Spring Cloud 微服務公共配置處理

時間 2020-01-15

原文原文鏈接

Spring Cloud Config Server提供了微服務獲取配置的功能，這些配置文件（application.yml或者application.properties）一般維護在git或者數據庫中，並且支持經過RefreshScope動態刷新，使用起來仍是比較靈活的。可是當微服務愈來愈多時，會遇到下面幾個問題：mysql

配置文件的敏感數如數據庫地址和帳號信息，據呈如今每一個配置文件中，替換起來須要一個個配置文件進行修改。
各個微服務配置文件存在不少冗餘配置（如Eureka，Feign），一旦這些部分調整，須要針對每一個微服務進行調整，運維壓力大增。

爲了解決上述問題，咱們能夠從configServer服務着手進行改造，示意以下：
git

不一樣的服務ABC，無論是在配置中心倉庫端配置了多少個文件，從ConfigServer返回的，必定是服務最終應用的配置。獲取配置的方式，一般是調用ConfigServer的一個地址，如：redis

http://localhost:8021/common_rent/dev/aliyun_devspring

common_rent是application name，dev是profile，aliyun_dev是label（git的分支）。這個地址的處理接口，是ConfigServer的EnvironmentController，因此經過攔截這個接口，將敏感信息或者公共配置抽取到configServer的application.yml, 返回前進行替換或者拼接，便可實現上述目的。sql

代碼示例：mongodb

攔截器實現數據庫

@Component
@Aspect
public class ResourceLoaderInterceptor {

private static Log logger = LogFactory.getLog(ResourceLoaderInterceptor.class);
@Resource
ExternalProperties externalProperties;

@Around("execution(* org.springframework.cloud.config.server..*Controller.*(..)) ")
public Object commonPropertiesResolve(ProceedingJoinPoint joinPoint) throws Throwable {
    Object returnObj = null;
    Object[] args = joinPoint.getArgs();
    StopWatch stopWatch = new StopWatch();
    try {
        stopWatch.start();
        returnObj = joinPoint.proceed(args);
        if (Environment.class.isInstance(returnObj)) {
            Environment environment = (Environment) returnObj;
            if (environment.getPropertySources() != null && environment.getPropertySources().size() > 0) {
                for (PropertySource propertySource : environment.getPropertySources()) {
                    placeHolderResolve((Map<String, Object>) propertySource.getSource());
                }
            }
        }
    } catch (Throwable throwable) {
        logger.error(ExceptionUtils.getStackTrace(throwable));
    } finally {
        stopWatch.stop();
        System.out.println(stopWatch.getTotalTimeMillis());
    }
    return returnObj;

}

private void placeHolderResolve(Map<String, Object> source) {
    Map<String, Object> placeHolders = collectConfigSet();
    for (String key : source.keySet()) {
        Object value = source.get(key);
        Object valueAfterReplace = null;
        if (value != null) {
            if (String.class.isInstance(value) && ((String) value).contains("${ext.")) {
                String varExp = (String) value;
                for (String variable : placeHolders.keySet()) {
                    String vk = "${" + variable + "}";
                    if (varExp.contains(vk)) {
                        Object replaceValue = placeHolders.get(variable);
                        if (replaceValue != null) {
                            if (varExp.equalsIgnoreCase(vk)) {
                                valueAfterReplace = replaceValue;
                                break;
                            } else {
                                varExp = StringUtils.replace(varExp, vk, "" + replaceValue);
                                if (!varExp.contains("${")) {
                                    break;
                                }
                            }
                        } else {
                            logger.error("Property " + vk + " is not properly configured!");
                        }
                    }
                }
                if (valueAfterReplace != null) {
                    source.put(key, valueAfterReplace);
                } else if (varExp.contains("${")) {
                    logger.error("Property " + varExp + " is not properly configured!");
                } else {
                    source.put(key, varExp);
                }
            }
        }
    }
}

