[New feature] Added metrics

cmd/kube-nftlb-client/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"github.com/zevenet/kube-nftlb/pkg/auth"
 	"github.com/zevenet/kube-nftlb/pkg/controller"
+	"github.com/zevenet/kube-nftlb/pkg/metrics"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/tools/cache"
 )
@@ -19,6 +20,9 @@ func main() {
 		// TODO Enable NetworkPolicyController after nftlb fully supports policies
 	}
 
+	// Start metrics server
+	go metrics.StartServer()
+
 	// Run controllers as background processes
 	for _, controller := range controllers {
 		go controller.Run(wait.NeverStop)

pkg/controller/endpoints.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/zevenet/kube-nftlb/pkg/http"
 	"github.com/zevenet/kube-nftlb/pkg/log"
+	"github.com/zevenet/kube-nftlb/pkg/metrics"
 	"github.com/zevenet/kube-nftlb/pkg/parser"
 	"github.com/zevenet/kube-nftlb/pkg/types"
 	"github.com/zevenet/kube-nftlb/pkg/watcher"
@@ -60,12 +61,16 @@ func AddNftlbBackends(obj interface{}) {
 	}
 	log.WriteLog(types.StandardLog, fmt.Sprintf("AddNftlbBackends: Endpoints name: %s\n%s", ep.Name, nftlbJSON))
 
+	metrics.EndpointsChangesPending.Inc()
+	metrics.EndpointsChangesTotal.Inc()
 	// Get the response from that request
 	response, err := http.Send(&types.RequestData{
 		Method: "POST",
 		Path:   "farms",
 		Body:   strings.NewReader(nftlbJSON),
 	})
+	metrics.EndpointsChangesPending.Dec()
+
 	if err != nil {
 		log.WriteLog(types.ErrorLog, fmt.Sprintf("AddNftlbBackends: Endpoints name: %s\n%s", ep.Name, err.Error()))
 		return
@@ -76,6 +81,7 @@ func AddNftlbBackends(obj interface{}) {
 
 // DeleteNftlbBackends
 func DeleteNftlbBackends(obj interface{}) {
+	metrics.EndpointsChangesTotal.Inc()
 	ep := obj.(*corev1.Endpoints)
 	pathsChan := make(chan string)
 

pkg/controller/service.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/zevenet/kube-nftlb/pkg/http"
 	"github.com/zevenet/kube-nftlb/pkg/log"
+	"github.com/zevenet/kube-nftlb/pkg/metrics"
 	"github.com/zevenet/kube-nftlb/pkg/parser"
 	"github.com/zevenet/kube-nftlb/pkg/types"
 	"github.com/zevenet/kube-nftlb/pkg/watcher"
@@ -56,12 +57,16 @@ func AddNftlbFarm(obj interface{}) {
 		return
 	}
 
+	metrics.ServicesChangesPending.Inc()
+	metrics.ServicesChangesTotal.Inc()
 	// Send that JSON data to nftlb
 	response, err := http.Send(&types.RequestData{
 		Method: "POST",
 		Path:   "farms",
 		Body:   strings.NewReader(nftlbJSON),
 	})
+	metrics.ServicesChangesPending.Dec()
+
 	if err != nil {
 		log.WriteLog(types.ErrorLog, fmt.Sprintf("AddNftlbFarms: Service name: %s\n%s", svc.Name, err.Error()))
 		return
@@ -73,6 +78,7 @@ func AddNftlbFarm(obj interface{}) {
 
 // DeleteNftlbFarm takes in a Service object (k8s) and deletes the farm related to the service and its addresses (nftlb).
 func DeleteNftlbFarm(obj interface{}) {
+	metrics.ServicesChangesTotal.Inc()
 	svc := obj.(*corev1.Service)
 
 	// Make channel where paths will come through

pkg/metrics/endpoints.go

@@ -0,0 +1,19 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	EndpointsChangesPending = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "kube_nftlb",
+		Name:      "rules_endpoints_changes_pending",
+		Help:      "How many Endpoints are pending to apply",
+	})
+
+	EndpointsChangesTotal = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "kube_nftlb",
+		Name:      "rules_endpoints_changes_total",
+		Help:      "How many Endpoints changes have happened",
+	})
+)

pkg/metrics/server.go

@@ -0,0 +1,45 @@
+package metrics
+
+import (
+	"flag"
+	"log"
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var (
+	defaultAddress = ":9195"
+	address        = flag.String("listen-address", defaultAddress, "The address to listen on for HTTP requests.")
+	collectors     = []prometheus.Collector{
+		EndpointsChangesPending,
+		EndpointsChangesTotal,
+		ServicesChangesPending,
+		ServicesChangesTotal,
+	}
+)
+
+func StartServer() {
+	flag.Parse()
+
+	if *address == "" {
+		*address = defaultAddress
+	}
+
+	for _, collector := range collectors {
+		prometheus.MustRegister(collector)
+	}
+
+	http.Handle("/metrics", promhttp.Handler())
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(`<html>
+             <head><title>kube-nftlb Exporter</title></head>
+             <body>
+             <h1>kube-nftlb Exporter</h1>
+             <p><a href='/metrics'>Metrics</a></p>
+             </body>
+             </html>`))
+	})
+	log.Fatal(http.ListenAndServe(*address, nil))
+}

pkg/metrics/services.go

@@ -0,0 +1,19 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	ServicesChangesPending = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "kube_nftlb",
+		Name:      "rules_services_changes_pending",
+		Help:      "How many Services are pending to apply",
+	})
+
+	ServicesChangesTotal = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "kube_nftlb",
+		Name:      "rules_services_changes_total",
+		Help:      "How many Services changes have happened",
+	})
+)

yaml/kube-nftlb-ds.yaml

@@ -25,6 +25,8 @@ spec:
         - name: kube-nftlb
           image: zevenet/kube-nftlb
           imagePullPolicy: IfNotPresent
+          ports:
+          - containerPort: 9195
           resources:
             limits:
               memory: 200Mi