init (#1)

https://coralogix.atlassian.net/browse/VV-619

.gitignore

@@ -0,0 +1 @@
+/.idea/

go.mod

@@ -0,0 +1,20 @@
+module com.coralogix.opentelemetry-go
+
+go 1.17
+
+require (
+	github.com/stretchr/testify v1.8.1
+	go.opentelemetry.io/otel v1.11.2
+	go.opentelemetry.io/otel/sdk v1.11.2
+	go.opentelemetry.io/otel/trace v1.11.2
+
+)
+
+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
+	golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,32 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+go.opentelemetry.io/otel v1.11.2 h1:YBZcQlsVekzFsFbjygXMOXSs6pialIZxcjfO/mBDmR0=
+go.opentelemetry.io/otel v1.11.2/go.mod h1:7p4EUV+AqgdlNV9gL97IgUZiVR3yrFXYo53f9BM3tRI=
+go.opentelemetry.io/otel/sdk v1.11.2 h1:GF4JoaEx7iihdMFu30sOyRx52HDHOkl9xQ8SMqNXUiU=
+go.opentelemetry.io/otel/sdk v1.11.2/go.mod h1:wZ1WxImwpq+lVRo4vsmSOxdd+xwoUJ6rqyLc3SyX9aU=
+go.opentelemetry.io/otel/trace v1.11.2 h1:Xf7hWSF2Glv0DE3MH7fBHvtpSBsjcBUe5MYAmZM/+y0=
+go.opentelemetry.io/otel/trace v1.11.2/go.mod h1:4N+yC7QEz7TTsG9BSRLNAa63eg5E06ObSbKPmxQ/pKA=
+golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8 h1:h+EGohizhe9XlX18rfpa8k8RAc5XyaeamM+0VHRd4lc=
+golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

sampler/coralogix-sampler.go

@@ -0,0 +1,87 @@
+package sampler
+
+import (
+	"context"
+	"go.opentelemetry.io/otel/attribute"
+	traceSdk "go.opentelemetry.io/otel/sdk/trace"
+	traceCore "go.opentelemetry.io/otel/trace"
+)
+
+const (
+	TransactionIdentifier                      = "cgx.transaction"
+	TransactionIdentifierTraceState            = "cgx_transaction"
+	DistributedTransactionIdentifier           = "cgx.transaction.distributed"
+	DistributedTransactionIdentifierTraceState = "cgx_transaction_distributed"
+)
+
+type CoralogixSampler struct {
+	adaptedSampler traceSdk.Sampler
+}
+
+func NewCoralogixSampler(adaptedSampler traceSdk.Sampler) *CoralogixSampler {
+	if adaptedSampler == nil {
+		panic("sampler is null")
+	}
+	return &CoralogixSampler{
+		adaptedSampler: adaptedSampler,
+	}
+}
+
+func (s *CoralogixSampler) ShouldSample(parameters traceSdk.SamplingParameters) traceSdk.SamplingResult {
+	adaptedSamplingResult := s.adaptedSampler.ShouldSample(parameters)
+
+	return s.generateTransactionSamplingResult(parameters.ParentContext, parameters.Name, adaptedSamplingResult)
+}
+
+func (s *CoralogixSampler) generateTransactionSamplingResult(ctx context.Context, name string, adaptedSamplingResult traceSdk.SamplingResult) traceSdk.SamplingResult {
+	newTracingState := s.generateNewTraceState(ctx, name, adaptedSamplingResult)
+	newAttributes := s.injectAttributes(adaptedSamplingResult, newTracingState)
+	return traceSdk.SamplingResult{
+		Decision:   adaptedSamplingResult.Decision,
+		Attributes: newAttributes,
+		Tracestate: newTracingState,
+	}
+}
+
+func (s *CoralogixSampler) injectAttributes(adaptedSamplingResult traceSdk.SamplingResult, newTracingState traceCore.TraceState) []attribute.KeyValue {
+	sampledAttributes := adaptedSamplingResult.Attributes
+
+	transactionIdentifier := attribute.String(TransactionIdentifier, newTracingState.Get(TransactionIdentifierTraceState))
+	distributedTransactionIdentifier := attribute.String(DistributedTransactionIdentifier, newTracingState.Get(DistributedTransactionIdentifierTraceState))
+
+	return append(sampledAttributes, transactionIdentifier, distributedTransactionIdentifier)
+}
+
+func (s *CoralogixSampler) getDescription() string {
+	return "coralogix-sampler"
+}
+
+func (s *CoralogixSampler) generateNewTraceState(ctx context.Context, name string, samplingResult traceSdk.SamplingResult) traceCore.TraceState {
+	parentSpanContext := s.getParentSpanContext(ctx)
+	parentTraceState := samplingResult.Tracestate
+
+	if !parentSpanContext.IsRemote() && parentTraceState.Get(TransactionIdentifierTraceState) != "" {
+		return parentTraceState
+	}
+
+	parentTraceState, err := parentTraceState.Insert(TransactionIdentifierTraceState, name)
+	if err != nil {
+		return parentTraceState
+	}
+	if parentTraceState.Get(DistributedTransactionIdentifierTraceState) == "" {
+		parentTraceState, err = parentTraceState.Insert(DistributedTransactionIdentifierTraceState, name)
+		if err != nil {
+			return parentTraceState
+		}
+	}
+
+	return parentTraceState
+}
+
+func (s *CoralogixSampler) getParentSpanContext(ctx context.Context) traceCore.SpanContext {
+	span := traceCore.SpanFromContext(ctx)
+	if span != nil {
+		return span.SpanContext()
+	}
+	return traceCore.SpanContext{}
+}

