Merge pull request #138 from instana/correlation_id_support

Support EUM script correlation

instrumentation_http_test.go

@@ -39,6 +39,8 @@ func TestTracingHandlerFunc_Write(t *testing.T) {
 	assert.Equal(t, 0, span.Ec)
 	assert.EqualValues(t, instana.EntrySpanKind, span.Kind)
 	assert.False(t, span.Synthetic)
+	assert.Empty(t, span.CorrelationType)
+	assert.Empty(t, span.CorrelationID)
 
 	assert.Nil(t, span.ForeignParent)
 
@@ -214,6 +216,29 @@ func TestTracingHandlerFunc_SyntheticCall(t *testing.T) {
 	assert.True(t, spans[0].Synthetic)
 }
 
+func TestTracingHandlerFunc_EUMCall(t *testing.T) {
+	recorder := instana.NewTestRecorder()
+	s := instana.NewSensorWithTracer(instana.NewTracerWithEverything(&instana.Options{}, recorder))
+
+	h := instana.TracingHandlerFunc(s, "test-handler", func(w http.ResponseWriter, req *http.Request) {
+		fmt.Fprintln(w, "Ok")
+	})
+
+	rec := httptest.NewRecorder()
+
+	req := httptest.NewRequest(http.MethodGet, "/test", nil)
+	req.Header.Set(instana.FieldL, "1,correlationType=web;correlationId=eum correlation id")
+
+	h.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+
+	spans := recorder.GetQueuedSpans()
+	require.Len(t, spans, 1)
+	assert.Equal(t, "web", spans[0].CorrelationType)
+	assert.Equal(t, "eum correlation id", spans[0].CorrelationID)
+}
+
 func TestTracingHandlerFunc_PanicHandling(t *testing.T) {
 	recorder := instana.NewTestRecorder()
 	s := instana.NewSensorWithTracer(instana.NewTracerWithEverything(&instana.Options{}, recorder))

json_span.go

@@ -111,34 +111,38 @@ func newW3CForeignParent(trCtx w3ctrace.Context) *ForeignParent {
 
 // Span represents the OpenTracing span document to be sent to the agent
 type Span struct {
-	TraceID       int64          `json:"t"`
-	ParentID      int64          `json:"p,omitempty"`
-	SpanID        int64          `json:"s"`
-	Timestamp     uint64         `json:"ts"`
-	Duration      uint64         `json:"d"`
-	Name          string         `json:"n"`
-	From          *fromS         `json:"f"`
-	Batch         *batchInfo     `json:"b,omitempty"`
-	Kind          int            `json:"k"`
-	Ec            int            `json:"ec,omitempty"`
-	Data          typedSpanData  `json:"data"`
-	Synthetic     bool           `json:"sy,omitempty"`
-	ForeignParent *ForeignParent `json:"fp,omitempty"`
+	TraceID         int64          `json:"t"`
+	ParentID        int64          `json:"p,omitempty"`
+	SpanID          int64          `json:"s"`
+	Timestamp       uint64         `json:"ts"`
+	Duration        uint64         `json:"d"`
+	Name            string         `json:"n"`
+	From            *fromS         `json:"f"`
+	Batch           *batchInfo     `json:"b,omitempty"`
+	Kind            int            `json:"k"`
+	Ec              int            `json:"ec,omitempty"`
+	Data            typedSpanData  `json:"data"`
+	Synthetic       bool           `json:"sy,omitempty"`
+	ForeignParent   *ForeignParent `json:"fp,omitempty"`
+	CorrelationType string         `json:"crtp,omitempty"`
+	CorrelationID   string         `json:"crid,omitempty"`
 }
 
 func newSpan(span *spanS) Span {
 	data := RegisteredSpanType(span.Operation).ExtractData(span)
 	sp := Span{
-		TraceID:       span.context.TraceID,
-		ParentID:      span.context.ParentID,
-		SpanID:        span.context.SpanID,
-		Timestamp:     uint64(span.Start.UnixNano()) / uint64(time.Millisecond),
-		Duration:      uint64(span.Duration) / uint64(time.Millisecond),
-		Name:          string(data.Type()),
-		Ec:            span.ErrorCount,
-		ForeignParent: newForeignParent(span.context.ForeignParent),
-		Kind:          int(data.Kind()),
-		Data:          data,
+		TraceID:         span.context.TraceID,
+		ParentID:        span.context.ParentID,
+		SpanID:          span.context.SpanID,
+		Timestamp:       uint64(span.Start.UnixNano()) / uint64(time.Millisecond),
+		Duration:        uint64(span.Duration) / uint64(time.Millisecond),
+		Name:            string(data.Type()),
+		Ec:              span.ErrorCount,
+		ForeignParent:   newForeignParent(span.context.ForeignParent),
+		CorrelationType: span.Correlation.Type,
+		CorrelationID:   span.Correlation.ID,
+		Kind:            int(data.Kind()),
+		Data:            data,
 	}
 
 	if bs, ok := span.Tags[batchSizeTag].(int); ok {

propagation.go

@@ -1,6 +1,7 @@
 package instana
 
 import (
+	"errors"
 	"net/http"
 	"strings"
 
