Spring Cloud 学习(29) --- Spring Cloud Config(四) Spring Cloud 配置、高可用

xiaoxiao2022-07-12 181

本地参数覆盖远程参数

spring: cloud: config: allow-override: true override-none: true override-system-properties: false allow-override：标识 override-system-properties 是否启用，默认为 true，设置为 false 时，意味着禁用用户的设置override-none：当此项为 true，override-override 为 true，外部的配置优先级更低，而且不能覆盖任何存在的属性源。默认为 falseoverride-system-properties：用来标识外部配置是否能够覆盖系统配置，默认为 true @ConfigurationProperties("spring.cloud.config") public class PropertySourceBootstrapProperties { private boolean overrideSystemProperties = true; private boolean allowOverride = true; private boolean overrideNone = false; public PropertySourceBootstrapProperties() { } // 省略 getter、setter }

客户端功能扩展

客户端自动刷新

源码：https://gitee.com/laiyy0728/spring-cloud/tree/master/spring-cloud-config/spring-cloud-autoconfig

在有些应用上，不需要再服务端批量推送的时候，客户端本身需要获取变化参数的情况下，使用客户端的自动刷新能完成此功能。

config server 依然采用 spring-cloud-config-simple-server，基础配置不变，配置文件 repo 依然是 https://gitee.com/laiyy0728/config-repo

配置拉取、刷新二方库

新建一个二方库（spring-cloud-autoconfig-refresh），用于其他项目引入，以自动刷新配置（用于多个子项目使用同一个配置中心，自动刷新）

<dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-config-client</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-autoconfigure</artifactId> </dependency> </dependencies>

整个二方库只有这一个类，作用是获取定时刷新时间，并刷新配置

@Configuration @ConditionalOnClass(RefreshEndpoint.class) @ConditionalOnProperty("spring.cloud.config.refreshInterval") @AutoConfigureAfter(RefreshAutoConfiguration.class) @EnableScheduling public class SpringCloudAutoconfigRefreshApplication implements SchedulingConfigurer { private static final Logger LOGGER = LoggerFactory.getLogger(SpringCloudAutoconfigRefreshApplication.class); @Autowired public SpringCloudAutoconfigRefreshApplication(RefreshEndpoint refreshEndpoint) { this.refreshEndpoint = refreshEndpoint; } @Value("${spring.cloud.config.refreshInterval}") private long refreshInterval; private final RefreshEndpoint refreshEndpoint; @Override public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) { final long interval = getRefreshIntervalilliseconds(); LOGGER.info(">>>>>>>>>>>>>>>>>>>>>> 定时刷新延迟 {} 秒启动，每 {} 毫秒刷新一次配置 <<<<<<<<<<<<<<<<", refreshInterval, interval); scheduledTaskRegistrar.addFixedDelayTask(new IntervalTask(refreshEndpoint::refresh, interval, interval)); } /** * 返回毫秒级时间间隔 */ private long getRefreshIntervalilliseconds() { return refreshInterval * 1000; } }

/resources/META-INF/spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\ com.laiyy.gitee.config.springcloudautoconfigrefresh.SpringCloudAutoconfigRefreshApplication

客户端引入二方库

创建客户端项目(spring-cloud-autoconfig-client)

<dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-config-client</artifactId> </dependency>  <dependency> <groupId>com.laiyy.gitee.config</groupId> <artifactId>spring-cloud-autoconfig-refresh</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> </dependencies>

bootstrap.yml

spring: cloud: config: uri: http://localhost:9090 label: master name: config-simple profile: dev

application.yml

server: port: 9091 spring: application: name: spring-cloud-autoconfig-client cloud: config: refreshInterval: 10 # 延迟时间、定时刷新时间

其余配置与 spring-cloud-config-simple-client 一致

验证

启动项目，访问 http://localhost:9090/get-config-info ，正常返回信息。修改 config repo 配置文件，等待 10 秒后，再次访问，可见返回信息已经变为修改后信息。查看 client 控制台，可见定时刷新日志

Exposing 2 endpoint(s) beneath base path '/actuator' >>>>>>>>>>>>>>>>>>>>>> 定时刷新延迟 10 秒启动 No TaskScheduler/ScheduledExecutorService bean found for scheduled processing Tomcat started on port(s): 9091 (http) with context path '' Started SpringCloudAutoconfigClientApplication in 4.361 seconds (JVM running for 5.089) Initializing Spring DispatcherServlet 'dispatcherServlet' Initializing Servlet 'dispatcherServlet' Fetching config from server at : http://localhost:9090 ------------------ 第一次请求 Completed initialization in 7 ms Located environment: name=config-simple, profiles=[dev], label=master, version=00324826262afd5178a648a469247f4fffea945e, state=null Bean 'org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration' of type [org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration$$EnhancerBySpringCGLIB$$f67277ed] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying) Fetching config from server at : http://localhost:9090 ------------------ 定时刷新配置 Located environment: name=config-simple, profiles=[dev], label=master, version=00324826262afd5178a648a469247f4fffea945e, state=null Located property source: CompositePropertySource {name='configService', propertySources=[MapPropertySource {name='configClient'}, MapPropertySource {name='https://gitee.com/laiyy0728/config-repo/config-simple/config-simple-dev.yml'}]} ... 省略其他多次刷新

