feat(libreoffice): add conversion size and requested pdf-format span attributes

pkg/modules/libreoffice/api/api.go

@@ -626,6 +626,7 @@ func (a *Api) Pdf(ctx context.Context, logger *slog.Logger, inputPath, outputPat
 		attribute.Int64("gotenberg.queue.depth_at_arrival", a.supervisor.ReqQueueSize()),
 		attribute.Int64("gotenberg.conversions_since_last_restart", a.supervisor.ConversionsSinceRestart()),
 	)
+	span.SetAttributes(conversionRequestAttributes(inputPath, options)...)
 
 	start := time.Now()
 	var conversionStart time.Time
@@ -668,6 +669,7 @@ func (a *Api) Pdf(ctx context.Context, logger *slog.Logger, inputPath, outputPat
 		stat, statErr := os.Stat(outputPath)
 		if statErr == nil {
 			a.pdfOutputSizeCounter.Record(ctx, stat.Size(), attrs)
+			span.SetAttributes(attribute.Int64("gotenberg.conversion.output.bytes", stat.Size()))
 		}
 
 		span.SetStatus(codes.Ok, "")
@@ -685,6 +687,24 @@ func (a *Api) Pdf(ctx context.Context, logger *slog.Logger, inputPath, outputPat
 	return fmt.Errorf("supervisor run task: %w", err)
 }
 
+// conversionRequestAttributes derives low-cardinality attributes describing the
+// requested conversion: the input document size and the requested PDF format
+// options.
+func conversionRequestAttributes(inputPath string, options Options) []attribute.KeyValue {
+	attrs := []attribute.KeyValue{
+		attribute.String("gotenberg.libreoffice.pdf_a", options.PdfFormats.PdfA),
+		attribute.Bool("gotenberg.libreoffice.pdf_ua", options.PdfFormats.PdfUa),
+		attribute.Bool("gotenberg.conversion.landscape", options.Landscape),
+		attribute.Bool("gotenberg.conversion.has_page_ranges", options.PageRanges != ""),
+	}
+
+	if info, err := os.Stat(inputPath); err == nil {
+		attrs = append(attrs, attribute.Int64("gotenberg.conversion.input.bytes", info.Size()))
+	}
+
+	return attrs
+}
+
 // libreofficeErrorType maps a conversion error to LibreOffice's bounded reason
 // value, reused as the span error.type. Generic failures fall back to
 // [gotenberg.ClassifyError].

pkg/modules/libreoffice/api/api_request_attrs_test.go

@@ -0,0 +1,44 @@
+package api
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/gotenberg/gotenberg/v8/pkg/gotenberg"
+)
+
+func TestConversionRequestAttributes(t *testing.T) {
+	tmp := filepath.Join(t.TempDir(), "in.docx")
+	content := []byte("hello world")
+	if err := os.WriteFile(tmp, content, 0o600); err != nil {
+		t.Fatalf("write temp file: %v", err)
+	}
+
+	options := Options{
+		Landscape:  true,
+		PageRanges: "1-3",
+		PdfFormats: gotenberg.PdfFormats{PdfA: "PDF/A-2b", PdfUa: true},
+	}
+
+	got := map[string]any{}
+	for _, kv := range conversionRequestAttributes(tmp, options) {
+		got[string(kv.Key)] = kv.Value.AsInterface()
+	}
+
+	if got["gotenberg.libreoffice.pdf_a"] != "PDF/A-2b" {
+		t.Errorf("pdf_a = %v, want PDF/A-2b", got["gotenberg.libreoffice.pdf_a"])
+	}
+	if got["gotenberg.libreoffice.pdf_ua"] != true {
+		t.Errorf("pdf_ua = %v, want true", got["gotenberg.libreoffice.pdf_ua"])
+	}
+	if got["gotenberg.conversion.landscape"] != true {
+		t.Errorf("landscape = %v, want true", got["gotenberg.conversion.landscape"])
+	}
+	if got["gotenberg.conversion.has_page_ranges"] != true {
+		t.Errorf("has_page_ranges = %v, want true", got["gotenberg.conversion.has_page_ranges"])
+	}
+	if got["gotenberg.conversion.input.bytes"] != int64(len(content)) {
+		t.Errorf("input.bytes = %v, want %d", got["gotenberg.conversion.input.bytes"], len(content))
+	}
+}