@@ -113,7 +114,16 @@ func extractTraceContext(opaqueCarrier interface{}) (SpanContext, error) {
 		case FieldS:
 			spanID = v
 		case FieldL:
-			spanContext.Suppressed = parseLevel(v)
+			suppressed, corrData, err := parseLevel(v)
+			if err != nil {
+				sensor.logger.Info("failed to parse %s: %s %q", k, err, v)
+				// use defaults
+				suppressed, corrData = false, EUMCorrelationData{}
+			}
+			spanContext.Suppressed = suppressed
+			if !spanContext.Suppressed {
+				spanContext.Correlation = corrData
+			}
 		default:
 			if strings.HasPrefix(strings.ToLower(k), FieldB) {
 				// preserve original case of the baggage key
@@ -127,6 +137,11 @@ func extractTraceContext(opaqueCarrier interface{}) (SpanContext, error) {
 		return spanContext, err
 	}
 
+	// For compatibility reasons X-Instana-{T,S} values if EUM has provided correlation ID
+	if spanContext.Correlation.ID != "" {
+		return spanContext, nil
+	}
+
 	if traceID == "" && spanID == "" {
 		if spanContext.W3CContext.IsZero() {
 			return spanContext, ot.ErrSpanContextNotFound
@@ -197,8 +212,88 @@ func addEUMHeaders(h http.Header, sc SpanContext) {
 	h.Set("Server-Timing", strings.Join(st, ", "))
 }
 
-func parseLevel(s string) bool {
-	return s == "0"
+var errMalformedHeader = errors.New("malformed header value")
+
+func parseLevel(s string) (bool, EUMCorrelationData, error) {
+	const (
+		levelState uint8 = iota
+		partSeparatorState
+		correlationPartState
+		correlationTypeState
+		correlationIDState
+		finalState
+	)
+
+	if s == "" {
+		return false, EUMCorrelationData{}, nil
+	}
+
+	var (
+		typeInd                 int
+		state                   uint8
+		level, corrType, corrID string
+	)
+PARSE:
+	for ptr := 0; state != finalState && ptr < len(s); ptr++ {
+		switch state {
+		case levelState: // looking for 0 or 1
+			level = s[ptr : ptr+1]
+
+			if level != "0" && level != "1" {
+				break PARSE
+			}
+
+			if ptr == len(s)-1 { // no correlation ID provided
+				state = finalState
+			} else {
+				state = partSeparatorState
+			}
+		case partSeparatorState: // skip OWS while looking for ','
+			switch s[ptr] {
+			case ' ', '\t': // advance
+			case ',':
+				state = correlationPartState
+			default:
+				break PARSE
+			}
+		case correlationPartState: // skip OWS while searching for 'correlationType=' prefix
+			switch {
+			case s[ptr] == ' ' || s[ptr] == '\t': // advance
+			case strings.HasPrefix(s[ptr:], "correlationType="):
+				ptr += 15 // advance to the end of prefix
+				typeInd = ptr + 1
+				state = correlationTypeState
+			default:
+				break PARSE
+			}
+		case correlationTypeState: // skip OWS while looking for ';'
+			switch s[ptr] {
+			case ' ', '\t': // possibly trailing OWS, advance
+			case ';':
+				state = correlationIDState
+			default:
+				corrType = s[typeInd : ptr+1]
+			}
+		case correlationIDState: //  skip OWS while searching for 'correlationId=' prefix
+			switch {
+			case s[ptr] == ' ' || s[ptr] == '\t': // leading OWS, advance
+			case strings.HasPrefix(s[ptr:], "correlationId="):
+				ptr += 14
+				corrID = s[ptr:]
+				state = finalState
+			default:
+				break PARSE
+			}
+		default:
+			break PARSE
+		}
+	}
+
+	if state != finalState {
+		return false, EUMCorrelationData{}, errMalformedHeader
+	}
+
+	return level == "0", EUMCorrelationData{Type: corrType, ID: corrID}, nil
 }
 
