Merge pull request #29 from jelmersnoeck/add-metrics-server

Add Prometheus Metrics server.

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Log when something goes wrong with GarbageCollection.
 - Use a queue based system to sync items.
+- Added `/_healthz` endpoint and set up probes.
+- Added `/metrics` endpoint for Prometheus.
 
 ### Fixed
 
@@ -20,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Set up lower resource requests/limits for the Deployment.
 - MonitorTemplate is now namespace scoped instead of cluster scoped.
+- The operator now uses cache informers to reconcile state.
 
 ## v0.1.1 - 2018-09-02
 

Gopkg.toml

@@ -36,3 +36,7 @@ required = [
 [[constraint]]
   branch = "master"
   name = "github.com/DreamItGetIT/statuscake"
+
+[[constraint]]
+  name = "github.com/prometheus/client_golang"
+  version = "0.8.0"

internal/httpsvc/metrics.go

@@ -0,0 +1,35 @@
+package httpsvc
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+// Metrics represents a Metrics server which can be used to expose a prometheus
+// metrics.
+type Metrics struct {
+	Server
+	*prometheus.Registry
+}
+
+// Start starts the Health Server.
+func (s *Metrics) Start(stopCh <-chan struct{}) error {
+	registerMetrics(&s.ServeMux, s.Registry)
+	registerHealthCheck(&s.ServeMux)
+
+	return s.Server.Start(stopCh)
+}
+
+func registerMetrics(mux *http.ServeMux, reg *prometheus.Registry) {
+	mux.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{}))
+}
+
+func registerHealthCheck(mux *http.ServeMux) {
+	mux.HandleFunc("/_healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprintln(w, "OK")
+	})
+}

internal/ingressmonitor/cmd/operator.go

@@ -2,16 +2,20 @@ package cmd
 
 import (
 	"log"
+	"os"
 	"time"
 
 	"github.com/jelmersnoeck/ingress-monitor/internal/httpsvc"
 	"github.com/jelmersnoeck/ingress-monitor/internal/ingressmonitor"
+	"github.com/jelmersnoeck/ingress-monitor/internal/metrics"
 	"github.com/jelmersnoeck/ingress-monitor/internal/provider"
 	"github.com/jelmersnoeck/ingress-monitor/internal/provider/logger"
 	"github.com/jelmersnoeck/ingress-monitor/internal/provider/statuscake"
 	"github.com/jelmersnoeck/ingress-monitor/internal/signals"
 	"github.com/jelmersnoeck/ingress-monitor/pkg/client/generated/clientset/versioned"
 
+	"github.com/prometheus/client_golang/prometheus"
+
 	"github.com/spf13/cobra"
 	"k8s.io/api/core/v1"
 	"k8s.io/client-go/kubernetes"
@@ -24,8 +28,8 @@ var operatorFlags struct {
 	KubeConfig   string
 	ResyncPeriod string
 
-	HTTPAddr string
-	HTTPPort int
+	MetricsAddr string
+	MetricsPort int
 }
 
 // operatorCmd represents the operator command
@@ -63,18 +67,25 @@ func runOperator(cmd *cobra.Command, args []string) {
 	statuscake.Register(fact)
 	logger.Register(fact)
 
-	// register the health server
-	healthSrv := &httpsvc.Health{
+	// create new prometheus registry
+	registry := prometheus.NewRegistry()
+	registry.MustRegister(prometheus.NewProcessCollector(os.Getpid(), ""))
+	registry.MustRegister(prometheus.NewGoCollector())
+
+	// new metrics collector
+	mtrc := metrics.New(registry)
+	metricssvc := httpsvc.Metrics{
 		Server: httpsvc.Server{
-			Addr: operatorFlags.HTTPAddr,
-			Port: operatorFlags.HTTPPort,
+			Addr: operatorFlags.MetricsAddr,
+			Port: operatorFlags.MetricsPort,
 		},
+		Registry: registry,
 	}
-	go healthSrv.Start(stopCh)
+	go metricssvc.Start(stopCh)
 
 	op, err := ingressmonitor.NewOperator(
 		kubeClient, imClient, operatorFlags.Namespace,
-		resync, fact,
+		resync, fact, mtrc,
 	)
 	if err != nil {
 		log.Fatalf("Error building IngressMonitor Operator: %s", err)
@@ -93,6 +104,6 @@ func init() {
 	operatorCmd.PersistentFlags().StringVar(&operatorFlags.KubeConfig, "kubeconfig", "", "Kubeconfig which should be used to talk to the API.")
 	operatorCmd.PersistentFlags().StringVar(&operatorFlags.ResyncPeriod, "resync-period", "30s", "Resyncing period to ensure all monitors are up to date.")
 
-	operatorCmd.PersistentFlags().StringVar(&operatorFlags.HTTPAddr, "http-addr", "0.0.0.0", "address the health server will bind to")
-	operatorCmd.PersistentFlags().IntVar(&operatorFlags.HTTPPort, "http-port", 9090, "port on which the health server is available")
+	operatorCmd.PersistentFlags().StringVar(&operatorFlags.MetricsAddr, "metrics-addr", "0.0.0.0", "address the metrics server will bind to")
+	operatorCmd.PersistentFlags().IntVar(&operatorFlags.MetricsPort, "metrics-port", 9090, "port on which the metrics server is available")
 }