SpringCloud：搭建基于Gateway的微服务网关（二）

0.代码

1.引入相关依赖

pom文件如下：

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <parent>

        <artifactId>OpenAPI</artifactId>

        <groupId>com.fdzang.microservice</groupId>

        <version>1.0-SNAPSHOT</version>

    </parent>

    <modelVersion>4.0.0</modelVersion>

    <artifactId>api-gateway</artifactId>

    <dependencies>
　　　　 <!-- 公共模块引入了web模块，会与gateway产生冲突，故排除 -->

        <dependency>

            <groupId>com.fdzang.microservice</groupId>

            <artifactId>api-common</artifactId>

            <version>1.0-SNAPSHOT</version>

            <exclusions>

                <exclusion>

                    <groupId>org.springframework.boot</groupId>

                    <artifactId>spring-boot-starter-web</artifactId>

                </exclusion>

            </exclusions>

        </dependency>

        <dependency>

            <groupId>org.projectlombok</groupId>

            <artifactId>lombok</artifactId>

        </dependency>

        <dependency>

            <groupId>org.apache.commons</groupId>

            <artifactId>commons-collections4</artifactId>

        </dependency>

        <dependency>

            <groupId>commons-io</groupId>

            <artifactId>commons-io</artifactId>

        </dependency>

        <dependency>

            <groupId>commons-codec</groupId>

            <artifactId>commons-codec</artifactId>

        </dependency>

        <dependency>

            <groupId>com.google.guava</groupId>

            <artifactId>guava</artifactId>

        </dependency>

        <dependency>

            <groupId>com.google.code.gson</groupId>

            <artifactId>gson</artifactId>

        </dependency>

        <dependency>

            <groupId>com.alibaba</groupId>

            <artifactId>fastjson</artifactId>

            <version>${fastjson.version}</version>

        </dependency>

　　　　 <!-- 引入gateway模块 -->　　　　

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-gateway</artifactId>

            <version>${spring.cloud.starter.version}</version>

        </dependency>


　　　　 <!-- 引入eureka模块 -->

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>

            <version>${spring.cloud.starter.version}</version>

        </dependency>


　　　　　<!-- 引入openfeign模块,这里不要用feign，Springboot2.0已弃用 -->

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-openfeign</artifactId>

            <version>${spring.cloud.starter.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>

            <version>${spring.cloud.starter.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-configuration-processor</artifactId>

            <version>${spring.boot.version}</version>

            <optional>true</optional>

        </dependency>

    </dependencies>

</project>

2.配置Gateway

server:

  port: 7000


#注册到eureka

eureka:

  client:

    service-url:

      defaultZone: http://127.0.0.1:7003/eureka/


#配置gateway拦截规则

spring:

  application:

    name: api-gateway

  cloud:

    gateway:

      discovery:

        locator:

          enabled: true

      routes:

        - id: gateway

          uri: http://www.baidu.com

          predicates:

            - Path=/**


#这里定义了鉴权的服务名，以及白名单

auth:

  service-id: api-auth-v1

  gateway:

    white:

      - /login

#这里是id生成器的配置，Twitter-Snowflake

IdWorker:

  workerId: 122

  datacenterId: 1231

3.过滤器

3.1.ID生成拦截

对每个请求生成一个唯一的请求id

package com.fdzang.microservice.gateway.gateway;

import com.fdzang.microservice.gateway.util.GatewayConstant;

import com.fdzang.microservice.gateway.util.IdWorker;

import lombok.extern.slf4j.Slf4j;

import org.apache.commons.lang.StringUtils;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;

import org.springframework.cloud.gateway.filter.GlobalFilter;

import org.springframework.core.Ordered;

import org.springframework.http.server.reactive.ServerHttpRequest;

import org.springframework.stereotype.Component;

import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Mono;

/**

 * 生成一个请求的特定id

 * @author tanghu

 * @Date: 2019/11/5 18:42

 */

@Slf4j

@Component

public class SerialNoFilter implements GlobalFilter, Ordered {

    @Override

    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        ServerHttpRequest request = exchange.getRequest();

        String requestId= request.getHeaders().getFirst(GatewayConstant.REQUEST_TRACE_ID);

        if (StringUtils.isEmpty(requestId)) {

            Object attribute = exchange.getAttribute(GatewayConstant.REQUEST_TRACE_ID);

            if (attribute == null) {

                requestId = String.valueOf(IdWorker.getWorkerId());

                exchange.getAttributes().put(GatewayConstant.REQUEST_TRACE_ID,requestId);

            }

        }else{

            exchange.getAttributes().put(GatewayConstant.REQUEST_TRACE_ID,requestId);

        }

        return chain.filter(exchange);

    }

    @Override

    public int getOrder() {

        return GatewayConstant.Order.SERIAL_NO_ORDER;

