Add support to zipkin scribe (#359)

Add a "zipkin-scribe" receiver to handle zipkin v1 thrift spans sent via the scribe protocol.

Author: Paulo Janotti

cmd/ocagent/main.go

@@ -39,6 +39,7 @@ import (
 	"github.com/census-instrumentation/opencensus-service/receiver/jaeger"
 	"github.com/census-instrumentation/opencensus-service/receiver/opencensus"
 	"github.com/census-instrumentation/opencensus-service/receiver/zipkin"
+	"github.com/census-instrumentation/opencensus-service/receiver/zipkin/scribe"
 )
 
 var configYAMLFile string
@@ -117,6 +118,14 @@ func runOCAgent() {
 		closeFns = append(closeFns, zipkinReceiverDoneFn)
 	}
 
+	if agentConfig.ZipkinScribeReceiverEnabled() {
+		zipkinScribeDoneFn, err := runZipkinScribeReceiver(agentConfig.ZipkinScribeConfig(), commonSpanSink)
+		if err != nil {
+			log.Fatal(err)
+		}
+		closeFns = append(closeFns, zipkinScribeDoneFn)
+	}
+
 	if agentConfig.JaegerReceiverEnabled() {
 		collectorHTTPPort, collectorThriftPort := agentConfig.JaegerReceiverPorts()
 		jaegerDoneFn, err := runJaegerReceiver(collectorThriftPort, collectorHTTPPort, commonSpanSink)
@@ -243,3 +252,19 @@ func runZipkinReceiver(addr string, sr receiver.TraceReceiverSink) (doneFn func(
 	log.Printf("Running Zipkin receiver with address %q", addr)
 	return doneFn, nil
 }
+
+func runZipkinScribeReceiver(config *config.ScribeReceiverConfig, sr receiver.TraceReceiverSink) (doneFn func() error, err error) {
+	zs, err := scribe.NewReceiver(config.Address, config.Port, config.Category)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to create the Zipkin Scribe receiver: %v", err)
+	}
+
+	if err := zs.StartTraceReception(context.Background(), sr); err != nil {
+		return nil, fmt.Errorf("Cannot start Zipkin Scribe receiver with %v: %v", config, err)
+	}
+	doneFn = func() error {
+		return zs.StopTraceReception(context.Background())
+	}
+	log.Printf("Running Zipkin Scribe receiver with %+v", *config)
+	return doneFn, nil
+}

cmd/occollector/app/builder/builder.go

@@ -23,17 +23,19 @@ import (
 )
 
 const (
-	receiversRoot   = "receivers"
-	jaegerEntry     = "jaeger"
-	opencensusEntry = "opencensus"
-	zipkinEntry     = "zipkin"
+	receiversRoot     = "receivers"
+	jaegerEntry       = "jaeger"
+	opencensusEntry   = "opencensus"
+	zipkinEntry       = "zipkin"
+	zipkinScribeEntry = "zipkin-scribe"
 
 	// flags
-	configCfg         = "config"
-	jaegerReceiverFlg = "receive-jaeger"
-	ocReceiverFlg     = "receive-oc-trace"
-	zipkinReceiverFlg = "receive-zipkin"
-	debugProcessorFlg = "debug-processor"
+	configCfg               = "config"
+	jaegerReceiverFlg       = "receive-jaeger"
+	ocReceiverFlg           = "receive-oc-trace"
+	zipkinReceiverFlg       = "receive-zipkin"
+	zipkinScribeReceiverFlg = "receive-zipkin-scribe"
+	debugProcessorFlg       = "debug-processor"
 )
 
 // Flags adds flags related to basic building of the collector application to the given flagset.
@@ -45,6 +47,8 @@ func Flags(flags *flag.FlagSet) {
 		fmt.Sprintf("Flag to run the OpenCensus trace receiver, default settings: %+v", *NewDefaultOpenCensusReceiverCfg()))
 	flags.Bool(zipkinReceiverFlg, false,
 		fmt.Sprintf("Flag to run the Zipkin receiver, default settings: %+v", *NewDefaultZipkinReceiverCfg()))
+	flags.Bool(zipkinScribeReceiverFlg, false,
+		fmt.Sprintf("Flag to run the Zipkin Scribe receiver, default settings: %+v", *NewDefaultZipkinScribeReceiverCfg()))
 	flags.Bool(debugProcessorFlg, false, "Flag to add a debug processor (combine with log level DEBUG to log incoming spans)")
 }
 