客户端回退

客户端回退机制，可以在出现网络中断时、或者配置服务因维护而关闭时，使得客户端可以正常使用。当启动回退时，客户端适配器将配置“缓存”到计算机中。要启用回退功能，只需要指定缓存存储的位置即可。

源码：https://gitee.com/laiyy0728/spring-cloud/tree/master/spring-cloud-config/spring-cloud-config-fallback

config server 依然采用 spring-cloud-config-simple-server，基础配置不变，配置文件 repo 依然是 https://gitee.com/laiyy0728/config-repo

二方库

<dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-rsa</artifactId> <version>1.0.7.RELEASE</version> </dependency> </dependencies>

config-client.properties：用于设置是否开启配置

spring.cloud.config.enabled=false

/resources/META-INF/spring.factories

org.springframework.cloud.bootstrap.BootstrapConfiguration=\ com.laiyy.gitee.config.springcloudconfigfallbackautorefresh.ConfigServerBootStrap // 用于拉取远程配置文件，并保存到本地 @Order(0) public class FallbackableConfigServerPropertySourceLocator extends ConfigServicePropertySourceLocator { private static final Logger LOGGER = LoggerFactory.getLogger(FallbackableConfigServerPropertySourceLocator.class); private boolean fallbackEnabled; private String fallbackLocation; @Autowired(required = false) private TextEncryptor textEncryptor; public FallbackableConfigServerPropertySourceLocator(ConfigClientProperties defaultProperties, String fallbackLocation) { super(defaultProperties); this.fallbackLocation = fallbackLocation; this.fallbackEnabled = !StringUtils.isEmpty(fallbackLocation); } @Override public PropertySource<?> locate(Environment environment){ PropertySource<?> propertySource = super.locate(environment); if (fallbackEnabled && propertySource != null){ storeLocally(propertySource); } return propertySource; } /** * 转换配置文件 */ private void storeLocally(PropertySource propertySource){ StringBuilder builder = new StringBuilder(); CompositePropertySource source = (CompositePropertySource) propertySource; for (String propertyName : source.getPropertyNames()) { Object property = source.getProperty(propertyName); if (textEncryptor != null){ property = "{cipher}" + textEncryptor.encrypt(String.valueOf(property)); } builder.append(propertyName).append("=").append(property).append("\n"); } LOGGER.info(">>>>>>>>>>>>>>>>> file content: {} <<<<<<<<<<<<<<<<<<<", builder); saveFile(builder.toString()); } /** * 保存配置到本地 * @param content 配置内容 */ private void saveFile(String content){ File file = new File(fallbackLocation + File.separator + ConfigServerBootStrap.FALLBACK_NAME); try { FileCopyUtils.copy(content.getBytes(), file); } catch (IOException e) { e.printStackTrace(); } } } // 用于判断从远程拉取配置文件，还是从本地拉取（spring boot 2.0，spring cloud F版） @Configuration @EnableConfigurationProperties @PropertySource(value = {"config-client.properties","file:{spring.cloud.config.fallback-location:}/fallback.properties"}, ignoreResourceNotFound = true) public class ConfigServerBootStrap { public static final String FALLBACK_NAME = "fallback.properties"; private final ConfigurableEnvironment configurableEnvironment; @Autowired public ConfigServerBootStrap(ConfigurableEnvironment configurableEnvironment) { this.configurableEnvironment = configurableEnvironment; } @Value("${spring.cloud.config.fallback-location:}") private String fallbackLocation; @Bean public ConfigClientProperties configClientProperties(){ ConfigClientProperties configClientProperties = new ConfigClientProperties(this.configurableEnvironment); configClientProperties.setEnabled(false); return configClientProperties; } @Bean public FallbackableConfigServerPropertySourceLocator fallbackableConfigServerPropertySourceLocator(){ ConfigClientProperties client = configClientProperties(); return new FallbackableConfigServerPropertySourceLocator(client, fallbackLocation); } }

