Billing docs improvement + build opt

api/billing/documents/internal/service/documents/metrics.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
-	documentsv1 "github.com/tech/sendico/pkg/proto/billing/documents/v1"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -17,7 +16,6 @@ var (
 
 	requestsTotal  *prometheus.CounterVec
 	requestLatency *prometheus.HistogramVec
-	batchSize      prometheus.Histogram
 	documentBytes  *prometheus.HistogramVec
 )
 
@@ -44,16 +42,6 @@ func initMetrics() {
 			[]string{"call", "status", "doc_type"},
 		)
 
-		batchSize = promauto.NewHistogram(
-			prometheus.HistogramOpts{
-				Namespace: "billing",
-				Subsystem: "documents",
-				Name:      "batch_size",
-				Help:      "Number of payment references in batch resolution requests.",
-				Buckets:   []float64{0, 1, 2, 5, 10, 20, 50, 100, 250, 500},
-			},
-		)
-
 		documentBytes = promauto.NewHistogramVec(
 			prometheus.HistogramOpts{
 				Namespace: "billing",
@@ -67,18 +55,14 @@ func initMetrics() {
 	})
 }
 
-func observeRequest(call string, docType documentsv1.DocumentType, statusLabel string, took time.Duration) {
-	typeLabel := docTypeLabel(docType)
-	requestsTotal.WithLabelValues(call, statusLabel, typeLabel).Inc()
-	requestLatency.WithLabelValues(call, statusLabel, typeLabel).Observe(took.Seconds())
+func observeRequest(call string, documentKind, statusLabel string, took time.Duration) {
+	kind := docKindLabel(documentKind)
+	requestsTotal.WithLabelValues(call, statusLabel, kind).Inc()
+	requestLatency.WithLabelValues(call, statusLabel, kind).Observe(took.Seconds())
 }
 
-func observeBatchSize(size int) {
-	batchSize.Observe(float64(size))
-}
-
-func observeDocumentBytes(docType documentsv1.DocumentType, size int) {
-	documentBytes.WithLabelValues(docTypeLabel(docType)).Observe(float64(size))
+func observeDocumentBytes(documentKind string, size int) {
+	documentBytes.WithLabelValues(docKindLabel(documentKind)).Observe(float64(size))
 }
 
 func statusFromError(err error) string {
@@ -100,10 +84,10 @@ func statusFromError(err error) string {
 	return strings.ToLower(code.String())
 }
 
-func docTypeLabel(docType documentsv1.DocumentType) string {
-	label := docType.String()
+func docKindLabel(documentKind string) string {
+	label := strings.TrimSpace(documentKind)
 	if label == "" {
-		return "DOCUMENT_TYPE_UNSPECIFIED"
+		return "operation"
 	}
 
 	return label