Add origin request count metrics in api (#1479)

api/internal/metrics/metrics.go

@@ -4,4 +4,5 @@ const serviceName = "wormscan-api"
 
 type Metrics interface {
 	IncExpiredCacheResponse(key string)
+	IncOrigin(origin, method, path string)
 }

api/internal/metrics/prometheus.go

@@ -8,22 +8,35 @@ import (
 // PrometheusMetrics is a Prometheus implementation of Metric interface.
 type PrometheusMetrics struct {
 	expiredCacheResponseCount *prometheus.CounterVec
+	originRequestsCount       *prometheus.CounterVec
 }
 
 // NewPrometheusMetrics returns a new instance of PrometheusMetrics.
 func NewPrometheusMetrics(environment string) *PrometheusMetrics {
+	constLabels := map[string]string{
+		"environment": environment,
+		"service":     serviceName,
+	}
+
 	vaaTxTrackerCount := promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name:        "expired_cache_response",
 			Help:        "Total expired cache response by key",
-			ConstLabels: map[string]string{
-				"environment": environment,
-				"service":     serviceName,
-			},
+			ConstLabels: constLabels,
 		}, []string{"key"})
 
+	originRequestsCount := promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:        "http_requests_origin_requests_total",
+			Help:        "Count all http requests by origin, method and path.",
+			ConstLabels: constLabels,
+		},
+		[]string{"origin", "method", "path"},
+	)
+
 	return &PrometheusMetrics{
 		expiredCacheResponseCount: vaaTxTrackerCount,
+		originRequestsCount:       originRequestsCount,
 	}
 }
 
@@ -31,10 +44,15 @@ func (m *PrometheusMetrics) IncExpiredCacheResponse(key string) {
 	m.expiredCacheResponseCount.WithLabelValues(key).Inc()
 }
 
+func (m *PrometheusMetrics) IncOrigin(origin, method, path string) {
+	m.originRequestsCount.WithLabelValues(origin, method, path).Inc()
+}
+
 type noOpMetrics struct{}
 
-func (s *noOpMetrics) IncExpiredCacheResponse(_ string) {
-}
+func (s *noOpMetrics) IncExpiredCacheResponse(_ string) {}
+
+func (s *noOpMetrics) IncOrigin(_, _, _ string) {}
 
 func NewNoOpMetrics() Metrics {
 	return &noOpMetrics{}

api/main.go

@@ -197,16 +197,13 @@ func main() {
 	prometheus := fiberprometheus.NewWithLabels(labels, "http", "")
 	prometheus.RegisterAt(app, "/metrics")
 	app.Use(prometheus.Middleware)
+	app.Use(middleware.OriginMetrics(metrics))
 
 	app.Use(requestid.New())
 	app.Use(logger.New(logger.Config{
 		Format: "level=info timestamp=${time} method=${method} path=${path} latency=${latency} status${status} request_id=${locals:requestid} ip=${ips} queryParams=${queryParams}\n",
 		Next: func(c *fiber.Ctx) bool {
-			path := c.Path()
-			if path == "/api/v1/health" || path == "/api/v1/ready" {
-				return true
-			}
-			return false
+			return middleware.IsK8sPath(c.Path())
 		},
 	}))
 	if cfg.PprofEnabled {

api/middleware/k8s.go

@@ -0,0 +1,8 @@
+package middleware
+
+func IsK8sPath(path string) bool {
+	if path == "/api/v1/health" || path == "/api/v1/ready" {
+		return true
+	}
+	return false
+}

api/middleware/origin_metrics.go

@@ -0,0 +1,26 @@
+// package middleare contains all the middleware function to use in the API.
+package middleware
+
+import (
+	"strings"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/metrics"
+)
+
+// ExtractPagination parses pagination-related query parameters.
+func OriginMetrics(m metrics.Metrics) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		err := c.Next()
+		path := c.Route().Path
+		if !IsK8sPath(path) {
+			method := c.Route().Method
+			originHeader := strings.ToLower(c.Get(fiber.HeaderOrigin))
+			if originHeader == "" {
+				originHeader = "unknown"
+			}
+			m.IncOrigin(originHeader, method, path)
+		}
+		return err
+	}
+}