微服務全鏈路跟蹤：jaeger集成istio，併兼容uber-trace-id與b3

微服務全鏈路跟蹤：grpc集成zipkin

微服務全鏈路跟蹤：grpc集成jaeger

微服務全鏈路跟蹤：springcloud集成jaeger

微服務全鏈路跟蹤：jaeger集成istio，併兼容uber-trace-id與b3

公司有自己的一套基於k8s的paas系統，並且集成了istio，這裏主要是想講解下springcloud服務如何集成istio

jaeger跨進程傳遞

在基於HTTP協議的分佈式調用中，通常會使用HTTP Header來傳遞SpanContext的內容。
常見的Wire Protocol包含Zipkin使用的b3 HTTP header，Jaeger使用的uber-trace-id HTTP Header,LightStep使用的"x-ot-span-context" 等。
Istio1.0支持b3 header和x-ot-span-context header,可以和Zipkin,Jaeger及LightStep對接；istio1.4以上支持uber-trace-id。
注：請參考github官方說明：https://github.com/istio/istio/issues/12400

uber-trace-id

圖中可以看到其中traceId、spanId等字段都拼接到一個key中了

b3

istio的b3頭詳情可以參考：https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers#x-request-id
b3並沒有將字段都拼接，二十單個傳遞，下面是案例：

X-B3-TraceId:427fde2dc7edb084
X-B3-ParentSpanId:427fde2dc7edb084
X-B3-SpanId:827e270489aafbd7
X-B3-Sampled:1

變更jaeger傳輸爲b3

如果需要集成istio的jaeger，則需要將傳輸方式修改爲b3
微服務全鏈路跟蹤：springcloud集成jaeger該章中已經描述瞭如何集成jaeger，這裏只需要修改一個配置enable-b3-propagation，如下

opentracing:
  jaeger:
    enable-b3-propagation: true// 默認爲false
    udp-sender:
      host: localhost
      port: 6831
    remote-reporter:
      flush-interval: 1000
      max-queue-size: 5000
    log-spans: true
    probabilistic-sampler:
      sampling-rate: 1

這樣springboot服務就可以與istio中的jaeger信息串起來形成完整全鏈路。

兼容uber-trace-id與b3

現在遇到了另外一個問題，公司已經很早就搭建了一套全鏈路jaeger，並且已經接入了大部分系統，採用的是默認的header傳輸，即：uber-trace-id
而下游有很多paas內部系統都是非java的不方便接入jaeger，只是注入了istio，並自動注入了jaeger-agent，這裏使用的是b3頭傳輸，這就導致了部分鏈路上下游無法串聯起來。而如果需要統一傳輸方式暫不現實，首先如果都改成b3，則需要上游很多已接入的系統修改配置爲b3，如果是都改成uber-trace-id，istio當前版本不支持，如果需要升級istio，則需要升級kubernetes，風險比較大，所以這裏根據實際情況先採用集成兩種頭，即上游都是uber-trace-id，到中間層服務時手動注入b3相關頭如下。

grpc注入b3頭

這裏需要使用grpc的攔截器

import com.google.common.collect.ImmutableMap;
import io.grpc.*;
import io.opentracing.Span;
import io.opentracing.Tracer;
import io.opentracing.propagation.Format;
import io.opentracing.propagation.TextMap;
import lombok.extern.slf4j.Slf4j;

import javax.annotation.Nullable;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.TimeUnit;

/** 
 * An intercepter that applies tracing via OpenTracing to all client requests. 
 */
@Slf4j
public class ClientTracingInterceptor implements ClientInterceptor {

    private final Tracer tracer;
    private final OperationNameConstructor operationNameConstructor;
    private final boolean streaming;
    private final boolean verbose;
    private final Set<ClientRequestAttribute> tracedAttributes;
    private final ActiveSpanSource activeSpanSource;
    private final  Metadata.Key<String> b3TraceIdKey = Metadata.Key.of("X-B3-TraceId", Metadata.ASCII_STRING_MARSHALLER);
    private final  Metadata.Key<String> b3SpanIdKey = Metadata.Key.of("X-B3-SpanId", Metadata.ASCII_STRING_MARSHALLER);
    private final  Metadata.Key<String> b3ParentSpanIdKey = Metadata.Key.of("X-B3-ParentSpanId", Metadata.ASCII_STRING_MARSHALLER);
    private final  Metadata.Key<String> b3SampledKey = Metadata.Key.of("X-B3-Sampled", Metadata.ASCII_STRING_MARSHALLER);
    /**
     * @param
     */
    public ClientTracingInterceptor(Tracer tracer) {
        this.tracer=tracer;
        this.operationNameConstructor = OperationNameConstructor.DEFAULT;
        this.streaming = false;
        this.verbose = false;
        this.tracedAttributes = new HashSet<ClientRequestAttribute>();
        this.activeSpanSource = ActiveSpanSource.GRPC_CONTEXT;
    }

    private ClientTracingInterceptor(Tracer tracer, OperationNameConstructor operationNameConstructor, boolean streaming,
        boolean verbose, Set<ClientRequestAttribute> tracedAttributes, ActiveSpanSource activeSpanSource) {
        this.tracer = tracer;
        this.operationNameConstructor = operationNameConstructor;
        this.streaming = streaming;
        this.verbose = verbose;
        this.tracedAttributes = tracedAttributes;
        this.activeSpanSource = activeSpanSource;
    }