@@ -136,6 +140,41 @@ func (cfg *ZipkinReceiverCfg) InitFromViper(v *viper.Viper) (*ZipkinReceiverCfg,
 	return cfg, initFromViper(cfg, v, receiversRoot, zipkinEntry)
 }
 
+// ScribeReceiverCfg carries the settings for the Zipkin Scribe receiver.
+type ScribeReceiverCfg struct {
+	// Address is an IP address or a name that can be resolved to a local address.
+	//
+	// It can use a name, but this is not recommended, because it will create
+	// a listener for at most one of the host's IP addresses.
+	//
+	// The default value bind to all available interfaces on the local computer.
+	Address string `mapstructure:"address"`
+	Port    uint16 `mapstructure:"port"`
+	// Category is the string that will be used to identify the scribe log messages
+	// that contain Zipkin spans.
+	Category string `mapstructure:"category"`
+}
+
+// ZipkinScribeReceiverEnabled checks if the Zipkin Scribe receiver is enabled, via a command-line flag, environment
+// variable, or configuration file.
+func ZipkinScribeReceiverEnabled(v *viper.Viper) bool {
+	return featureEnabled(v, zipkinScribeReceiverFlg, receiversRoot, zipkinScribeEntry)
+}
+
+// NewDefaultZipkinScribeReceiverCfg returns an instance of config.ScribeReceiverConfig with default values.
+func NewDefaultZipkinScribeReceiverCfg() *ScribeReceiverCfg {
+	opts := &ScribeReceiverCfg{
+		Port:     9410,
+		Category: "zipkin",
+	}
+	return opts
+}
+
+// InitFromViper returns a ScribeReceiverCfg according to the configuration.
+func (cfg *ScribeReceiverCfg) InitFromViper(v *viper.Viper) (*ScribeReceiverCfg, error) {
+	return cfg, initFromViper(cfg, v, receiversRoot, zipkinEntry)
+}
+
 // Helper functions
 
 func initFromViper(cfg interface{}, v *viper.Viper, labels ...string) error {

cmd/occollector/app/builder/builder_test.go

@@ -28,9 +28,10 @@ func TestReceiversEnabledByPresenceWithDefaultSettings(t *testing.T) {
 		t.Fatalf("Failed to load viper from test file: %v", err)
 	}
 
-	jaegerEnabled, opencensusEnabled, zipkinEnabled := JaegerReceiverEnabled(v), OpenCensusReceiverEnabled(v), ZipkinReceiverEnabled(v)
-	if !jaegerEnabled || !opencensusEnabled || !zipkinEnabled {
-		t.Fatalf("Some of the expected receivers were not enabled j:%v oc:%v z:%v", jaegerEnabled, opencensusEnabled, zipkinEnabled)
+	jaegerEnabled, opencensusEnabled, zipkinEnabled, scribeEnabled :=
+		JaegerReceiverEnabled(v), OpenCensusReceiverEnabled(v), ZipkinReceiverEnabled(v), ZipkinScribeReceiverEnabled(v)
+	if !jaegerEnabled || !opencensusEnabled || !zipkinEnabled || !scribeEnabled {
+		t.Fatalf("Some of the expected receivers were not enabled j:%v oc:%v z:%v scribe:%v", jaegerEnabled, opencensusEnabled, zipkinEnabled, scribeEnabled)
 	}
 
