Merge pull request #9 from remychantenay/minor-improvements

Minor improvements

go.mod

@@ -3,14 +3,14 @@ module github.com/remychantenay/slog-otel
 go 1.21
 
 require (
-	go.opentelemetry.io/otel v1.19.0
-	go.opentelemetry.io/otel/sdk v1.19.0
-	go.opentelemetry.io/otel/trace v1.19.0
+	go.opentelemetry.io/otel v1.21.0
+	go.opentelemetry.io/otel/sdk v1.21.0
+	go.opentelemetry.io/otel/trace v1.21.0
 )
 
 require (
-	github.com/go-logr/logr v1.2.4 // indirect
+	github.com/go-logr/logr v1.3.0 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
-	go.opentelemetry.io/otel/metric v1.19.0 // indirect
-	golang.org/x/sys v0.12.0 // indirect
+	go.opentelemetry.io/otel/metric v1.21.0 // indirect
+	golang.org/x/sys v0.14.0 // indirect
 )

go.sum

@@ -1,25 +1,25 @@
 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 v1.2.4 h1:g01GSCwiDw2xSZfjJ2/T9M+S6pFdcNtFYsp+Y43HYDQ=
-github.com/go-logr/logr v1.2.4/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.3.0 h1:2y3SDp0ZXuc6/cjLSZ+Q3ir+QB9T/iG5yYRXqsagWSY=
+github.com/go-logr/logr v1.3.0/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
 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/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/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/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
-go.opentelemetry.io/otel v1.19.0 h1:MuS/TNf4/j4IXsZuJegVzI1cwut7Qc00344rgH7p8bs=
-go.opentelemetry.io/otel v1.19.0/go.mod h1:i0QyjOq3UPoTzff0PJB2N66fb4S0+rSbSB15/oyH9fY=
-go.opentelemetry.io/otel/metric v1.19.0 h1:aTzpGtV0ar9wlV4Sna9sdJyII5jTVJEvKETPiOKwvpE=
-go.opentelemetry.io/otel/metric v1.19.0/go.mod h1:L5rUsV9kM1IxCj1MmSdS+JQAcVm319EUrDVLrt7jqt8=
-go.opentelemetry.io/otel/sdk v1.19.0 h1:6USY6zH+L8uMH8L3t1enZPR3WFEmSTADlqldyHtJi3o=
-go.opentelemetry.io/otel/sdk v1.19.0/go.mod h1:NedEbbS4w3C6zElbLdPJKOpJQOrGUJ+GfzpjUvI0v1A=
-go.opentelemetry.io/otel/trace v1.19.0 h1:DFVQmlVbfVeOuBRrwdtaehRrWiL1JoVs9CPIQ1Dzxpg=
-go.opentelemetry.io/otel/trace v1.19.0/go.mod h1:mfaSyvGyEJEI0nyV2I4qhNQnbBOUUmYZpYojqMnX2vo=
-golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
-golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+go.opentelemetry.io/otel v1.21.0 h1:hzLeKBZEL7Okw2mGzZ0cc4k/A7Fta0uoPgaJCr8fsFc=
+go.opentelemetry.io/otel v1.21.0/go.mod h1:QZzNPQPm1zLX4gZK4cMi+71eaorMSGT3A4znnUvNNEo=
+go.opentelemetry.io/otel/metric v1.21.0 h1:tlYWfeo+Bocx5kLEloTjbcDwBuELRrIFxwdQ36PlJu4=
+go.opentelemetry.io/otel/metric v1.21.0/go.mod h1:o1p3CA8nNHW8j5yuQLdc1eeqEaPfzug24uvsyIEJRWM=
+go.opentelemetry.io/otel/sdk v1.21.0 h1:FTt8qirL1EysG6sTQRZ5TokkU8d0ugCj8htOgThZXQ8=
+go.opentelemetry.io/otel/sdk v1.21.0/go.mod h1:Nna6Yv7PWTdgJHVRD9hIYywQBRx7pbox6nwBnZIxl/E=
+go.opentelemetry.io/otel/trace v1.21.0 h1:WD9i5gzvoUPuXIXH24ZNBudiarZDKuekPqi/E8fpfLc=
+go.opentelemetry.io/otel/trace v1.21.0/go.mod h1:LGbsEB0f9LGjN+OZaQQ26sohbOmiMR+BaslueVtS/qQ=
+golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
+golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

slog_otel.go

@@ -12,6 +12,18 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
+const (
+	// TraceIDKey is the key used by the Otel handler
+	// to inject the trace ID in the log record.
+	TraceIDKey = "trace_id"
+	// SpanIDKey is the key used by the Otel handler
+	// to inject the span ID in the log record.
+	SpanIDKey = "span_id"
+	// SpanEventKey is the key used by the Otel handler
+	// to inject the log record in the recording span, as a span event.
+	SpanEventKey = "log_record"
+)
+
 // OtelHandler is an implementation of slog's Handler interface.
 // Its role is to ensure correlation between logs and OTel spans
 // by:
@@ -60,10 +72,10 @@ func (h OtelHandler) Handle(ctx context.Context, record slog.Record) error {
 	}
 
 	// Adding log info to span event.
-	eventAttrs := make([]attribute.KeyValue, 0)
-	eventAttrs = append(eventAttrs, attribute.String("msg", record.Message))
-	eventAttrs = append(eventAttrs, attribute.String("level", record.Level.String()))
-	eventAttrs = append(eventAttrs, attribute.String("time", record.Time.Format(time.RFC3339Nano)))
+	eventAttrs := make([]attribute.KeyValue, 0, record.NumAttrs())
+	eventAttrs = append(eventAttrs, attribute.String(slog.MessageKey, record.Message))
+	eventAttrs = append(eventAttrs, attribute.String(slog.LevelKey, record.Level.String()))
+	eventAttrs = append(eventAttrs, attribute.String(slog.TimeKey, record.Time.Format(time.RFC3339Nano)))
 
 	record.Attrs(func(attr slog.Attr) bool {
 		otelAttr := h.slogAttrToOtelAttr(attr)
@@ -74,18 +86,18 @@ func (h OtelHandler) Handle(ctx context.Context, record slog.Record) error {
 		return true
 	})
 
-	span.AddEvent("log_record", trace.WithAttributes(eventAttrs...))
+	span.AddEvent(SpanEventKey, trace.WithAttributes(eventAttrs...))
 
 	// Adding span info to log record.
 	spanContext := span.SpanContext()
 	if spanContext.HasTraceID() {
 		traceID := spanContext.TraceID().String()
-		record.AddAttrs(slog.String("trace_id", traceID))
+		record.AddAttrs(slog.String(TraceIDKey, traceID))
 	}
 
 	if spanContext.HasSpanID() {
 		spanID := spanContext.SpanID().String()
-		record.AddAttrs(slog.String("span_id", spanID))
+		record.AddAttrs(slog.String(SpanIDKey, spanID))
 	}
 
 	// Setting span status if the log is an error.