    /**
     * Use this intercepter to trace all requests made by this client channel.
     * @param channel to be traced
     * @return intercepted channel
     */ 
    public Channel intercept(Channel channel) {
        return ClientInterceptors.intercept(channel, this);
    }

    @Override
    public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
        MethodDescriptor<ReqT, RespT> method, 
        CallOptions callOptions, 
        Channel next
    ) {
        final String operationName = operationNameConstructor.constructOperationName(method);

        Span activeSpan = this.activeSpanSource.getActiveSpan();
        final Span span = createSpanFromParent(activeSpan, operationName);

        for (ClientRequestAttribute attr : this.tracedAttributes) {
            switch (attr) {
                case ALL_CALL_OPTIONS:
                    span.setTag("grpc.call_options", callOptions.toString());
                    break;
                case AUTHORITY:
                    if (callOptions.getAuthority() == null) {
                        span.setTag("grpc.authority", "null");
                    } else {
                        span.setTag("grpc.authority", callOptions.getAuthority());                        
                    }
                    break;
                case COMPRESSOR:
                    if (callOptions.getCompressor() == null) {
                        span.setTag("grpc.compressor", "null");
                    } else {
                        span.setTag("grpc.compressor", callOptions.getCompressor());
                    }
                    break;
                case DEADLINE:
                    if (callOptions.getDeadline() == null) {
                        span.setTag("grpc.deadline_millis", "null");
                    } else {
                        span.setTag("grpc.deadline_millis", callOptions.getDeadline().timeRemaining(TimeUnit.MILLISECONDS));
                    }
                    break;
                case METHOD_NAME:
                    span.setTag("grpc.method_name", method.getFullMethodName());
                    break;
                case METHOD_TYPE:
                    if (method.getType() == null) {
                        span.setTag("grpc.method_type", "null");
                    } else {
                        span.setTag("grpc.method_type", method.getType().toString());
                    }
                    break;
                case HEADERS:
                	break;
            }
        }

        return new ForwardingClientCall.SimpleForwardingClientCall<ReqT, RespT>(next.newCall(method, callOptions)) {

            @Override
            public void start(Listener<RespT> responseListener, Metadata headers) {
                if (verbose) {
                    span.log("Started call");
                }
                if (tracedAttributes.contains(ClientRequestAttribute.HEADERS)) {
                    span.setTag("grpc.headers", headers.toString()); 
                }

                tracer.inject(span.context(), Format.Builtin.HTTP_HEADERS, new TextMap() {
                    @Override
                    public void put(String key, String value) {
                        log.info("jaeger key:{},value:{}",key,value);
                        Metadata.Key<String> headerKey = Metadata.Key.of(key, Metadata.ASCII_STRING_MARSHALLER);
                        headers.put(headerKey, value);
                        String[] mm=value.split("%3A");
                        if("uber-trace-id".equals(key)&&mm.length==4){
                            headers.put(b3TraceIdKey,mm[0]);
                            log.info("jaeger traceId:{}",mm[0]);
                            headers.put(b3SpanIdKey,mm[1]);
                            headers.put(b3ParentSpanIdKey,mm[2]);
                            headers.put(b3SampledKey,mm[3]);
                        }

                    }
					@Override
					public Iterator<Entry<String, String>> iterator() {
						throw new UnsupportedOperationException(
								"TextMapInjectAdapter should only be used with Tracer.inject()");
					}
                });

                Listener<RespT> tracingResponseListener = new ForwardingClientCallListener
                    .SimpleForwardingClientCallListener<RespT>(responseListener) {

                    @Override
                    public void onHeaders(Metadata headers) {
                        if (verbose) { span.log(ImmutableMap.of("Response headers received", headers.toString())); }
                        delegate().onHeaders(headers);
                    }

                    @Override
                    public void onMessage(RespT message) {
                        if (streaming || verbose) { span.log("Response received"); }
                        delegate().onMessage(message);
                    }

                    @Override 
                    public void onClose(Status status, Metadata trailers) {
                        if (verbose) { 
                            if (status.getCode().value() == 0) { span.log("Call closed"); }
                            else { span.log(ImmutableMap.of("Call failed", status.getDescription())); }
                        }
                        span.finish();
                        delegate().onClose(status, trailers);
                    }
                };
                delegate().start(tracingResponseListener, headers);
            }

