnable("environmentData", getValues(path))).start());
       });
     });
     cache.start();
   }
   

功能测试

1. 在demo模块下新建demo-consul模块，用户consul测试
   
2. 编写完测试用例后,启动provider、gateway、consumer
3. 启动test-client
4. test-client运行完成后，观察控制台输出，没有输出测试相关错误的，表示测试通过

代码检查

1. 代码检查要执行的命令
   
2. 在本地执行除maven.yml文件的，有关maven命令和其它命令，需要安装插件或工具的自行参考有关工具的安装使用方法
3. 执行maven.yml，由于在此过程中需要下载镜像，需要在能访问到有关镜像的机器上执行，同时要注意修改 test-client的pom.xml配置，使应用能够访问到对应的镜像里面的服务

提交代码

• 功能测试和代码检查都通过后，就可以提交代码了，代码提交的消息参考github代码提交规范

提交PR

1. 在github代码仓库页面发起 Pull Request
   
2. 提交PR后，告知相关人员执行代码检查

修复代码检视中发现的错误

1. 提交PR后，相关人员会对代码进行检视，并提出修改意见
2. 根据修改意见修改代码，并重新提交代码
3. 重复以上步骤，直至代码被合并