add monitoring

metrics.go

@@ -0,0 +1,137 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var (
+	// HTTP request metrics
+	httpRequestsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "http_requests_total",
+			Help: "Total number of HTTP requests",
+		},
+		[]string{"method", "endpoint", "status_code"},
+	)
+
+	// HTTP request duration metrics
+	httpRequestDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "http_request_duration_seconds",
+			Help:    "HTTP request duration in seconds",
+			Buckets: prometheus.DefBuckets,
+		},
+		[]string{"method", "endpoint"},
+	)
+
+	// API endpoint specific metrics
+	apiRequestsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "api_requests_total",
+			Help: "Total number of API requests by endpoint",
+		},
+		[]string{"endpoint", "method"},
+	)
+
+	// Database operation metrics
+	dbOperationsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "db_operations_total",
+			Help: "Total number of database operations",
+		},
+		[]string{"operation", "table"},
+	)
+
+	// Authentication metrics
+	authAttemptsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "auth_attempts_total",
+			Help: "Total number of authentication attempts",
+		},
+		[]string{"type", "status"},
+	)
+)
+
+// InitMetrics initializes Prometheus metrics
+func InitMetrics() {
+	// Register all metrics
+	prometheus.MustRegister(httpRequestsTotal)
+	prometheus.MustRegister(httpRequestDuration)
+	prometheus.MustRegister(apiRequestsTotal)
+	prometheus.MustRegister(dbOperationsTotal)
+	prometheus.MustRegister(authAttemptsTotal)
+}
+
+// StartMetricsServer starts the metrics server on a separate port
+func StartMetricsServer(port string) {
+	// Create a new HTTP server for metrics
+	metricsMux := http.NewServeMux()
+	metricsMux.Handle("/metrics", promhttp.Handler())
+
+	// Add health check for metrics server
+	metricsMux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("Metrics server is healthy"))
+	})
+
+	server := &http.Server{
+		Addr:         "localhost:" + port,
+		Handler:      metricsMux,
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	}
+
+	go func() {
+		log.Printf("📈 Metrics server starting on http://localhost:%s/metrics", port)
+		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Printf("❌ Metrics server failed to start: %v", err)
+		}
+	}()
+}
+
+// MetricsMiddleware is a Gin middleware to collect HTTP metrics
+func MetricsMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		start := time.Now()
+		path := c.FullPath()
+		method := c.Request.Method
+
+		// Process request
+		c.Next()
+
+		// Calculate duration
+		duration := time.Since(start).Seconds()
+		statusCode := strconv.Itoa(c.Writer.Status())
+
+		// Record metrics
+		httpRequestsTotal.WithLabelValues(method, path, statusCode).Inc()
+		httpRequestDuration.WithLabelValues(method, path).Observe(duration)
+
+		// Record API-specific metrics for API routes
+		if c.Request.URL.Path[:4] == "/api" {
+			apiRequestsTotal.WithLabelValues(path, method).Inc()
+		}
+	}
+}
+
+// RecordAPICall records a specific API endpoint call
+func RecordAPICall(endpoint, method string) {
+	apiRequestsTotal.WithLabelValues(endpoint, method).Inc()
+}
+
+// RecordDBOperation records a database operation
+func RecordDBOperation(operation, table string) {
+	dbOperationsTotal.WithLabelValues(operation, table).Inc()
+}
+
+// RecordAuthAttempt records an authentication attempt
+func RecordAuthAttempt(authType, status string) {
+	authAttemptsTotal.WithLabelValues(authType, status).Inc()
+}