vendor: add buildkit

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc/server.go

@@ -0,0 +1,141 @@
+package otgrpc
+
+import (
+	"github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go/ext"
+	"github.com/opentracing/opentracing-go/log"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+// OpenTracingServerInterceptor returns a grpc.UnaryServerInterceptor suitable
+// for use in a grpc.NewServer call.
+//
+// For example:
+//
+//     s := grpc.NewServer(
+//         ...,  // (existing ServerOptions)
+//         grpc.UnaryInterceptor(otgrpc.OpenTracingServerInterceptor(tracer)))
+//
+// All gRPC server spans will look for an OpenTracing SpanContext in the gRPC
+// metadata; if found, the server span will act as the ChildOf that RPC
+// SpanContext.
+//
+// Root or not, the server Span will be embedded in the context.Context for the
+// application-specific gRPC handler(s) to access.
+func OpenTracingServerInterceptor(tracer opentracing.Tracer, optFuncs ...Option) grpc.UnaryServerInterceptor {
+	otgrpcOpts := newOptions()
+	otgrpcOpts.apply(optFuncs...)
+	return func(
+		ctx context.Context,
+		req interface{},
+		info *grpc.UnaryServerInfo,
+		handler grpc.UnaryHandler,
+	) (resp interface{}, err error) {
+		spanContext, err := extractSpanContext(ctx, tracer)
+		if err != nil && err != opentracing.ErrSpanContextNotFound {
+			// TODO: establish some sort of error reporting mechanism here. We
+			// don't know where to put such an error and must rely on Tracer
+			// implementations to do something appropriate for the time being.
+		}
+		if otgrpcOpts.inclusionFunc != nil &&
+			!otgrpcOpts.inclusionFunc(spanContext, info.FullMethod, req, nil) {
+			return handler(ctx, req)
+		}
+		serverSpan := tracer.StartSpan(
+			info.FullMethod,
+			ext.RPCServerOption(spanContext),
+			gRPCComponentTag,
+		)
+		defer serverSpan.Finish()
+
+		ctx = opentracing.ContextWithSpan(ctx, serverSpan)
+		if otgrpcOpts.logPayloads {
+			serverSpan.LogFields(log.Object("gRPC request", req))
+		}
+		resp, err = handler(ctx, req)
+		if err == nil {
+			if otgrpcOpts.logPayloads {
+				serverSpan.LogFields(log.Object("gRPC response", resp))
+			}
+		} else {
+			SetSpanTags(serverSpan, err, false)
+			serverSpan.LogFields(log.String("event", "error"), log.String("message", err.Error()))
+		}
+		if otgrpcOpts.decorator != nil {
+			otgrpcOpts.decorator(serverSpan, info.FullMethod, req, resp, err)
+		}
+		return resp, err
+	}
+}
+
+// OpenTracingStreamServerInterceptor returns a grpc.StreamServerInterceptor suitable
+// for use in a grpc.NewServer call. The interceptor instruments streaming RPCs by
+// creating a single span to correspond to the lifetime of the RPC's stream.
+//
+// For example:
+//
+//     s := grpc.NewServer(
+//         ...,  // (existing ServerOptions)
+//         grpc.StreamInterceptor(otgrpc.OpenTracingStreamServerInterceptor(tracer)))
+//
+// All gRPC server spans will look for an OpenTracing SpanContext in the gRPC
+// metadata; if found, the server span will act as the ChildOf that RPC
+// SpanContext.
+//
+// Root or not, the server Span will be embedded in the context.Context for the
+// application-specific gRPC handler(s) to access.
+func OpenTracingStreamServerInterceptor(tracer opentracing.Tracer, optFuncs ...Option) grpc.StreamServerInterceptor {
+	otgrpcOpts := newOptions()
+	otgrpcOpts.apply(optFuncs...)
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		spanContext, err := extractSpanContext(ss.Context(), tracer)
+		if err != nil && err != opentracing.ErrSpanContextNotFound {
+			// TODO: establish some sort of error reporting mechanism here. We
+			// don't know where to put such an error and must rely on Tracer
+			// implementations to do something appropriate for the time being.
+		}
+		if otgrpcOpts.inclusionFunc != nil &&
+			!otgrpcOpts.inclusionFunc(spanContext, info.FullMethod, nil, nil) {
+			return handler(srv, ss)
+		}
+
+		serverSpan := tracer.StartSpan(
+			info.FullMethod,
+			ext.RPCServerOption(spanContext),
+			gRPCComponentTag,
+		)
+		defer serverSpan.Finish()
+		ss = &openTracingServerStream{
+			ServerStream: ss,
+			ctx:          opentracing.ContextWithSpan(ss.Context(), serverSpan),
+		}
+		err = handler(srv, ss)
+		if err != nil {
+			SetSpanTags(serverSpan, err, false)
+			serverSpan.LogFields(log.String("event", "error"), log.String("message", err.Error()))
+		}
+		if otgrpcOpts.decorator != nil {
+			otgrpcOpts.decorator(serverSpan, info.FullMethod, nil, nil, err)
+		}
+		return err
+	}
+}
+
+type openTracingServerStream struct {
+	grpc.ServerStream
+	ctx context.Context
+}
+
+func (ss *openTracingServerStream) Context() context.Context {
+	return ss.ctx
+}
+
+func extractSpanContext(ctx context.Context, tracer opentracing.Tracer) (opentracing.SpanContext, error) {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		md = metadata.New(nil)
+	}
+	return tracer.Extract(opentracing.HTTPHeaders, metadataReaderWriter{md})
+}