 	wj := NewDefaultJaegerReceiverCfg()
@@ -56,6 +57,14 @@ func TestReceiversEnabledByPresenceWithDefaultSettings(t *testing.T) {
 	} else if !reflect.DeepEqual(wz, gz) {
 		t.Errorf("Incorrect config for Zipkin receiver, want %v got %v", wz, gz)
 	}
+
+	wscrb := NewDefaultZipkinScribeReceiverCfg()
+	gscrb, err := wscrb.InitFromViper(v)
+	if err != nil {
+		t.Errorf("Failed to InitFromViper for Zipkin Scribe receiver: %v", err)
+	} else if !reflect.DeepEqual(wscrb, gscrb) {
+		t.Errorf("Incorrect config for Zipkin Scribe receiver, want %v got %v", wscrb, gscrb)
+	}
 }
 
 func TestReceiversDisabledByPresenceWithDefaultSettings(t *testing.T) {
@@ -64,9 +73,10 @@ func TestReceiversDisabledByPresenceWithDefaultSettings(t *testing.T) {
 		t.Fatalf("Failed to load viper from test file: %v", err)
 	}
 
-	jaegerEnabled, opencensusEnabled, zipkinEnabled := JaegerReceiverEnabled(v), OpenCensusReceiverEnabled(v), ZipkinReceiverEnabled(v)
+	jaegerEnabled, opencensusEnabled, zipkinEnabled, scribeEnabled :=
+		JaegerReceiverEnabled(v), OpenCensusReceiverEnabled(v), ZipkinReceiverEnabled(v), ZipkinScribeReceiverEnabled(v)
 	if jaegerEnabled || opencensusEnabled || zipkinEnabled {
-		t.Fatalf("Not all receivers were disabled j:%v oc:%v z:%v", jaegerEnabled, opencensusEnabled, zipkinEnabled)
+		t.Fatalf("Not all receivers were disabled j:%v oc:%v z:%v scribe:%v", jaegerEnabled, opencensusEnabled, zipkinEnabled, scribeEnabled)
 	}
 }
 

cmd/occollector/app/builder/testdata/receivers_disabled.yaml

@@ -3,3 +3,4 @@ receivers:
   # jaeger: {} 
   # opencensus: {}
   # zipkin: {}
+  # zipkin-scribe: {}

cmd/occollector/app/builder/testdata/receivers_enabled.yaml

@@ -3,3 +3,4 @@ receivers:
   jaeger: {} 
   opencensus: {}
   zipkin: {}
+  zipkin-scribe: {}

cmd/occollector/app/collector/receivers.go

@@ -26,6 +26,7 @@ import (
 	"github.com/census-instrumentation/opencensus-service/internal/collector/opencensus"
 	"github.com/census-instrumentation/opencensus-service/internal/collector/processor"
 	"github.com/census-instrumentation/opencensus-service/internal/collector/zipkin"
+	"github.com/census-instrumentation/opencensus-service/internal/collector/zipkin/scribe"
 	"github.com/census-instrumentation/opencensus-service/receiver"
 )
 
@@ -39,6 +40,7 @@ func createReceivers(v *viper.Viper, logger *zap.Logger, spanProcessor processor
 		{"Jaeger", jaegerreceiver.Start, builder.JaegerReceiverEnabled(v)},
 		{"OpenCensus", ocreceiver.Start, builder.OpenCensusReceiverEnabled(v)},
 		{"Zipkin", zipkinreceiver.Start, builder.ZipkinReceiverEnabled(v)},
+		{"Zipkin-Scribe", zipkinscribereceiver.Start, builder.ZipkinScribeReceiverEnabled(v)},
 	}
 
