gRPC 中打印请求二进制日志

r囧r小猫 2022-10-22 02:58 117阅读 0赞

# gRPC 中打印请求二进制日志 #

gRPC 支持将请求调用的参数、Header 等信息以二进制的方式输出到文件中，方便在必要时排查问题

## 使用 ##

#### 1. 添加依赖 ####

binlog 的依赖在 `grpc-services`中，所以需要有该依赖

dependencies { 
        implementation("io.grpc:grpc-services:${ grpcVersion}")
    }

#### 2. 添加 BinaryLogSink 实现 ####

@Slf4j
    public class CustomBinaryLogSink implements BinaryLogSink { 
    
        private final String outPath;
        private final OutputStream out;
        private boolean closed;
    
        CustomBinaryLogSink(String path) throws IOException { 
            File outFile = new File(path);
            outPath = outFile.getAbsolutePath();
            log.info("Writing binary logs to {}", outFile.getAbsolutePath());
            out = new BufferedOutputStream(new FileOutputStream(outFile));
        }
    
        String getPath() { 
            return this.outPath;
        }
    
        @Override
        public synchronized void write(MessageLite message) { 
            if (closed) { 
                log.info("Attempt to write after TempFileSink is closed.");
                return;
            }
            try { 
                message.writeDelimitedTo(out);
                out.flush();
            } catch (IOException e) { 
                log.info("Caught exception while writing", e);
                closeQuietly();
            }
        }
    
        @Override
        public synchronized void close() throws IOException { 
            if (closed) { 
                return;
            }
            closed = true;
            try { 
                out.flush();
            } finally { 
                out.close();
            }
        }
    
        private synchronized void closeQuietly() { 
            try { 
                close();
            } catch (IOException e) { 
                log.info("Caught exception while closing", e);
            }
        }
    }

#### 3. 创建 Channel 时指定 BinaryLog ####

BinaryLog binaryLog = BinaryLogs.createBinaryLog(new CustomBinaryLogSink("CUSTOM_PATH"), "*");
    this.channel = ManagedChannelBuilder.forAddress(host, port)
                                        .usePlaintext()
                                        .setBinaryLog(binaryLog)
                                        .build();

#### 4. 指定环境变量 ####

需要指定环境变量，设置需要输出的方法才会生效，设置 `GRPC_BINARY_LOG_CONFIG=*`，`*`代表打印所有的方法，具体指定可以参考 [Control Interface][]

然后就会将请求的 header、message 等内容以二进制输出到文件中，如：

]
    
    �������� (2E
    1/io.github.helloworlde.grpc.HelloService/SayHello127.0.0.1:9090$

#### 5. 修改输出内容 ####

二进制文件无法直接读取，依赖读取之后再将其输出为其他格式才可以，可以在写入时从 `MessageLite` 读取内容，修改为想要输出的格式

public synchronized void write(MessageLite message) {
            if (closed) {
                log.info("Attempt to write after TempFileSink is closed.");
                return;
            }
            try {
    -           // message.writeDelimitedTo(out);
    
    +            out.write(message.toString().getBytes(StandardCharsets.UTF_8));
                out.flush();
            } catch (IOException e) {
                log.info("Caught exception while writing", e);
                closeQuietly();
            }
        }

这样，就会将 `MessageLite` 的内容直接转为 String 后输出：

timestamp {
      seconds: 1609735898
      nanos: 879000000
    }
    call_id: 1
    sequence_id_within_call: 5
    type: EVENT_TYPE_SERVER_MESSAGE
    logger: LOGGER_CLIENT
    message {
      length: 14
      data: "\n\fHello Binlog"
    }
    
    timestamp {
      seconds: 1609735898
      nanos: 882000000
    }
    call_id: 1
    sequence_id_within_call: 6
    type: EVENT_TYPE_SERVER_TRAILER
    logger: LOGGER_CLIENT
    trailer {
      metadata {
      }
    }

## 实现原理 ##

在方法调用时，会判断有没有设置 binlog 对象，如果有则会封装方法，添加处理器和监听器；然后重新创建 `ServerMethodDefinition`；通过二进制日志拦截器 `io.grpc.services.BinlogHelper#getClientInterceptor` 拦截请求并写入日志

*  io.grpc.internal.ServerImpl.ServerTransportListenerImpl\#startCall

private <ReqT, RespT> ServerStreamListener startCall(ServerStream stream, String fullMethodName,
            ServerMethodDefinition<ReqT, RespT> methodDef, Metadata headers,
            Context.CancellableContext context, StatsTraceContext statsTraceCtx, Tag tag) { 
    