sampler/coralogix-sampler_test.go

@@ -0,0 +1,194 @@
+package sampler
+
+import (
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/otel/attribute"
+	traceSdk "go.opentelemetry.io/otel/sdk/trace"
+	"testing"
+)
+
+import (
+	"context"
+	traceCore "go.opentelemetry.io/otel/trace"
+)
+
+const (
+	spanName = "spanName"
+)
+
+func TestCoralogixSampler_ShouldSample(t *testing.T) {
+	t.Run("When_alwaysSampler_Should_AppendAttributesAndState", func(t *testing.T) {
+		alwaysSampler := traceSdk.AlwaysSample()
+		coralogixSampler := NewCoralogixSampler(alwaysSampler)
+
+		// Act
+		parameters := traceSdk.SamplingParameters{
+			ParentContext: context.Background(),
+			Name:          spanName,
+			Attributes:    []attribute.KeyValue{},
+		}
+		result := coralogixSampler.ShouldSample(parameters)
+
+		expectedAttributes := []attribute.KeyValue{
+			attribute.String(TransactionIdentifier, spanName),
+			attribute.String(DistributedTransactionIdentifier, spanName),
+		}
+
+		expectedTraceState := traceCore.TraceState{}
+
+		expectedTraceState, _ = expectedTraceState.Insert(TransactionIdentifierTraceState, spanName)
+		expectedTraceState, _ = expectedTraceState.Insert(DistributedTransactionIdentifierTraceState, spanName)
+
+		assert.Equal(t, traceSdk.RecordAndSample, result.Decision)
+		assert.ElementsMatch(t, expectedAttributes, result.Attributes)
+		assert.Equal(t, expectedTraceState, result.Tracestate)
+	})
+
+	t.Run("When_NeverSample_Should_AppendAttributesAndState", func(t *testing.T) {
+		neverSampler := traceSdk.NeverSample()
+		coralogixSampler := NewCoralogixSampler(neverSampler)
+
+		// Act
+		parameters := traceSdk.SamplingParameters{
+			ParentContext: context.Background(),
+			Name:          spanName,
+			Attributes:    []attribute.KeyValue{},
+		}
+		result := coralogixSampler.ShouldSample(parameters)
+
+		expectedAttributes := []attribute.KeyValue{
+			attribute.String(TransactionIdentifier, spanName),
+			attribute.String(DistributedTransactionIdentifier, spanName),
+		}
+
+		expectedTraceState := traceCore.TraceState{}
+
+		expectedTraceState, _ = expectedTraceState.Insert(TransactionIdentifierTraceState, spanName)
+		expectedTraceState, _ = expectedTraceState.Insert(DistributedTransactionIdentifierTraceState, spanName)
+
+		assert.Equal(t, traceSdk.Drop, result.Decision)
+		assert.ElementsMatch(t, expectedAttributes, result.Attributes)
+		assert.Equal(t, expectedTraceState, result.Tracestate)
+	})
+
+	t.Run("When_CustomSamplerIsNull_ShouldFailInit", func(t *testing.T) {
+		assert.Panics(t, func() {
+			_ = NewCoralogixSampler(nil)
+		})
+	})
+
+	t.Run("When_ParentContextExistsAndNotRemote_ShouldCopyParentTraceState", func(t *testing.T) {
+		alwaysSampler := traceSdk.AlwaysSample()
+		coralogixSampler := NewCoralogixSampler(alwaysSampler)
+
+		traceState := traceCore.TraceState{}
+
+		traceState, _ = traceState.Insert(TransactionIdentifierTraceState, "fatherSpanName")
+		traceState, _ = traceState.Insert(DistributedTransactionIdentifierTraceState, "fatherSpanName")
+
+		parentSpan := traceCore.NewSpanContext(traceCore.SpanContextConfig{
+			TraceID:    traceCore.TraceID{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F},
+			SpanID:     traceCore.SpanID{0xFF, 0xFE, 0xFD, 0xFC, 0xFB, 0xFA, 0xF9, 0xF8},
+			TraceFlags: traceCore.FlagsSampled,
+			TraceState: traceState,
+			Remote:     false,
+		})
+		parentCtx := traceCore.ContextWithSpanContext(context.Background(), parentSpan)
+
+		// Act
+		parameters := traceSdk.SamplingParameters{
+			ParentContext: parentCtx,
+			Name:          spanName,
+			Attributes:    []attribute.KeyValue{},
+		}
+		result := coralogixSampler.ShouldSample(parameters)
+
+		expectedAttributes := []attribute.KeyValue{
+			attribute.String(TransactionIdentifier, "fatherSpanName"),
+			attribute.String(DistributedTransactionIdentifier, "fatherSpanName"),
+		}
+		expectedTraceState := traceCore.TraceState{}
+		expectedTraceState, _ = traceState.Insert(TransactionIdentifierTraceState, "fatherSpanName")