    }

}

3.2.鉴权拦截

获取请求头中的鉴权信息，对信息校验，这里暂时没有做（AuthResult authService.auth(AuthRequest request)）,这里需求请求其他模块对请求信息进行校验，返回校验结果

package com.fdzang.microservice.gateway.gateway;

import com.fdzang.microservice.common.entity.auth.AuthCode;

import com.fdzang.microservice.common.entity.auth.AuthRequest;

import com.fdzang.microservice.common.entity.auth.AuthResult;

import com.fdzang.microservice.gateway.service.AuthService;

import com.fdzang.microservice.gateway.util.GatewayConstant;

import com.fdzang.microservice.gateway.util.WhiteUrl;

import com.google.common.base.Joiner;

import com.google.common.base.Splitter;

import lombok.extern.slf4j.Slf4j;

import org.apache.commons.collections4.MapUtils;

import org.apache.commons.lang.StringUtils;

import org.apache.commons.lang.math.NumberUtils;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;

import org.springframework.cloud.gateway.filter.GlobalFilter;

import org.springframework.core.Ordered;

import org.springframework.http.HttpHeaders;

import org.springframework.http.server.reactive.ServerHttpRequest;

import org.springframework.stereotype.Component;

import org.springframework.util.CollectionUtils;

import org.springframework.util.MultiValueMap;

import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Mono;

import java.util.List;

import java.util.Map;

import java.util.TreeMap;

/**

 * 权限校验

 * @author tanghu

 * @Date: 2019/10/22 18:00

 */

@Slf4j

@Component

public class AuthFilter implements GlobalFilter, Ordered {

    @Autowired

    private AuthService authService;

    @Override

    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        String requestId = exchange.getAttribute(GatewayConstant.REQUEST_TRACE_ID);

        String url = exchange.getRequest().getURI().getPath();

        ServerHttpRequest request = exchange.getRequest();

        //跳过白名单

        if(null != WhiteUrl.getWhite() && WhiteUrl.getWhite().contains(url)){

            return chain.filter(exchange);

        }

        //获取权限校验部分

        //Authorization: gateway:{AccessId}:{Signature}

        String authHeader = exchange.getRequest().getHeaders().getFirst(GatewayConstant.AUTH_HEADER);

        if(StringUtils.isBlank(authHeader)){

            log.warn("request has no authorization header, uuid:{}, request:{}",requestId, url);

            throw new IllegalArgumentException("bad request");

        }

        List<String> auths = Splitter.on(":").trimResults().omitEmptyStrings().splitToList(authHeader);

        if(CollectionUtils.isEmpty(auths) || auths.size() != 3 || !GatewayConstant.AUTH_LABLE.equals(auths.get(0))){

            log.warn("bad authorization header, uuid:{}, request:[{}], header:{}",

                    requestId, url, authHeader);

            throw new IllegalArgumentException("bad request");

        }

        //校验时间戳是否合法

        String timestamp = exchange.getRequest().getHeaders().getFirst(GatewayConstant.TIMESTAMP_HEADER);

        if (StringUtils.isBlank(timestamp) || isTimestampExpired(timestamp)) {

            log.warn("wrong timestamp:{}, uuid:{}, request:{}",

                    timestamp, requestId, url);

        }

        String accessId = auths.get(1);

        String sign = auths.get(2);

        String stringToSign = getStringToSign(request, timestamp);

        AuthRequest authRequest = new AuthRequest();

        authRequest.setAccessId(accessId);

        authRequest.setSign(sign);

        authRequest.setStringToSign(stringToSign);

        authRequest.setHttpMethod(request.getMethodValue());

        authRequest.setUri(url);

        AuthResult authResult = authService.auth(authRequest);

        if (authResult.getStatus() != AuthCode.SUCEESS.getAuthCode()) {

            log.warn("checkSign failed, uuid:{},  accessId:{}, request:[{}], error:{}",

                    requestId, accessId, url, authResult.getDescription());

            throw new RuntimeException(authResult.getDescription());

        }

        log.info("request auth finished, uuid:{}, orgCode:{}, userName:{}, accessId:{}, request:{}, serviceName:{}",

                requestId, authResult.getOrgCode(),

                authResult.getUsername(), accessId,

                url, authResult.getServiceName());

        exchange.getAttributes().put(GatewayConstant.SERVICE_NAME,authResult.getServiceName());

        return chain.filter(exchange);

    }

    /**

     * 获取原始字符串（签名前）

     * @param request

     * @param timestamp

     * @return

     */

    private String getStringToSign(ServerHttpRequest request, String timestamp){

        // headers

        TreeMap<String, String> headersInSign = new TreeMap<>();

