feat: add metrics

.gitignore

@@ -12,3 +12,4 @@ NOTES.md
 tests
 configs
 /config
+compose.yaml

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/common-nighthawk/go-figure v0.0.0-20210622060536-734e95fb86be
 	github.com/golang-jwt/jwt v3.2.2+incompatible
 	github.com/gorilla/mux v1.8.1
+	github.com/prometheus/client_golang v1.20.5
 	github.com/spf13/cobra v1.8.1
 	golang.org/x/oauth2 v0.24.0
 	gopkg.in/yaml.v3 v3.0.1
@@ -20,7 +21,15 @@ require (
 
 require (
 	cloud.google.com/go/compute/metadata v0.3.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.55.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
 
 )

go.sum

@@ -1,5 +1,9 @@
 cloud.google.com/go/compute/metadata v0.3.0 h1:Tz+eQXMEqDIKRsmY3cHTL6FVaynIjX2QxYC4trgAKZc=
 cloud.google.com/go/compute/metadata v0.3.0/go.mod h1:zFmK7XCadkQkj6TtorcaGlCW1hT1fIilQDwofLpJ20k=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/common-nighthawk/go-figure v0.0.0-20210622060536-734e95fb86be h1:J5BL2kskAlV9ckgEsNQXscjIaLiOYiZ75d4e94E6dcQ=
 github.com/common-nighthawk/go-figure v0.0.0-20210622060536-734e95fb86be/go.mod h1:mk5IQ+Y0ZeO87b858TlA645sVcEcbiX6YqP98kt+7+w=
 github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
@@ -15,12 +19,24 @@ github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/jedib0t/go-pretty/v6 v6.6.1 h1:iJ65Xjb680rHcikRj6DSIbzCex2huitmc7bDtxYVWyc=
 github.com/jedib0t/go-pretty/v6 v6.6.1/go.mod h1:zbn98qrYlh95FIhwwsbIip0LYpwSG8SUOScs+v9/t0E=
+github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
 github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mattn/go-runewidth v0.0.16 h1:E5ScNMtiwvlvB5paMFdw9p4kSQzbXFikJ5SQO6TULQc=
 github.com/mattn/go-runewidth v0.0.16/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.20.5 h1:cxppBPuYhUnsO6yo/aoRol4L7q7UFfdm+bR9r+8l63Y=
+github.com/prometheus/client_golang v1.20.5/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
+github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
+github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
+github.com/prometheus/common v0.55.0 h1:KEi6DK7lXW/m7Ig5i47x0vRzuBsHuvJdi5ee6Y3G1dc=
+github.com/prometheus/common v0.55.0/go.mod h1:2SECS4xJG1kd8XF9IcM1gMX6510RAEL65zxzNImwdc8=
+github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
+github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
@@ -40,6 +56,8 @@ golang.org/x/sys v0.17.0 h1:25cE3gD+tdBA7lp7QfhuV+rJiE9YXTcS3VG1SqssI/Y=
 golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
 golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

internal/prometheus.go

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2024 Jonas Kaninda
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package pkg
+
+import (
+	"github.com/gorilla/mux"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"net/http"
+	"strconv"
+)
+
+type PrometheusRoute struct {
+	name string
+	path string
+}
+
+var totalRequests = prometheus.NewCounterVec(
+	prometheus.CounterOpts{
+		Name: "http_requests_total",
+		Help: "Number of get requests.",
+	},
+	[]string{"path"},
+)
+
+var responseStatus = prometheus.NewCounterVec(
+	prometheus.CounterOpts{
+		Name: "response_status",
+		Help: "Status of HTTP response",
+	},
+	[]string{"status"},
+)
+
+var httpDuration = promauto.NewHistogramVec(prometheus.HistogramOpts{
+	Name: "http_response_time_seconds",
+	Help: "Duration of HTTP requests.",
+}, []string{"path"})
+
+func prometheusMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		route := mux.CurrentRoute(r)
+		path, _ := route.GetPathTemplate()
+		timer := prometheus.NewTimer(httpDuration.WithLabelValues(path))
+
+		responseStatus.WithLabelValues(strconv.Itoa(http.StatusOK)).Inc()
+		totalRequests.WithLabelValues(path).Inc()
+
+		timer.ObserveDuration()
+		next.ServeHTTP(w, r)
+	})
+
+}

internal/proxy.go

@@ -29,7 +29,7 @@ import (
 // ProxyHandler proxies requests to the backend
 func (proxyRoute ProxyRoute) ProxyHandler() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		logger.Info("%s %s %s %s", r.Method, getRealIP(r), r.URL, r.UserAgent())
+		logger.Info("%s %s %s %s", r.Method, getRealIP(r), r.URL.Path, r.UserAgent())
 		// Check Method if is allowed
 		if len(proxyRoute.methods) > 0 {
 			if !slices.Contains(proxyRoute.methods, r.Method) {

internal/route.go

@@ -20,9 +20,17 @@ import (
 	"github.com/jkaninda/goma-gateway/internal/middleware"
 	"github.com/jkaninda/goma-gateway/pkg/logger"
 	"github.com/jkaninda/goma-gateway/util"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"time"
 )
 
+func init() {
+	_ = prometheus.Register(totalRequests)
+	_ = prometheus.Register(responseStatus)
+	_ = prometheus.Register(httpDuration)
+}
+
 // Initialize the routes
 func (gatewayServer GatewayServer) Initialize() *mux.Router {
 	gateway := gatewayServer.gateway
@@ -32,11 +40,18 @@ func (gatewayServer GatewayServer) Initialize() *mux.Router {
 		DisableRouteHealthCheckError: gateway.DisableRouteHealthCheckError,
 		Routes:                       gateway.Routes,
 	}
+	if gateway.EnableMetrics {
+		// Prometheus endpoint
+		r.Path("/metrics").Handler(promhttp.Handler())
+		r.Use(prometheusMiddleware)
+	}
+
 	// Routes health check
 	if !gateway.DisableHealthCheckStatus {
 		r.HandleFunc("/healthz", heath.HealthCheckHandler).Methods("GET")
 		r.HandleFunc("/health/routes", heath.HealthCheckHandler).Methods("GET")
 	}
+
 	// Health check
 	r.HandleFunc("/health/live", heath.HealthReadyHandler).Methods("GET")
 	r.HandleFunc("/readyz", heath.HealthReadyHandler).Methods("GET")
@@ -223,6 +238,7 @@ func (gatewayServer GatewayServer) Initialize() *mux.Router {
 			} else {
 				router.PathPrefix("").Handler(proxyRoute.ProxyHandler())
 			}
+
 		} else {
 			logger.Error("Error, path is empty in route %s", route.Name)
 			logger.Error("Route path ignored: %s", route.Path)

internal/types.go

@@ -196,6 +196,7 @@ type Gateway struct {
 	DisableDisplayRouteOnStart bool `yaml:"disableDisplayRouteOnStart"`
 	// DisableKeepAlive allows enabling and disabling KeepALive server
 	DisableKeepAlive bool `yaml:"disableKeepAlive"`
+	EnableMetrics    bool `yaml:"enableMetrics"`
 	// InterceptErrors holds the status codes to intercept the error from backend
 	InterceptErrors []int `yaml:"interceptErrors"`
 	// Cors holds proxy global cors