SpringCloud Gateway 请求响应日志

傷城~ 2022-10-14 12:50 329阅读 0赞

请求响应日志是日常开发调试定位问题的重要手段，在微服务中引入SpringCloud Gateway后我们希望在网关层统一进行日志的收集。

本节内容将实现以下两个功能：

获取请求的输入输出参数，封装成自定义日志  
将日志发送到MongoDB进行存储  
获取输入输出参数  
首先我们先定义一个日志体  
@Data  
public class GatewayLog \{  
/\**访问实例*/  
private String targetServer;  
/\**请求路径*/  
private String requestPath;  
/\**请求方法*/  
private String requestMethod;  
/\*\*协议 \*/  
private String schema;  
/\**请求体*/  
private String requestBody;  
/\**响应体*/  
private String responseData;  
/\**请求ip*/  
private String ip;  
/\**请求时间*/  
private Date requestTime;  
/*响应时间/  
private Date responseTime;  
/执行时间/  
private long executeTime;  
\}  
【关键】在网关定义日志过滤器，获取输入输出参数  
/*

*  日志过滤器，用于记录日志
 *  @author
 *  @date  
    \*/  
    @Slf4j  
    @Component  
    public class AccessLogFilter implements GlobalFilter, Ordered \{  
    @Autowired  
    private AccessLogService accessLogService;
    
    private final List<HttpMessageReader<?>> messageReaders = HandlerStrategies.withDefaults().messageReaders();
    
    @Override  
    public int getOrder() \{  
    return -100;  
    \}
    
    @Override  
    @SuppressWarnings(“unchecked”)  
    public Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) \{
    
        ServerHttpRequest request = exchange.getRequest();
        
         // 请求路径
         String requestPath = request.getPath().pathWithinApplication().value();
        
         Route route = getGatewayRoute(exchange);
        
        
         String ipAddress = WebUtils.getServerHttpRequestIpAddress(request);
        
         GatewayLog gatewayLog = new GatewayLog();
         gatewayLog.setSchema(request.getURI().getScheme());
         gatewayLog.setRequestMethod(request.getMethodValue());
         gatewayLog.setRequestPath(requestPath);
         gatewayLog.setTargetServer(route.getId());
         gatewayLog.setRequestTime(new Date());
         gatewayLog.setIp(ipAddress);
        
         MediaType mediaType = request.getHeaders().getContentType();
        
         if(MediaType.APPLICATION_FORM_URLENCODED.isCompatibleWith(mediaType) || MediaType.APPLICATION_JSON.isCompatibleWith(mediaType)){
             return writeBodyLog(exchange, chain, gatewayLog);
         }else{
             return writeBasicLog(exchange, chain, gatewayLog);
         }
    
    \}
    
    private Mono writeBasicLog(ServerWebExchange exchange, GatewayFilterChain chain, GatewayLog accessLog) \{  
    StringBuilder builder = new StringBuilder();  
    MultiValueMap<String, String> queryParams = exchange.getRequest().getQueryParams();  
    for (Map.Entry<String, List> entry : queryParams.entrySet()) \{  
    builder.append(entry.getKey()).append("=").append(StringUtils.join(entry.getValue(), “,”));  
    \}  
    accessLog.setRequestBody(builder.toString());
    
        //获取响应体
         ServerHttpResponseDecorator decoratedResponse = recordResponseLog(exchange, accessLog);
        
         return chain.filter(exchange.mutate().response(decoratedResponse).build())
                 .then(Mono.fromRunnable(() -> {
                     // 打印日志
                     writeAccessLog(accessLog);
                 }));
    
    \}
    
    /\*\*
    
     *  解决 request body 只能读取一次问题，
     *  参考: org.springframework.cloud.gateway.filter.factory.rewrite.ModifyRequestBodyGatewayFilterFactory
     *  @param exchange
     *  @param chain
     *  @param gatewayLog
     *  @return  
        \*/  
        @SuppressWarnings(“unchecked”)  
        private Mono writeBodyLog(ServerWebExchange exchange, GatewayFilterChain chain, GatewayLog gatewayLog) \{  
        ServerRequest serverRequest = ServerRequest.create(exchange,messageReaders);
        
        Mono modifiedBody = serverRequest.bodyToMono(String.class)  
        .flatMap(body ->\{  
        gatewayLog.setRequestBody(body);  
        return Mono.just(body);  
        \});
        
        // 通过 BodyInserter 插入 body(支持修改body), 避免 request body 只能获取一次  
        BodyInserter bodyInserter = BodyInserters.fromPublisher(modifiedBody, String.class);  
        HttpHeaders headers = new HttpHeaders();  
        headers.putAll(exchange.getRequest().getHeaders());  
        // the new content type will be computed by bodyInserter  
        // and then set in the request decorator  
        headers.remove(HttpHeaders.CONTENT\_LENGTH);
        
        CachedBodyOutputMessage outputMessage = new CachedBodyOutputMessage(exchange, headers);
        
        return bodyInserter.insert(outputMessage,new BodyInserterContext())  
        .then(Mono.defer(() -> \{  
        // 重新封装请求  
        ServerHttpRequest decoratedRequest = requestDecorate(exchange, headers, outputMessage);
        
            // 记录响应日志
                     ServerHttpResponseDecorator decoratedResponse = recordResponseLog(exchange, gatewayLog);
            
                     // 记录普通的
                     return chain.filter(exchange.mutate().request(decoratedRequest).response(decoratedResponse).build())
                             .then(Mono.fromRunnable(() -> {
                                 // 打印日志
                                 writeAccessLog(gatewayLog);
                             }));
                 }));
    
