implement grpc gateway and addl handler support

pkg/app/run_http.go

@@ -0,0 +1,19 @@
+package app
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+)
+
+func (a *App) runHTTP(ctx context.Context) {
+	span := trace.SpanFromContext(ctx)
+	if err := a.initHTTP(ctx); err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
+	}
+	span.AddEvent("http server started")
+	span.SetAttributes(attribute.Int("http.handlers", len(a.HTTP.Funcs)))
+}