在 SpringBoot 1.0、Spring Cloud G 版中，会启动报错：

*************************** APPLICATION FAILED TO START *************************** Description: The bean 'configClientProperties', defined in class path resource [com/laiyy/gitee/config/springcloudconfigfallbackautorefresh/ConfigServerBootStrap.class], could not be registered. A bean with that name has already been defined in class path resource [org/springframework/cloud/config/client/ConfigServiceBootstrapConfiguration.class] and overriding is disabled. Action: Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true 2019-03-07 10:10:11.230 ERROR 13828 --- [ main] o.s.boot.SpringApplication : Application run failed org.springframework.beans.factory.support.BeanDefinitionOverrideException: Invalid bean definition with name 'configClientProperties' defined in class path resource [com/laiyy/gitee/config/springcloudconfigfallbackautorefresh/ConfigServerBootStrap.class]: Cannot register bean definition [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=com.laiyy.gitee.config.springcloudconfigfallbackautorefresh.ConfigServerBootStrap; factoryMethodName=configClientProperties; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [com/laiyy/gitee/config/springcloudconfigfallbackautorefresh/ConfigServerBootStrap.class]] for bean 'configClientProperties': There is already [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.cloud.config.client.ConfigServiceBootstrapConfiguration; factoryMethodName=configClientProperties; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/cloud/config/client/ConfigServiceBootstrapConfiguration.class]] bound. at org.springframework.beans.factory.support.DefaultListableBeanFactory.registerBeanDefinition(DefaultListableBeanFactory.java:894) ~[spring-beans-5.1.2.RELEASE.jar:5.1.2.RELEASE] at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForBeanMethod(ConfigurationClassBeanDefinitionReader.java:274) ~[spring-context-5.1.2.RELEASE.jar:5.1.2.RELEASE] ....

如果按照报错提示，增加了 spring.main.allow-bean-definition-overriding=true 的配置，没有任何作用；如果修改了 bean 名称

@Bean(name="clientProperties") public ConfigClientProperties configClientProperties(){ ConfigClientProperties configClientProperties = new ConfigClientProperties(this.configurableEnvironment); configClientProperties.setEnabled(false); return configClientProperties; }

会有如下报错：

*************************** APPLICATION FAILED TO START *************************** Description: Method configClientProperties in org.springframework.cloud.config.client.ConfigClientAutoConfiguration required a single bean, but 2 were found: - configClientProperties: defined by method 'configClientProperties' in class path resource [org/springframework/cloud/config/client/ConfigClientAutoConfiguration.class] - clientProperties: defined by method 'configClientProperties' in class path resource [com/laiyy/gitee/config/springcloudconfigfallbackautorefresh/ConfigServerBootStrap.class] Action: Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed

原因：ConfigClientProperties 在初始化时已经默认单例加载。即：这个 bean 不能被重新注册到 spring 容器中。解决办法：将 spring 容器已经加载的单例的 ConfigClientProperties 注入进来，并在构造中设置为 false 即可

@Configuration @EnableConfigurationProperties @PropertySource(value = {"configClient.properties", "file:${spring.cloud.config.fallbackLocation:}/fallback.properties"}, ignoreResourceNotFound = true) public class ConfigServerBootStrap { public static final String FALLBACK_NAME = "fallback.properties"; private final ConfigurableEnvironment configurableEnvironment; private final ConfigClientProperties configClientProperties; @Autowired public ConfigServerBootStrap(ConfigurableEnvironment configurableEnvironment, ConfigClientProperties configClientProperties) { this.configurableEnvironment = configurableEnvironment; this.configClientProperties = configClientProperties; this.configClientProperties.setEnabled(false); } @Value("${spring.cloud.config.fallbackLocation:}") private String fallbackLocation; @Bean public FallbackableConfigServerPropertySourceLocator fallbackableConfigServerPropertySourceLocator() { return new FallbackableConfigServerPropertySourceLocator(configClientProperties, fallbackLocation); } }

config client

bootstrap.yml

spring: cloud: config: uri: http://localhost:9090 label: master name: config-simple profile: dev fallbackLocation: E:\\springcloud

application.yml

server: port: 9091 spring: application: name: spring-cloud-autoconfig-client main: allow-bean-definition-overriding: true management: endpoints: web: exposure: include: '*' endpoint: health: show-details: always

其余配置、JAVA 类不变

验证

启动 config client，查看控制台，可见打印了 2 次远程拉取同步本地文件的信息：

>>>>>>>>>>>>>>>>> file content: config.client.version=ee39bf20c492b27c2d1b1d0ff378ad721e79a758 com.laiyy.gitee.config=dev 环境，git 版 spring cloud config-----! <<<<<<<<<<<<<<<<<<<

查看本地 E:\springcloud 文件夹，可见多了一个 fallback.properties 文件

fallback local properties

文件内容：

fallback local properties content

更新 config repo 的对应配置文件后，POST 访问 config client 刷新端口：http://localhost:9091/actuator/refresh 可见控制台再次打印同步本地文件信息。此时停止 config server 访问，再次访问 http://localhost:9091/get-config-info ，返回的信息是同步后的更新结果，由此验证客户端回退成功。

作者：laiyy0728 链接：https://www.jianshu.com/p/ac6dda3115c6 来源：简书简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。

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