Adds readiness and liveness endpoints.

go.mod

@@ -3,7 +3,9 @@ module github.com/sberk42/fritzbox_exporter
 go 1.15
 
 require (
+	github.com/heptiolabs/healthcheck v0.0.0-20180807145615-6ff867650f40
 	github.com/namsral/flag v1.7.4-pre
 	github.com/prometheus/client_golang v1.10.0
 	golang.org/x/text v0.3.6
+	gopkg.in/DATA-DOG/go-sqlmock.v1 v1.3.0 // indirect
 )

health.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"github.com/heptiolabs/healthcheck"
+	"time"
+)
+
+// createHealthChecks will create the readiness and liveness endpoints and add the check functions.
+func createHealthChecks(gatewayUrl string) healthcheck.Handler {
+	health := healthcheck.NewHandler()
+
+	health.AddReadinessCheck("FRITZ!Box connection",
+		healthcheck.HTTPGetCheck(gatewayUrl+"/any.xml", time.Duration(3)*time.Second))
+
+	health.AddLivenessCheck("go-routines", healthcheck.GoroutineCountCheck(100))
+	return health
+}

main.go

@@ -847,8 +847,14 @@ func main() {
 		prometheus.MustRegister(collectLuaResultsLoaded)
 	}
 
+	healthChecks := createHealthChecks(*flagGatewayURL)
+
 	http.Handle("/metrics", promhttp.Handler())
 	fmt.Printf("metrics available at http://%s/metrics\n", *flagAddr)
+	http.HandleFunc("/ready", healthChecks.ReadyEndpoint)
+	fmt.Printf("readyness check available at http://%s/ready\n", *flagAddr)
+	http.HandleFunc("/live", healthChecks.LiveEndpoint)
+	fmt.Printf("liveness check available at http://%s/live\n", *flagAddr)
 
 	log.Fatal(http.ListenAndServe(*flagAddr, nil))
 }