 	var startedTraceReceivers []receiver.TraceReceiver

go.mod

@@ -4,7 +4,7 @@ require (
 	cloud.google.com/go v0.32.0 // indirect
 	contrib.go.opencensus.io/exporter/ocagent v0.4.3
 	contrib.go.opencensus.io/exporter/stackdriver v0.9.1
-	git.apache.org/thrift.git v0.0.0-20181101003639-92be4f312b88 // indirect
+	git.apache.org/thrift.git v0.0.0-20181101003639-92be4f312b88
 	github.com/BurntSushi/toml v0.3.1 // indirect
 	github.com/DataDog/datadog-go v0.0.0-20180822151419-281ae9f2d895 // indirect
 	github.com/DataDog/opencensus-go-exporter-datadog v0.0.0-20181026070331-e7c4bd17b329
@@ -26,6 +26,7 @@ require (
 	github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af // indirect
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/mitchellh/mapstructure v1.1.2 // indirect
+	github.com/omnition/scribe-go v0.0.0-20190131012523-9e3c68f31124
 	github.com/opentracing/opentracing-go v1.0.2 // indirect
 	github.com/openzipkin/zipkin-go v0.1.3
 	github.com/orijtech/prometheus-go-metrics-exporter v0.0.2
@@ -34,6 +35,7 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prashantv/protectmem v0.0.0-20171002184600-e20412882b3a // indirect
 	github.com/prometheus/client_golang v0.8.0
+	github.com/prometheus/procfs v0.0.0-20180725123919-05ee40e3a273
 	github.com/rs/cors v1.6.0
 	github.com/soheilhy/cmux v0.1.4
 	github.com/spf13/cast v1.2.0
@@ -57,6 +59,7 @@ require (
 	golang.org/x/net v0.0.0-20181102091132-c10e9556a7bc
 	golang.org/x/oauth2 v0.0.0-20181102170140-232e45548389 // indirect
 	golang.org/x/sys v0.0.0-20181031143558-9b800f95dbbc // indirect
+	golang.org/x/text v0.3.0
 	google.golang.org/api v0.0.0-20181102150758-04bb50b6b83d
 	google.golang.org/appengine v1.3.0 // indirect
 	google.golang.org/genproto v0.0.0-20181101192439-c830210a61df // indirect

