Add OpenTelemetry tracing and log correlation

infrastructure/observability/logger.go

@@ -1,8 +1,11 @@
 package observability
 
 import (
+	"context"
 	"log/slog"
 	"os"
+
+	"go.opentelemetry.io/otel/trace"
 )
 
 // Configure installs the process-wide JSON logger used by every GL adapter.
@@ -24,7 +27,24 @@ func Configure(service string, level slog.Leveler) *slog.Logger {
 			return attr
 		},
 	})
-	logger := slog.New(handler).With("service", service)
+	logger := slog.New(&traceHandler{Handler: handler}).With("service", service)
 	slog.SetDefault(logger)
 	return logger
 }
+
+type traceHandler struct{ slog.Handler }
+
+func (h *traceHandler) Handle(ctx context.Context, record slog.Record) error {
+	spanContext := trace.SpanContextFromContext(ctx)
+	if spanContext.IsValid() {
+		record.AddAttrs(slog.String("trace_id", spanContext.TraceID().String()), slog.String("span_id", spanContext.SpanID().String()))
+	}
+	return h.Handler.Handle(ctx, record)
+}
+
+func (h *traceHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+	return &traceHandler{Handler: h.Handler.WithAttrs(attrs)}
+}
+func (h *traceHandler) WithGroup(name string) slog.Handler {
+	return &traceHandler{Handler: h.Handler.WithGroup(name)}
+}