Introduce /httpStatus endpoint

which will respond with HTTP200 if everything is fine or HTTP500 if one
or more certificates are broken

Signed-off-by: Knut Ahlers <knut@ahlers.me>

http.go

@@ -26,6 +26,17 @@ func htmlHandler(res http.ResponseWriter, r *http.Request) {
 	}, res)
 }
 
+func httpStatusHandler(res http.ResponseWriter, r *http.Request) {
+	httpStatus := http.StatusOK
+	for _, mon := range probeMonitors {
+		if mon.Status != certificateOK {
+			httpStatus = http.StatusInternalServerError
+		}
+	}
+
+	res.WriteHeader(httpStatus)
+}
+
 func jsonHandler(res http.ResponseWriter, r *http.Request) {
 	res.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(res).Encode(probeMonitors)

main.go

@@ -61,6 +61,7 @@ func main() {
 	r := mux.NewRouter()
 	r.Handle("/metrics", prometheus.Handler())
 	r.HandleFunc("/", htmlHandler)
+	r.HandleFunc("/httpStatus", httpStatusHandler)
 	r.HandleFunc("/results.json", jsonHandler)
 	http.ListenAndServe(":3000", r)
 }