feat: 完善后端脚手架基础能力

middlewares/metrics.go

@@ -0,0 +1,39 @@
+package middlewares
+
+import (
+	"strconv"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	httpRequests = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Name: "skeleton_http_requests_total",
+		Help: "Total number of HTTP requests.",
+	}, []string{"method", "route", "status"})
+	httpDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Name:    "skeleton_http_request_duration_seconds",
+		Help:    "HTTP request latency in seconds.",
+		Buckets: prometheus.DefBuckets,
+	}, []string{"method", "route", "status"})
+)
+
+func init() {
+	prometheus.MustRegister(httpRequests, httpDuration)
+}
+
+func Metrics() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		started := time.Now()
+		c.Next()
+		route := c.FullPath()
+		if route == "" {
+			route = "unmatched"
+		}
+		status := strconv.Itoa(c.Writer.Status())
+		httpRequests.WithLabelValues(c.Request.Method, route, status).Inc()
+		httpDuration.WithLabelValues(c.Request.Method, route, status).Observe(time.Since(started).Seconds())
+	}
+}