    \}
    
    /\*\*
    
     *  打印日志
     *  @author
     *  @date
     *  @param gatewayLog 网关日志  
        \*/  
        private void writeAccessLog(GatewayLog gatewayLog) \{  
        log.info(gatewayLog.toString());  
        \}
    
    private Route getGatewayRoute(ServerWebExchange exchange) \{  
    return exchange.getAttribute(ServerWebExchangeUtils.GATEWAY\_ROUTE\_ATTR);  
    \}
    
    /\*\*
    
     *  请求装饰器，重新计算 headers
     *  @param exchange
     *  @param headers
     *  @param outputMessage
     *  @return  
        \*/  
        private ServerHttpRequestDecorator requestDecorate(ServerWebExchange exchange, HttpHeaders headers,  
        CachedBodyOutputMessage outputMessage) \{  
        return new ServerHttpRequestDecorator(exchange.getRequest()) \{  
        @Override  
        public HttpHeaders getHeaders() \{  
        long contentLength = headers.getContentLength();  
        HttpHeaders httpHeaders = new HttpHeaders();  
        httpHeaders.putAll(super.getHeaders());  
        if (contentLength > 0) \{  
        httpHeaders.setContentLength(contentLength);  
        \} else \{  
        // TODO: this causes a ‘HTTP/1.1 411 Length Required’ // on  
        // httpbin.org  
        httpHeaders.set(HttpHeaders.TRANSFER\_ENCODING, “chunked”);  
        \}  
        return httpHeaders;  
        \}
        
            @Override
             public Flux<DataBuffer> getBody() {
                 return outputMessage.getBody();
             }
        
        \};  
        \}
    
    /\*\*
    
     *  记录响应日志
     *  通过 DataBufferFactory 解决响应体分段传输问题。  
        \*/  
        private ServerHttpResponseDecorator recordResponseLog(ServerWebExchange exchange, GatewayLog gatewayLog) \{  
        ServerHttpResponse response = exchange.getResponse();  
        DataBufferFactory bufferFactory = response.bufferFactory();
        
        return new ServerHttpResponseDecorator(response) \{  
        @Override  
        public Mono writeWith(Publisher<? extends DataBuffer> body) \{  
        if (body instanceof Flux) \{  
        Date responseTime = new Date();  
        gatewayLog.setResponseTime(responseTime);  
        // 计算执行时间  
        long executeTime = (responseTime.getTime() - gatewayLog.getRequestTime().getTime());
        
            gatewayLog.setExecuteTime(executeTime);
            
                     // 获取响应类型，如果是 json 就打印
                     String originalResponseContentType = exchange.getAttribute(ServerWebExchangeUtils.ORIGINAL_RESPONSE_CONTENT_TYPE_ATTR);
            
            
                     if (ObjectUtil.equal(this.getStatusCode(), HttpStatus.OK)
                             && StringUtil.isNotBlank(originalResponseContentType)
                             && originalResponseContentType.contains("application/json")) {
            
                         Flux<? extends DataBuffer> fluxBody = Flux.from(body);
                         return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
            
                             // 合并多个流集合，解决返回体分段传输
                             DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
                             DataBuffer join = dataBufferFactory.join(dataBuffers);
                             byte[] content = new byte[join.readableByteCount()];
                             join.read(content);
            
                             // 释放掉内存
                             DataBufferUtils.release(join);
                             String responseResult = new String(content, StandardCharsets.UTF_8);
            
            
            
                             gatewayLog.setResponseData(responseResult);
            
                             return bufferFactory.wrap(content);
                         }));
                     }
                 }
                 // if body is not a flux. never got there.
                 return super.writeWith(body);
             }
        
        \};  
        \}  
        \}  
        代码较长建议直接拷贝到编辑器，只要注意下面一个关键点：

getOrder()方法返回的值必须要<-1，「否则标准的NettyWriteResponseFilter将在您的过滤器被调用的机会之前发送响应，即不会执行获取后端响应参数的方法」

通过上面的两步我们已经可以获取到请求的输入输出参数了，在 writeAccessLog()中将其输出到了日志文件，大家可以在Postman发送请求观察日志。

存储日志  
如果需要将日志持久化方便后期检索的话可以考虑将日志存储在MongoDB中，实现过程很简单。（安装MongoDB可以参考这篇文章：实战|MongoDB的安装配置）

引入MongoDB  
  
org.springframework.boot  
spring-boot-starter-data-mongodb-reactive  
  
由于gateway是基于webflux，所以我们需要选择reactive版本。

在GatewayLog上添加对应的注解  
@Data  
@Document  
public class GatewayLog \{  
@Id  
private String id;  
…  
\}  
建立AccessLogRepository  
@Repository  
public interface AccessLogRepository extends ReactiveMongoRepository<GatewayLog,String> \{

\}  
建立Service  
public interface AccessLogService \{

/**
     * 保存AccessLog
     * @param gatewayLog 请求响应日志
     * @return 响应日志
     */
    Mono<GatewayLog> saveAccessLog(GatewayLog gatewayLog);

\}  
建立实现类  
@Service  
public class AccessLogServiceImpl implements AccessLogService \{  
@Autowired  
private AccessLogRepository accessLogRepository;

@Override
    public Mono<GatewayLog> saveAccessLog(GatewayLog gatewayLog) {
        return accessLogRepository.insert(gatewayLog);
    }

\}  
在Nacos配置中心添加MongoDB对应配置  
spring:  
data:  
mongodb:  
host: xxx.xx.x.xx  
port: 27017  
database: accesslog  
username: accesslog  
password: xxxxxx  
执行请求，打开MongoDB客户端，查看日志结果