private Map<String, Object> collectConfigSet() {
    Map<String, Object> placeHolders = new HashMap<>();
    Field[] fields = ExternalProperties.class.getDeclaredFields();
    for (int i = 0; i < fields.length; i++) {
        try {
            Field propertiesField = fields[i];
            ResourcePrefix resourcePrefix = propertiesField.getAnnotation(ResourcePrefix.class);
            String prefix = resourcePrefix.value();
            ExtDataSource extDataSource = (ExtDataSource) BeanUtils.getPropertyDescriptor(ExternalProperties.class, propertiesField.getName()).getReadMethod().invoke(externalProperties);
            if (extDataSource != null) {
                Field[] fields2 = ExtDataSource.class.getDeclaredFields();
                for (Field datasourceField : fields2) {
                    try {
                        ResourcePrefix annotation = datasourceField.getAnnotation(ResourcePrefix.class);
                        String suffix = annotation.value();
                        Object sourceFieldValue = BeanUtils.getPropertyDescriptor(ExtDataSource.class, datasourceField.getName()).getReadMethod().invoke(extDataSource);
                        if (sourceFieldValue != null) {
                            placeHolders.put(prefix + "." + suffix, sourceFieldValue);
                        }
                    } catch (Exception e) {
                        logger.error(ExceptionUtils.getStackTrace(e));
                    }
                }
            }
        } catch (Exception e) {
            logger.error(ExceptionUtils.getStackTrace(e));
        }
    }
    return placeHolders;
}
}

ExternalProperites實現

@ConfigurationProperties(prefix = "external", ignoreUnknownFields = true)
public class ExternalProperties implements Serializable {

    @ResourcePrefix(value = "ext.spring.datasource")
    private ExtDataSource datasource;
    @ResourcePrefix(value = "ext.spring.data.mongodb")
    private ExtDataSource mongodb;
    @ResourcePrefix(value = "ext.spring.redis")
    private ExtDataSource redis;
    @ResourcePrefix(value = "ext.spring.rabbitmq")
    private ExtDataSource rabbitmq;

    public ExtDataSource getDatasource() {
        return datasource;
    }

    public void setDatasource(ExtDataSource datasource) {
        this.datasource = datasource;
    }

    public ExtDataSource getRabbitmq() {
        return rabbitmq;
    }

    public void setRabbitmq(ExtDataSource rabbitmq) {
        this.rabbitmq = rabbitmq;
    }

    public ExtDataSource getMongodb() {
        return mongodb;
    }

    public void setMongodb(ExtDataSource mongodb) {
        this.mongodb = mongodb;
    }

    public ExtDataSource getRedis() {
        return redis;
    }

    public void setRedis(ExtDataSource redis) {
        this.redis = redis;
    }
}

ExtDataSource實現app

public class ExtDataSource {
@ResourcePrefix(value = "host")
private String host;
@ResourcePrefix(value = "port")
private Integer port;
@ResourcePrefix(value = "url")
private String url;
@ResourcePrefix(value = "uri")
private String uri;
@ResourcePrefix(value = "username")
private String userName;
@ResourcePrefix(value = "password")
private String password;

public String getUrl() {
    return url;
}

public void setUrl(String url) {
    this.url = url;
}

public String getHost() {
    return host;
}

public void setHost(String host) {
    this.host = host;
}

public Integer getPort() {
    return port;
}

public void setPort(Integer port) {
    this.port = port;
}

public String getUri() {
    return uri;
}

public void setUri(String uri) {
    this.uri = uri;
}

public String getUserName() {
    return userName;
}

public void setUserName(String userName) {
    this.userName = userName;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}
}

ResourcePrefix實現

@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface ResourcePrefix {
String value();
}

而後在configServer的application.yml中增長相關信息，如運維

external:
  datasource:
    host: 122.122.111.111
    port: 3307
    userName: usr
    password: pwd
  mongodb:
    host: 122.122.111.111
    port: 20467
    uri: 122.122.111.111:20467,122.122.111.112:20467,122.122.111.112:20467
    userName: usr
    password:  pwd
  redis:
    uri: 122.122.111.113:6379,122.122.112.113:6379,122.122.111.113:6379
    password: redispassword
  rabbitmq:
    host: 122.122.111.113
    port: 20467
    userName: usr
    password: pwd

將ServiceA的配置文件serviceA_dev.yml中的數據庫相關信息替換成變量，以mysql爲例
spring.datasource.uri: url: jdbc:mysql://#{ext.spring.datasource.host}:#{ext.spring.datasource.port}/dbName?useUnicode=true&characterEncoding=utf8,
serviceB和serviceC配置文件作一樣處理，便可實現一次性替換。ide

後續若是須要增長公共配置，能夠直接在ConfigServer的配置中間中增長，調整下攔截器的實現邏輯便可。