go.sum

@@ -7,13 +7,15 @@ cloud.google.com/go v0.32.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMT
 contrib.go.opencensus.io/exporter/ocagent v0.3.0 h1:fyqPXp7d+BBV3tXa7EE1CYrObJr7R9jTAOO/AsdcQBg=
 contrib.go.opencensus.io/exporter/ocagent v0.3.0/go.mod h1:0fnkYHF+ORKj7HWzOExKkUHeFX79gXSKUQbpnAM+wzo=
 contrib.go.opencensus.io/exporter/ocagent v0.4.2/go.mod h1:YuG83h+XWwqWjvCqn7vK4KSyLKhThY3+gNGQ37iS2V0=
+contrib.go.opencensus.io/exporter/ocagent v0.4.3 h1:QjNm697iO7CZ09IxxSiCUzOhALENIsLsixdPwjV1yGs=
 contrib.go.opencensus.io/exporter/ocagent v0.4.3/go.mod h1:YuG83h+XWwqWjvCqn7vK4KSyLKhThY3+gNGQ37iS2V0=
 contrib.go.opencensus.io/exporter/stackdriver v0.7.0 h1:pmo1ol3uPcrLmvOET8bEbu5sialRZDDSHqJso0vo28o=
 contrib.go.opencensus.io/exporter/stackdriver v0.7.0/go.mod h1:hNe5qQofPbg6bLQY5wHCvQ7o+2E5P8PkegEuQ+MyRw0=
 contrib.go.opencensus.io/exporter/stackdriver v0.9.1 h1:W6APgQ9we4BH8U8bnq/FvwLKo2WSMHuiMkkS/Slkg30=
 contrib.go.opencensus.io/exporter/stackdriver v0.9.1/go.mod h1:hNe5qQofPbg6bLQY5wHCvQ7o+2E5P8PkegEuQ+MyRw0=
 git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999 h1:sihTnRgTOUSCQz0iS0pjZuFQy/z7GXCJgSBg3+rZKHw=
 git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999/go.mod h1:fPE2ZNJGynbRyZ4dJvy6G277gSllfV2HJqblrnkyeyg=
+git.apache.org/thrift.git v0.0.0-20181101003639-92be4f312b88 h1:c+lV5k88kQl9zle5Wstbsf1rW2Y9bMfuVyhJeIk5hgM=
 git.apache.org/thrift.git v0.0.0-20181101003639-92be4f312b88/go.mod h1:fPE2ZNJGynbRyZ4dJvy6G277gSllfV2HJqblrnkyeyg=
 github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
@@ -27,6 +29,7 @@ github.com/Shopify/toxiproxy v2.1.3+incompatible h1:awiJqUYH4q4OmoBiRccJykjd7B+w
 github.com/Shopify/toxiproxy v2.1.3+incompatible/go.mod h1:OXgGpZ6Cli1/URJOF1DMxUHB2q5Ap20/P/eIdh4G0pI=
 github.com/VividCortex/gohistogram v1.0.0 h1:6+hBz+qvs0JOrrNhhmR7lFxo5sINxBCGXrdtl/UvroE=
 github.com/VividCortex/gohistogram v1.0.0/go.mod h1:Pf5mBqqDxYaXu3hDrrU+w6nw50o/4+TcAqDqk/vUH7g=
+github.com/apache/thrift v0.0.0-20161221203622-b2a4d4ae21c7 h1:Fv9bK1Q+ly/ROk4aJsVMeuIwPel4bEnD8EPiI91nZMg=
 github.com/apache/thrift v0.0.0-20161221203622-b2a4d4ae21c7/go.mod h1:cp2SuWMxlEZw2r+iP2GNCdIi4C1qmUzdZFSVb+bacwQ=
 github.com/apache/thrift v0.0.0-20161221203622-b2a4d4ae21c7/go.mod h1:cp2SuWMxlEZw2r+iP2GNCdIi4C1qmUzdZFSVb+bacwQ=
 github.com/aws/aws-sdk-go v1.15.31/go.mod h1:mFuSZ37Z9YOHbQEwBWztmVzqXrEkub65tZoCYDt7FT0=
@@ -107,6 +110,8 @@ github.com/mitchellh/mapstructure v1.0.0 h1:vVpGvMXJPqSDh2VYHF7gsfQj8Ncx+Xw5Y1KH
 github.com/mitchellh/mapstructure v1.0.0/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/omnition/scribe-go v0.0.0-20190131012523-9e3c68f31124 h1:mJ3GKMlsntao+kIP06AjcDxTQ5M4uG+cFKp8rRLTJG8=
+github.com/omnition/scribe-go v0.0.0-20190131012523-9e3c68f31124/go.mod h1:GnPmaNTr3pdt/V0JmVNVgDq+JEMb/oXxNlsG+pN6gg4=
 github.com/opentracing/opentracing-go v1.0.2 h1:3jA2P6O1F9UOrWVpwrIo17pu01KWvNWg4X946/Y5Zwg=
 github.com/opentracing/opentracing-go v1.0.2/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/openzipkin/zipkin-go v0.1.1/go.mod h1:NtoC/o8u3JlF1lSlyPNswIbeQH9bJTmOf0Erfk+hxe8=

internal/collector/zipkin/scribe/receiver.go

@@ -0,0 +1,52 @@
+// Copyright 2019, OpenCensus 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 zipkinscribereceiver wraps the functionality to start the end-point that
+// receives Zipkin Scribe spans.
+package zipkinscribereceiver
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/spf13/viper"
+	"go.uber.org/zap"
+
+	"github.com/census-instrumentation/opencensus-service/cmd/occollector/app/builder"
+	"github.com/census-instrumentation/opencensus-service/internal/collector/processor"
+	"github.com/census-instrumentation/opencensus-service/receiver"
+	"github.com/census-instrumentation/opencensus-service/receiver/zipkin/scribe"
+)
+
+// Start starts the Zipkin Scribe receiver endpoint.
+func Start(logger *zap.Logger, v *viper.Viper, spanProc processor.SpanProcessor) (receiver.TraceReceiver, error) {
+	rOpts, err := builder.NewDefaultZipkinScribeReceiverCfg().InitFromViper(v)
+	if err != nil {
+		return nil, err
+	}
+
+	sr, err := scribe.NewReceiver(rOpts.Address, rOpts.Port, rOpts.Category)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to create the Zipkin Scribe receiver: %v", err)
+	}
+	ss := processor.WrapWithSpanSink("zipkin-scribe", spanProc)
+
+	if err := sr.StartTraceReception(context.Background(), ss); err != nil {
+		return nil, fmt.Errorf("Cannot start Zipkin Scribe receiver %+v: %v", rOpts, err)
+	}
+
+	logger.Info("Zipkin Scribe receiver is running.", zap.Uint16("port", rOpts.Port), zap.String("category", rOpts.Category))
+
+	return sr, nil
+}

