Add logging options to jaeger.sampler (#2566)

* add logger option

* replace logr.Logger with NullLogger

* Fix import format error

* fix go.mod and go.sum

* add changelog

* use logr.Logger

* go mod tidy

* fix go.sum

* change option name

* fix changelog
default use NullLogger

* use logr.Discard

* change info to error

* fix changelog

* docs: remove useless text

* fix: dependabot config

CHANGELOG.md

@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Added
 
+- The `WithLogger` option to `go.opentelemetry.io/contrib/samplers/jaegerremote` to allow users to pass a `logr.Logger` and have operations logged. (#2566)
 - Add the `messaging.url` & `messaging.system` attributes to all appropriate SQS operations in the `go.opentelemetry.io/contrib/instrumentation/github.com/aws/aws-sdk-go-v2/otelaws` package. (#2879)
 
 ## [1.11.1/0.36.4/0.5.2]

samplers/jaegerremote/go.mod

@@ -3,19 +3,19 @@ module go.opentelemetry.io/contrib/samplers/jaegerremote
 go 1.18
 
 require (
+	github.com/go-logr/logr v1.2.3
 	github.com/gogo/protobuf v1.3.2
 	github.com/stretchr/testify v1.8.1
-	go.opentelemetry.io/otel v1.11.1
 	go.opentelemetry.io/otel/sdk v1.11.1
 	go.opentelemetry.io/otel/trace v1.11.1
 	google.golang.org/genproto v0.0.0-20211208223120-3a66f561d7aa
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel v1.11.1 // indirect
 	golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

samplers/jaegerremote/sampler_remote.go

@@ -27,7 +27,6 @@ import (
 	"time"
 
 	jaeger_api_v2 "go.opentelemetry.io/contrib/samplers/jaegerremote/internal/proto-gen/jaeger-idl/proto/api_v2"
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/sdk/trace"
 )
 
@@ -105,7 +104,7 @@ func (s *Sampler) ShouldSample(p trace.SamplingParameters) trace.SamplingResult
 // go-routines it may have started.
 func (s *Sampler) Close() {
 	if swapped := atomic.CompareAndSwapInt64(&s.closed, 0, 1); !swapped {
-		otel.Handle(fmt.Errorf("repeated attempt to close the sampler is ignored"))
+		s.logger.Info("repeated attempt to close the sampler is ignored")
 		return
 	}
 
@@ -151,20 +150,20 @@ func (s *Sampler) setSampler(sampler trace.Sampler) {
 func (s *Sampler) UpdateSampler() {
 	res, err := s.samplingFetcher.Fetch(s.serviceName)
 	if err != nil {
-		// log.Printf("failed to fetch sampling strategy: %v", err)
+		s.logger.Error(err, "failed to fetch sampling strategy")
 		return
 	}
 	strategy, err := s.samplingParser.Parse(res)
 	if err != nil {
-		// log.Printf("failed to parse sampling strategy response: %v", err)
+		s.logger.Error(err, "failed to parse sampling strategy response")
 		return
 	}
 
 	s.Lock()
 	defer s.Unlock()
 
 	if err := s.updateSamplerViaUpdaters(strategy); err != nil {
-		// c.logger.Infof("failed to handle sampling strategy response %+v. Got error: %v", res, err)
+		s.logger.Error(err, "failed to handle sampling strategy response", "response", res)
 		return
 	}
 }

samplers/jaegerremote/sampler_remote_options.go

@@ -19,6 +19,8 @@ package jaegerremote // import "go.opentelemetry.io/contrib/samplers/jaegerremot
 import (
 	"time"
 
+	"github.com/go-logr/logr"
+
 	"go.opentelemetry.io/otel/sdk/trace"
 )
 
@@ -30,6 +32,7 @@ type config struct {
 	samplingParser          samplingStrategyParser
 	updaters                []samplerUpdater
 	posParams               perOperationSamplerParams
+	logger                  logr.Logger
 }
 
 // newConfig returns an appropriately configured config.
@@ -48,6 +51,7 @@ func newConfig(options ...Option) config {
 			MaxOperations:            defaultSamplingMaxOperations,
 			OperationNameLateBinding: defaultSamplingOperationNameLateBinding,
 		},
+		logger: logr.Discard(),
 	}
 	for _, option := range options {
 		option.apply(&c)
@@ -112,6 +116,13 @@ func WithSamplingRefreshInterval(samplingRefreshInterval time.Duration) Option {
 	})
 }
 
+// WithLogger configures the sampler to log operation and debug information with logger.
+func WithLogger(logger logr.Logger) Option {
+	return optionFunc(func(c *config) {
+		c.logger = logger
+	})
+}
+
 // samplingStrategyFetcher creates a Option that initializes sampling strategy fetcher.
 func withSamplingStrategyFetcher(fetcher samplingStrategyFetcher) Option {
 	return optionFunc(func(c *config) {

samplers/jaegerremote/sampler_remote_test.go

@@ -23,6 +23,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/go-logr/logr/testr"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -112,6 +113,7 @@ func TestRemoteSamplerOptions(t *testing.T) {
 	initSampler := newProbabilisticSampler(0.123)
 	fetcher := new(fakeSamplingFetcher)
 	parser := new(samplingStrategyParserImpl)
+	logger := testr.New(t)
 	updaters := []samplerUpdater{new(probabilisticSamplerUpdater)}
 	sampler := New(
 		"test",
@@ -123,6 +125,7 @@ func TestRemoteSamplerOptions(t *testing.T) {
 		withSamplingStrategyFetcher(fetcher),
 		withSamplingStrategyParser(parser),
 		withUpdaters(updaters...),
+		WithLogger(logger),
 	)
 	assert.Equal(t, 42, sampler.posParams.MaxOperations)
 	assert.True(t, sampler.posParams.OperationNameLateBinding)
@@ -132,6 +135,7 @@ func TestRemoteSamplerOptions(t *testing.T) {
 	assert.Same(t, fetcher, sampler.samplingFetcher)
 	assert.Same(t, parser, sampler.samplingParser)
 	assert.EqualValues(t, sampler.updaters[0], &perOperationSamplerUpdater{MaxOperations: 42, OperationNameLateBinding: true})
+	assert.Equal(t, logger, sampler.logger)
 }
 
 func TestRemoteSamplerOptionsDefaults(t *testing.T) {