 func formatLevel(sc SpanContext) string {

propagation_internal_test.go

@@ -0,0 +1,49 @@
+package instana
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseLevel(t *testing.T) {
+	examples := map[string]struct {
+		Value               string
+		ExpectedSuppressed  bool
+		ExpectedCorrelation EUMCorrelationData
+	}{
+		"empty header": {},
+		"level=0, no correlation id": {
+			Value:              "0",
+			ExpectedSuppressed: true,
+		},
+		"level=1, no correlation id": {
+			Value: "1",
+		},
+		"level=0, with correlation id": {
+			Value:              "0   ,   correlationType=web  ;\t  correlationId=Test Value",
+			ExpectedSuppressed: true,
+			ExpectedCorrelation: EUMCorrelationData{
+				Type: "web",
+				ID:   "Test Value",
+			},
+		},
+		"level=1, with correlation id": {
+			Value: "1,correlationType=mobile;correlationId=Test Value",
+			ExpectedCorrelation: EUMCorrelationData{
+				Type: "mobile",
+				ID:   "Test Value",
+			},
+		},
+	}
+
+	for name, example := range examples {
+		t.Run(name, func(t *testing.T) {
+			suppressed, corrData, err := parseLevel(example.Value)
+			require.NoError(t, err)
+			assert.Equal(t, example.ExpectedSuppressed, suppressed)
+			assert.Equal(t, example.ExpectedCorrelation, corrData)
+		})
+	}
+}

propagation_test.go

@@ -301,6 +301,20 @@ func TestTracer_Extract_HTTPHeaders(t *testing.T) {
 				Baggage:    map[string]string{},
 			},
 		},
+		"tracing disabled, with correlation data": {
+			Headers: map[string]string{
+				"Authorization": "Basic 123",
+				"x-instana-t":   "1314",
+				"X-INSTANA-S":   "2435",
+				"X-Instana-L":   "0,correlationType=web;correlationId=1234",
+			},
+			Expected: instana.SpanContext{
+				TraceID:    0x1314,
+				SpanID:     0x2435,
+				Suppressed: true,
+				Baggage:    map[string]string{},
+			},
+		},
 		"w3c trace context, last vendor is instana": {
 			Headers: map[string]string{
 				"x-instana-t": "1314",
@@ -370,6 +384,48 @@ func TestTracer_Extract_HTTPHeaders(t *testing.T) {
 	}
 }
 
+func TestTracer_Extract_HTTPHeaders_WithEUMCorrelation(t *testing.T) {
+	examples := map[string]struct {
+		Headers  map[string]string
+		Expected instana.SpanContext
+	}{
+		"tracing enabled, no instana headers": {
+			Headers: map[string]string{
+				"X-Instana-L": "1,correlationType=web;correlationId=1234",
+			},
+		},
+		"tracing enabled, with instana headers": {
+			Headers: map[string]string{
+				"X-Instana-T": "0000000000002435",
+				"X-Instana-S": "0000000000003546",
+				"X-Instana-L": "1,correlationType=web;correlationId=1234",
+			},
+		},
+	}
+
+	for name, example := range examples {
+		t.Run(name, func(t *testing.T) {
+			recorder := instana.NewTestRecorder()
+			tracer := instana.NewTracerWithEverything(&instana.Options{}, recorder)
+
+			headers := http.Header{}
+			for k, v := range example.Headers {
+				headers.Set(k, v)
+			}
+
+			sc, err := tracer.Extract(ot.HTTPHeaders, ot.HTTPHeadersCarrier(headers))
+			require.NoError(t, err)
+
+			spanContext := sc.(instana.SpanContext)
+
+			assert.EqualValues(t, 0, spanContext.TraceID)
+			assert.EqualValues(t, 0, spanContext.SpanID)
+			assert.Empty(t, spanContext.ParentID)
+			assert.Equal(t, instana.EUMCorrelationData{ID: "1234", Type: "web"}, spanContext.Correlation)
+		})
+	}
+}
+
 func TestTracer_Extract_HTTPHeaders_NoContext(t *testing.T) {
 	examples := map[string]struct {
 		Headers  map[string]string

span.go

@@ -9,13 +9,14 @@ import (
 )
 
 type spanS struct {
-	Service    string
-	Operation  string
-	Start      time.Time
-	Duration   time.Duration
-	Tags       ot.Tags
-	Logs       []ot.LogRecord
-	ErrorCount int
+	Service     string
+	Operation   string
+	Start       time.Time
+	Duration    time.Duration
+	Correlation EUMCorrelationData
+	Tags        ot.Tags
+	Logs        []ot.LogRecord
+	ErrorCount  int
 
 	tracer *tracerS
 	mu     sync.Mutex

span_context.go

@@ -6,6 +6,13 @@ import (
 	"github.com/instana/go-sensor/w3ctrace"
 )
 
+// EUMCorrelationData represents the data sent by the Instana End-User Monitoring script
+// integrated into frontend
+type EUMCorrelationData struct {
+	Type string
+	ID   string
+}
+
 // SpanContext holds the basic Span metadata.
 type SpanContext struct {
 	// A probabilistically unique identifier for a [multi-span] trace.
@@ -22,6 +29,8 @@ type SpanContext struct {
 	Baggage map[string]string // initialized on first use
 	// The W3C trace context
 	W3CContext w3ctrace.Context
+	// Correlation is the correlation data sent by the frontend EUM script
+	Correlation EUMCorrelationData
 	// The 3rd party parent if the context is derived from non-Instana trace
 	ForeignParent interface{}
 }