            @Override 
            public void cancel(@Nullable String message, @Nullable Throwable cause) {
                String errorMessage;
                if (message == null) {
                    errorMessage = "Error";
                } else {
                    errorMessage = message;
                }
                if (cause == null) {
                    span.log(errorMessage);
                } else {
                    span.log(ImmutableMap.of(errorMessage, cause.getMessage()));
                }
                delegate().cancel(message, cause);
            }

            @Override
            public void halfClose() {
                if (streaming) { span.log("Finished sending messages"); }
                delegate().halfClose();
            }

            @Override
            public void sendMessage(ReqT message) {
                if (streaming || verbose) { span.log("Message sent"); }
                delegate().sendMessage(message);
            }
        };
    }
    
    private Span createSpanFromParent(Span parentSpan, String operationName) {
        if (parentSpan == null) {
            return tracer.buildSpan(operationName).startManual();
        } else {
            return tracer.buildSpan(operationName).asChildOf(parentSpan).startManual();
        }
    }

    /**
     * Builds the configuration of a ClientTracingInterceptor.
     */
    public static class Builder {

        private Tracer tracer;
        private OperationNameConstructor operationNameConstructor;
        private boolean streaming;
        private boolean verbose;
        private Set<ClientRequestAttribute> tracedAttributes;
        private ActiveSpanSource activeSpanSource;  

        /**
         * @param tracer to use for this intercepter
         * Creates a Builder with default configuration
         */
        public Builder(Tracer tracer) {
            this.tracer = tracer;
            this.operationNameConstructor = OperationNameConstructor.DEFAULT;
            this.streaming = false;
            this.verbose = false;
            this.tracedAttributes = new HashSet<ClientRequestAttribute>();
            this.activeSpanSource = ActiveSpanSource.GRPC_CONTEXT;
        } 

        /**
         * @param operationNameConstructor to name all spans created by this intercepter
         * @return this Builder with configured operation name
         */
        public Builder withOperationName(OperationNameConstructor operationNameConstructor) {
            this.operationNameConstructor = operationNameConstructor;
            return this;
        } 

        /**
         * Logs streaming events to client spans.
         * @return this Builder configured to log streaming events
         */
        public Builder withStreaming() {
            this.streaming = true;
            return this;
        }

        /**
         * @param tracedAttributes to set as tags on client spans
         *  created by this intercepter
         * @return this Builder configured to trace attributes
         */
        public Builder withTracedAttributes(ClientRequestAttribute... tracedAttributes) {
            this.tracedAttributes = new HashSet<ClientRequestAttribute>(
                Arrays.asList(tracedAttributes));
            return this;
        }

        /**
         * Logs all request life-cycle events to client spans.
         * @return this Builder configured to be verbose
         */
        public Builder withVerbosity() {
            this.verbose = true;
            return this;
        }

        /**
         * @param activeSpanSource that provides a method of getting the 
         *  active span before the client call
         * @return this Builder configured to start client span as children 
         *  of the span returned by activeSpanSource.getActiveSpan()
         */
        public Builder withActiveSpanSource(ActiveSpanSource activeSpanSource) {
            this.activeSpanSource = activeSpanSource;
            return this;
        }

        /**
         * @return a ClientTracingInterceptor with this Builder's configuration
         */
        public ClientTracingInterceptor build() {
            return new ClientTracingInterceptor(this.tracer, this.operationNameConstructor, 
                this.streaming, this.verbose, this.tracedAttributes, this.activeSpanSource);
        }
    }

    public enum ClientRequestAttribute {
        METHOD_TYPE,
        METHOD_NAME,
        DEADLINE,
        COMPRESSOR,
        AUTHORITY,
        ALL_CALL_OPTIONS,
        HEADERS
    }
}

主要改動點在header那一塊

feign注入b3頭

@Configuration
public class FeignConfig implements RequestInterceptor {
	@Autowired
    private final Tracer tracer;
    @Override
    public void apply(RequestTemplate requestTemplate) {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();

        if(attributes!=null&&attributes.getRequest()!=null){
            HttpServletRequest request = attributes.getRequest();

           JaegerSpanContext context=(JaegerSpanContext) tracer.activeSpan().context();
           requestTemplate.header("X-B3-TraceId",String.valueOf(context.getTraceId()));
           requestTemplate.header("X-B3-SpanId", String.valueOf(context.getSpanId()));
           requestTemplate.header("X-B3-ParentSpanId", String.valueOf(context.getParentId()));
           requestTemplate.header("X-B3-Sampled", context.isSampled()?"1":"0");
        }

    }

    @Bean
    Logger.Level feignLoggerLevel() {
        return Logger.Level.FULL;
    }

}

經過手動注入後，就可以實現上下游串起來，暫時達到目標，後面的方案是統一傳輸方式，慢慢升級。