+		expectedTraceState, _ = traceState.Insert(DistributedTransactionIdentifierTraceState, "fatherSpanName")
+
+		assert.ElementsMatch(t, expectedAttributes, result.Attributes)
+		assert.Equal(t, expectedTraceState, result.Tracestate)
+	})
+	t.Run("When_ParentContextExistsAndRemote_ShouldCopyParentTraceState", func(t *testing.T) {
+		alwaysSampler := traceSdk.AlwaysSample()
+		coralogixSampler := NewCoralogixSampler(alwaysSampler)
+
+		traceState := traceCore.TraceState{}
+
+		traceState, _ = traceState.Insert(TransactionIdentifierTraceState, "fatherSpanName")
+		traceState, _ = traceState.Insert(DistributedTransactionIdentifierTraceState, "fatherSpanName")
+
+		parentSpan := traceCore.NewSpanContext(traceCore.SpanContextConfig{
+			TraceID:    traceCore.TraceID{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F},
+			SpanID:     traceCore.SpanID{0xFF, 0xFE, 0xFD, 0xFC, 0xFB, 0xFA, 0xF9, 0xF8},
+			TraceFlags: traceCore.FlagsSampled,
+			TraceState: traceState,
+			Remote:     true,
+		})
+		parentCtx := traceCore.ContextWithSpanContext(context.Background(), parentSpan)
+
+		// Act
+		parameters := traceSdk.SamplingParameters{
+			ParentContext: parentCtx,
+			Name:          spanName,
+			Attributes:    []attribute.KeyValue{},
+		}
+		result := coralogixSampler.ShouldSample(parameters)
+
+		expectedAttributes := []attribute.KeyValue{
+			attribute.String(TransactionIdentifier, "spanName"),
+			attribute.String(DistributedTransactionIdentifier, "fatherSpanName"),
+		}
+		expectedTraceState := traceCore.TraceState{}
+		expectedTraceState, _ = expectedTraceState.Insert(TransactionIdentifierTraceState, spanName)
+		expectedTraceState, _ = expectedTraceState.Insert(DistributedTransactionIdentifierTraceState, "fatherSpanName")
+
+		assert.ElementsMatch(t, expectedAttributes, result.Attributes)
+		assert.Equal(t, expectedTraceState.Get(TransactionIdentifierTraceState), result.Tracestate.Get(TransactionIdentifierTraceState))
+		assert.Equal(t, expectedTraceState.Get(DistributedTransactionIdentifierTraceState), result.Tracestate.Get(DistributedTransactionIdentifierTraceState))
+	})
+
+	t.Run("When_ParentContextExistsAndRemote_ShouldCopyParentTraceState", func(t *testing.T) {
+		alwaysSampler := traceSdk.AlwaysSample()
+		coralogixSampler := NewCoralogixSampler(alwaysSampler)
+
+		traceState := traceCore.TraceState{}
+
+		traceState, _ = traceState.Insert(TransactionIdentifierTraceState, "fatherSpanName")
+		traceState, _ = traceState.Insert(DistributedTransactionIdentifierTraceState, "fatherSpanName")
+
+		parentSpan := traceCore.NewSpanContext(traceCore.SpanContextConfig{
+			TraceID:    traceCore.TraceID{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F},
+			SpanID:     traceCore.SpanID{0xFF, 0xFE, 0xFD, 0xFC, 0xFB, 0xFA, 0xF9, 0xF8},
+			TraceFlags: traceCore.FlagsSampled,
+			TraceState: traceState,
+			Remote:     true,
+		})
+		parentCtx := traceCore.ContextWithSpanContext(context.Background(), parentSpan)
+
+		// Act
+		parameters := traceSdk.SamplingParameters{
+			ParentContext: parentCtx,
+			Name:          spanName,
+			Attributes:    []attribute.KeyValue{},
+		}
+		result := coralogixSampler.ShouldSample(parameters)
+
+		expectedAttributes := []attribute.KeyValue{
+			attribute.String(TransactionIdentifier, "spanName"),
+			attribute.String(DistributedTransactionIdentifier, "fatherSpanName"),
+		}
+		expectedTraceState := traceCore.TraceState{}
+		expectedTraceState, _ = expectedTraceState.Insert(TransactionIdentifierTraceState, spanName)
+		expectedTraceState, _ = expectedTraceState.Insert(DistributedTransactionIdentifierTraceState, "fatherSpanName")
+
+		assert.ElementsMatch(t, expectedAttributes, result.Attributes)
+		assert.Equal(t, expectedTraceState.Get(TransactionIdentifierTraceState), result.Tracestate.Get(TransactionIdentifierTraceState))
+		assert.Equal(t, expectedTraceState.Get(DistributedTransactionIdentifierTraceState), result.Tracestate.Get(DistributedTransactionIdentifierTraceState))
+	})
+}