        HttpHeaders headers = request.getHeaders();

        for (Map.Entry<String,List<String>> header:headers.entrySet()) {

            String key = header.getKey();

            if (key.startsWith(GatewayConstant.AUTH_HEADER_PREFIX)) {

                headersInSign.put(key, header.getValue().get(0));

            }

        }

        StringBuilder headerStringBuilder = new StringBuilder();

        for (Map.Entry<String, String> entry : headersInSign.entrySet()) {

            headerStringBuilder.append(entry.getKey()).append(":").append(entry.getValue()).append("\n");

        }

        String headerString = null;

        if (headerStringBuilder.length() != 0) {

            headerString = headerStringBuilder.deleteCharAt(headerStringBuilder.length()-1).toString();

        }

        // Url_String

        TreeMap<String, String> paramsInSign = new TreeMap<>();

        MultiValueMap<String, String> parameterMap = request.getQueryParams();

        if (MapUtils.isNotEmpty(parameterMap)) {

            for (Map.Entry<String, List<String>> entry : parameterMap.entrySet()) {

                paramsInSign.put(entry.getKey(), entry.getValue().get(0));

            }

        }

        // 原始url

        String originalUrl = request.getURI().getPath();

        StringBuilder uriStringBuilder = new StringBuilder(originalUrl);

        if (!parameterMap.isEmpty()) {

            uriStringBuilder.append("?");

            for (Map.Entry<String, String> entry : paramsInSign.entrySet()) {

                uriStringBuilder.append(entry.getKey());

                if (StringUtils.isNotBlank(entry.getValue())) {

                    uriStringBuilder.append("=").append(entry.getValue());

                }

                uriStringBuilder.append("&");

            }

            uriStringBuilder.deleteCharAt(uriStringBuilder.length()-1);

        }

        String uriString = uriStringBuilder.toString();

        String contentType = headers.getFirst(HttpHeaders.CONTENT_TYPE);

        //这里可以对请求参数进行MD5校验，暂时不做

        String contentMd5 = headers.getFirst(GatewayConstant.CONTENTE_MD5);

        String[] parts = {

                request.getMethodValue(),

                StringUtils.isNotBlank(contentMd5) ? contentMd5 : "",

                StringUtils.isNotBlank(contentType) ? contentType : "",

                timestamp,

                headerString,

                uriString

        };

        return Joiner.on(GatewayConstant.STRING_TO_SIGN_DELIM).skipNulls().join(parts);

    }

    /**

     * 校验时间戳是否超时

     * @param timestamp

     * @return

     */

    private boolean isTimestampExpired(String timestamp){

        long l = NumberUtils.toLong(timestamp, 0L);

        if (l == 0) {

            return true;

        }

        return Math.abs(System.currentTimeMillis() - l) > GatewayConstant.EXPIRE_TIME_SECONDS *1000;

    }

    @Override

    public int getOrder() {

        return GatewayConstant.Order.AUTH_ORDER;

    }

}

3.3.服务分发

根据鉴权后的结果能得到服务名，然后重写路由以及请求，对该次请求进行转发

package com.fdzang.microservice.gateway.gateway;

import com.fdzang.microservice.gateway.util.GatewayConstant;

import com.fdzang.microservice.gateway.util.WhiteUrl;

import com.google.common.base.Splitter;

import lombok.extern.slf4j.Slf4j;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;

import org.springframework.cloud.gateway.filter.GlobalFilter;

import org.springframework.cloud.gateway.route.Route;

import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;

import org.springframework.core.Ordered;

import org.springframework.http.server.reactive.ServerHttpRequest;

import org.springframework.stereotype.Component;

import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Mono;

import java.util.List;

/**

 * @author tanghu

 * @Date: 2019/11/6 15:39

 */

@Slf4j

@Component

public class ModifyRequestFilter implements GlobalFilter, Ordered {

    @Override

    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        String url = exchange.getRequest().getURI().getPath();

        ServerHttpRequest request = exchange.getRequest();

        //跳过白名单

        if(null != WhiteUrl.getWhite() && WhiteUrl.getWhite().contains(url)){

            return chain.filter(exchange);

        }

        String serviceName = exchange.getAttribute(GatewayConstant.SERVICE_NAME);

        //修改路由

        Route route = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);

        Route newRoute = Route.async()

                .asyncPredicate(route.getPredicate())

                .filters(route.getFilters())

                .id(route.getId())

                .order(route.getOrder())

                .uri(GatewayConstant.URI.LOAD_BALANCE+serviceName).build();

        exchange.getAttributes().put(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR,newRoute);

        //修改请求路径

        List<String> strings = Splitter.on("/").omitEmptyStrings().trimResults().limit(3).splitToList(url);

        String newServletPath = "/" + strings.get(2);

        ServerHttpRequest newRequest = request.mutate().path(newServletPath).build();

        return chain.filter(exchange.mutate().request(newRequest).build());

