tech(metrics): move all request counters into one middleware

pkg/middleware/request_metrics.go

@@ -0,0 +1,38 @@
+package middleware
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/grafana/grafana/pkg/metrics"
+	"gopkg.in/macaron.v1"
+)
+
+func RequestMetrics() macaron.Handler {
+	return func(res http.ResponseWriter, req *http.Request, c *macaron.Context) {
+		rw := res.(macaron.ResponseWriter)
+		c.Next()
+
+		status := rw.Status()
+
+		if strings.HasPrefix(req.URL.Path, "/api/") {
+			switch status {
+			case 200:
+				metrics.M_Api_Status_200.Inc(1)
+			case 404:
+				metrics.M_Api_Status_404.Inc(1)
+			case 500:
+				metrics.M_Api_Status_500.Inc(1)
+			}
+		} else {
+			switch status {
+			case 200:
+				metrics.M_Page_Status_200.Inc(1)
+			case 404:
+				metrics.M_Page_Status_404.Inc(1)
+			case 500:
+				metrics.M_Page_Status_500.Inc(1)
+			}
+		}
+	}
+}