internal/config/config.go

@@ -53,6 +53,11 @@ const (
 
 var defaultOCReceiverCorsAllowedOrigins = []string{}
 
+var defaultScribeConfiguration = &ScribeReceiverConfig{
+	Port:     9410,
+	Category: "zipkin",
+}
+
 // Config denotes the configuration for the various elements of an agent, that is:
 // * Receivers
 // * ZPages
@@ -68,9 +73,10 @@ type Config struct {
 // * OpenCensus
 // * Zipkin
 type Receivers struct {
-	OpenCensus *ReceiverConfig `yaml:"opencensus"`
-	Zipkin     *ReceiverConfig `yaml:"zipkin"`
-	Jaeger     *ReceiverConfig `yaml:"jaeger"`
+	OpenCensus *ReceiverConfig       `yaml:"opencensus"`
+	Zipkin     *ReceiverConfig       `yaml:"zipkin"`
+	Jaeger     *ReceiverConfig       `yaml:"jaeger"`
+	Scribe     *ScribeReceiverConfig `yaml:"zipkin-scribe"`
 }
 
 // ReceiverConfig is the per-receiver configuration that identifies attributes
@@ -95,6 +101,21 @@ type ReceiverConfig struct {
 	DisableMetrics bool `yaml:"disable_metrics"`
 }
 
+// ScribeReceiverConfig carries the settings for the Zipkin Scribe receiver.
+type ScribeReceiverConfig struct {
+	// Address is an IP address or a name that can be resolved to a local address.
+	//
+	// It can use a name, but this is not recommended, because it will create
+	// a listener for at most one of the host's IP addresses.
+	//
+	// The default value bind to all available interfaces on the local computer.
+	Address string `yaml:"address" mapstructure:"address"`
+	Port    uint16 `yaml:"port" mapstructure:"port"`
+	// Category is the string that will be used to identify the scribe log messages
+	// that contain Zipkin spans.
+	Category string `yaml:"category" mapstructure:"category"`
+}
+
 // Exporters denotes the configurations for the various backends
 // that this service exports observability signals to.
 type Exporters struct {
@@ -180,6 +201,15 @@ func (c *Config) ZipkinReceiverEnabled() bool {
 	return c.Receivers != nil && c.Receivers.Zipkin != nil
 }
 
+// ZipkinScribeReceiverEnabled returns true if Config is non-nil
+// and if the Scribe receiver configuration is also non-nil.
+func (c *Config) ZipkinScribeReceiverEnabled() bool {
+	if c == nil {
+		return false
+	}
+	return c.Receivers != nil && c.Receivers.Scribe != nil
+}
+
 // JaegerReceiverEnabled returns true if Config is non-nil
 // and if the Jaeger receiver configuration is also non-nil.
 func (c *Config) JaegerReceiverEnabled() bool {
@@ -204,6 +234,22 @@ func (c *Config) ZipkinReceiverAddress() string {
 	return inCfg.Zipkin.Address
 }
 
+// ZipkinScribeConfig is a helper to safely retrieve the Zipkin Scribe
+// configuration.
+func (c *Config) ZipkinScribeConfig() *ScribeReceiverConfig {
+	if c == nil || c.Receivers == nil || c.Receivers.Scribe == nil {
+		return defaultScribeConfiguration
+	}
+	cfg := c.Receivers.Scribe
+	if cfg.Port == 0 {
+		cfg.Port = defaultScribeConfiguration.Port
+	}
+	if cfg.Category == "" {
+		cfg.Category = defaultScribeConfiguration.Category
+	}
+	return cfg
+}
+
 // JaegerReceiverPorts is a helper to safely retrieve the address
 // that the Jaeger receiver will run on.
 func (c *Config) JaegerReceiverPorts() (collectorPort, thriftPort int) {