    }

    @Override

    public int getOrder() {

        return GatewayConstant.Order.MODIFY_REQUEST_ORDER;

    }

}

3.4.统一响应

对响应进行统一封装

package com.fdzang.microservice.gateway.gateway;

import com.alibaba.fastjson.JSON;

import com.fdzang.microservice.common.entity.ApiResult;

import com.fdzang.microservice.gateway.entity.GatewayError;

import com.fdzang.microservice.gateway.entity.GatewayResult;

import com.fdzang.microservice.gateway.entity.GatewayResultEnums;

import com.fdzang.microservice.gateway.util.GatewayConstant;

import lombok.extern.slf4j.Slf4j;

import org.reactivestreams.Publisher;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;

import org.springframework.cloud.gateway.filter.GlobalFilter;

import org.springframework.cloud.gateway.filter.NettyWriteResponseFilter;

import org.springframework.core.Ordered;

import org.springframework.core.io.buffer.DataBuffer;

import org.springframework.core.io.buffer.DataBufferFactory;

import org.springframework.core.io.buffer.DataBufferUtils;

import org.springframework.http.server.reactive.ServerHttpResponse;

import org.springframework.http.server.reactive.ServerHttpResponseDecorator;

import org.springframework.stereotype.Component;

import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.nio.charset.Charset;

/**

 * @author tanghu

 * @Date: 2019/11/7 8:58

 */

@Slf4j

@Component

public class ModifyResponseFilter implements GlobalFilter, Ordered {

    @Override

    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        String requestId = exchange.getAttribute(GatewayConstant.REQUEST_TRACE_ID);

        ServerHttpResponse originalResponse = exchange.getResponse();

        DataBufferFactory bufferFactory = originalResponse.bufferFactory();

        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {

            @Override

            public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {

                if (body instanceof Flux) {

                    Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>) body;

                    return super.writeWith(fluxBody.map(dataBuffer -> {

                        byte[] content = new byte[dataBuffer.readableByteCount()];

                        dataBuffer.read(content);

                        //释放掉内存

                        DataBufferUtils.release(dataBuffer);

                        String originalbody = new String(content, Charset.forName("UTF-8"));

                        String finalBody = originalbody;

                        ApiResult apiResult = JSON.parseObject(originalbody,ApiResult.class);

                        GatewayResult result = new GatewayResult();

                        result.setCode(GatewayResultEnums.SUCC.getCode());

                        result.setMsg(GatewayResultEnums.SUCC.getMsg());

                        result.setReq_id(requestId);

                        if (apiResult.getCode() == null && apiResult.getMsg() == null) {

                            // 尝试解析body为网关的错误信息

                            GatewayError gatewayError = JSON.parseObject(originalbody,GatewayError.class);

                            result.setSub_code(gatewayError.getStatus());

                            result.setSub_msg(gatewayError.getMessage());

                        } else {

                            result.setSub_code(apiResult.getCode());

                            result.setSub_msg(apiResult.getMsg());

                        }

                        result.setData(apiResult.getData());

                        finalBody = JSON.toJSONString(result);

                        return bufferFactory.wrap(finalBody.getBytes());

                    }));

                }

                return super.writeWith(body);

            }

        };

        return chain.filter(exchange.mutate().response(decoratedResponse).build());

    }

    @Override

    public int getOrder() {

        return GatewayConstant.Order.MODIFY_RESPONSE_ORDER;

    }

}

4.测试

10:25:54.961 [main] INFO  c.f.microservice.mock.util.SignUtil - StringToSign:

GET

1573093554201

/v2/base/zuul/tag/getMostUsedTags?from=2017-11-25 00:00:00&plate_num=部A11110&to=2017-11-30 00:00:00

10:25:54.979 [main] INFO  c.f.microservice.mock.util.HttpUtil - sign:Y+usbpHlwOw4F2sq4b0pNjgXGDAXoYgs1syOOPxPFAE=

10:25:59.868 [main] INFO  com.fdzang.microservice.mock.Demo - {"code":0,"data":[{"tagPublishedRefCount":3,"tagTitle":"Solo","id":"1533101769023","tagReferenceCount":3},{"tagPublishedRefCount":1,"tagTitle":"tetet","id":"1559285894006","tagReferenceCount":1}],"msg":"succ","req_id":"2627469547766022144","sub_code":0,"sub_msg":"ok"}

Process finished with exit code 0

由返回结果，可知此次请求完成。

5.注意事项

转发的目标服务需要跟网关注册在同一个注册中心下，路由uri配置为 lb://service_name，则会转发到对应的服务下，并且gateway会自动采用负载均衡机制

响应请求的顺序需要小于 NettyWriteResponseFilter.WRITE_RESPONSE_FILTER_ORDER 该值为-1

其他拦截器的顺序无固定要求，值越小越先执行

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