          // 如果 binlog 不为空，即需要记录binlog，则添加请求监听器和方法处理器记录 binlog
          ServerMethodDefinition<?, ?> wMethodDef = binlog == null ? interceptedDef : binlog.wrapMethodDefinition(interceptedDef);
    
          return startWrappedCall(fullMethodName, wMethodDef, stream, headers, context, tag);
        }

*  io.grpc.services.BinaryLogProvider\#wrapMethodDefinition

public final <ReqT, RespT> ServerMethodDefinition<?, ?> wrapMethodDefinition(ServerMethodDefinition<ReqT, RespT> oMethodDef) { 
        // 根据方法获取二进制日志拦截器，如果没有该方法则不拦截
        ServerInterceptor binlogInterceptor = getServerInterceptor(oMethodDef.getMethodDescriptor().getFullMethodName());
        if (binlogInterceptor == null) { 
          return oMethodDef;
        }
    
        MethodDescriptor<byte[], byte[]> binMethod = BinaryLogProvider.toByteBufferMethod(oMethodDef.getMethodDescriptor());
        // 包装方法，添加了处理器和监听器
        ServerMethodDefinition<byte[], byte[]> binDef = InternalServerInterceptors.wrapMethod(oMethodDef, binMethod);
        // 创建处理器
        ServerCallHandler<byte[], byte[]> binlogHandler =
                InternalServerInterceptors.interceptCallHandlerCreate(binlogInterceptor, binDef.getServerCallHandler());
        // 创建服务方法定义
        return ServerMethodDefinition.create(binMethod, binlogHandler);
      }

*  io.grpc.services.BinlogHelper\#getClientInterceptor

会在每一个事件中输出具体的信息到 BinaryLog 中

public ClientInterceptor getClientInterceptor(final long callId) { 
        return new ClientInterceptor() { 
          boolean trailersOnlyResponse = true;
    
          @Override
          public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(final MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) { 
            final String methodName = method.getFullMethodName();
            final String authority = next.authority();
            final Deadline deadline = min(callOptions.getDeadline(), Context.current().getDeadline());
    
            return new SimpleForwardingClientCall<ReqT, RespT>(next.newCall(method, callOptions)) { 
              @Override
              public void start(final ClientCall.Listener<RespT> responseListener, Metadata headers) { 
                final Duration timeout = deadline == null ? null : Durations.fromNanos(deadline.timeRemaining(TimeUnit.NANOSECONDS));
                writer.logClientHeader(seq.getAndIncrement(), methodName, authority, timeout, headers, GrpcLogEntry.Logger.LOGGER_CLIENT,callId, /*peerAddress=*/ null);
                ClientCall.Listener<RespT> wListener =
                        new SimpleForwardingClientCallListener<RespT>(responseListener) { 
                          @Override
                          public void onMessage(RespT message) { 
                            writer.logRpcMessage(seq.getAndIncrement(), EventType.EVENT_TYPE_SERVER_MESSAGE, method.getResponseMarshaller(), message, GrpcLogEntry.Logger.LOGGER_CLIENT, callId);
                            super.onMessage(message);
                          }
    
                          @Override
                          public void onHeaders(Metadata headers) { 
                            trailersOnlyResponse = false;
                            writer.logServerHeader(seq.getAndIncrement(), headers, GrpcLogEntry.Logger.LOGGER_CLIENT, callId, getPeerSocket(getAttributes()));
                            super.onHeaders(headers);
                          }
    
                          @Override
                          public void onClose(Status status, Metadata trailers) { 
                            SocketAddress peer = trailersOnlyResponse ? getPeerSocket(getAttributes()) : null;
                            writer.logTrailer(seq.getAndIncrement(), status, trailers, GrpcLogEntry.Logger.LOGGER_CLIENT, callId, peer);
                            super.onClose(status, trailers);
                          }
                        };
                super.start(wListener, headers);
              }
    
              @Override
              public void sendMessage(ReqT message) { 
                writer.logRpcMessage(seq.getAndIncrement(), EventType.EVENT_TYPE_CLIENT_MESSAGE, method.getRequestMarshaller(), message, GrpcLogEntry.Logger.LOGGER_CLIENT, callId);
                super.sendMessage(message);
              }
    
              @Override
              public void halfClose() { 
                writer.logHalfClose(seq.getAndIncrement(), GrpcLogEntry.Logger.LOGGER_CLIENT, callId);
                super.halfClose();
              }
    
              @Override
              public void cancel(String message, Throwable cause) { 
                writer.logCancel(seq.getAndIncrement(), GrpcLogEntry.Logger.LOGGER_CLIENT, callId);
                super.cancel(message, cause);
              }
            };
          }
        };
      }

[Control Interface]: https://github.com/helloworlde/proposal/blob/master/A16-binary-logging.md#control-interface