fix interceptor regexp

plugin/grpctrace/interceptor.go

@@ -426,16 +426,15 @@ func peerInfoFromContext(ctx context.Context) []core.KeyValue {
 	return peerInfoFromTarget(p.Addr.String())
 }
 
-var fullMethodRegexp = regexp.MustCompile(`^/\S*\.(\S*)/\S*$`)
+var fullMethodRegexp = regexp.MustCompile(`^\/?(?:\S+\.)?(\S+)\/\S+$`)
 
 func serviceFromFullMethod(method string) string {
-	match := fullMethodRegexp.FindAllStringSubmatch(method, 1)
-
-	if len(match) != 1 && len(match[1]) != 2 {
+	match := fullMethodRegexp.FindStringSubmatch(method)
+	if len(match) == 0 {
 		return ""
 	}
 
-	return match[0][1]
+	return match[1]
 }
 
 func addEventForMessageReceived(ctx context.Context, id int, m interface{}) {

plugin/grpctrace/interceptor_test.go

@@ -0,0 +1,136 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package grpctrace
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"google.golang.org/grpc"
+
+	"go.opentelemetry.io/otel/api/global"
+	export "go.opentelemetry.io/otel/sdk/export/trace"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+)
+
+type testExporter struct {
+	spanMap map[string][]*export.SpanData
+}
+
+func (t *testExporter) ExportSpan(ctx context.Context, s *export.SpanData) {
+	t.spanMap[s.Name] = append(t.spanMap[s.Name], s)
+}
+
+type mockCCInvoker struct {
+	ctx context.Context
+}
+
+func (mcci *mockCCInvoker) invoke(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, opts ...grpc.CallOption) error {
+	mcci.ctx = ctx
+	return nil
+}
+
+type mockProtoMessage struct {
+}
+
+func (mm *mockProtoMessage) Reset()         {}
+func (mm *mockProtoMessage) String() string { return "mock" }
+func (mm *mockProtoMessage) ProtoMessage()  {}
+
+type nameAttributeTestCase struct {
+	testName     string
+	expectedName string
+	fullNameFmt  string
+}
+
+func (tc nameAttributeTestCase) fullName() string {
+	return fmt.Sprintf(tc.fullNameFmt, tc.expectedName)
+}
+
+func TestUCISetsExpectedServiceNameAttribute(t *testing.T) {
+	testCases := []nameAttributeTestCase{
+		{
+			"FullyQualifiedMethodName",
+			"serviceName",
+			"/github.conef.uk.foo.%s/bar",
+		},
+		{
+			"SimpleMethodName",
+			"serviceName",
+			"/%s/bar",
+		},
+		{
+			"MethodNameWithoutFullPath",
+			"serviceName",
+			"%s/bar",
+		},
+		{
+			"InvalidMethodName",
+			"",
+			"invalidName",
+		},
+		{
+			"NonAlhanumericMethodName",
+			"serviceName_123",
+			"/github.conef.uk.foo.%s/method",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.testName, tc.testUCISetsExpectedNameAttribute)
+	}
+}
+
+func (tc nameAttributeTestCase) testUCISetsExpectedNameAttribute(t *testing.T) {
+	exp := &testExporter{make(map[string][]*export.SpanData)}
+	tp, _ := sdktrace.NewProvider(sdktrace.WithSyncer(exp),
+		sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}))
+	global.SetTraceProvider(tp)
+
+	tr := tp.Tracer("grpctrace/client")
+	ctx, span := tr.Start(context.Background(), tc.testName)
+	defer span.End()
+
+	clientConn, err := grpc.Dial("fake:connection", grpc.WithInsecure())
+
+	if err != nil {
+		t.Fatalf("failed to create client connection: %v", err)
+	}
+
+	unaryInt := UnaryClientInterceptor(tr)
+
+	req := &mockProtoMessage{}
+	reply := &mockProtoMessage{}
+	ccInvoker := &mockCCInvoker{}
+
+	err = unaryInt(ctx, tc.fullName(), req, reply, clientConn, ccInvoker.invoke)
+	if err != nil {
+		t.Fatalf("failed to run unary interceptor: %v", err)
+	}
+
+	attributes := exp.spanMap[tc.fullName()][0].Attributes
+
+	var actualServiceName string
+	for _, attr := range attributes {
+		if attr.Key == rpcServiceKey {
+			actualServiceName = attr.Value.AsString()
+		}
+	}
+
+	if tc.expectedName != actualServiceName {
+		t.Fatalf("invalid service name found. expected %s, actual %s",
+			tc.expectedName, actualServiceName)
+	}
+}