starting webserver

cmd/go-temper/config.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"os"
+	"time"
+
+	"github.com/hashicorp/logutils"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type configStructure struct {
+	// time configuration
+	TimeFormat  string `json:"time_format"`
+	TimeZone    *time.Location
+	TimeZoneUTC *time.Location
+
+	// logging
+	Log *logutils.LevelFilter
+
+	// webserver
+	WebSrvPort         int    `json:"webserver_port"`
+	WebSrvIP           string `json:"webserver_ip"`
+	WebSrvReadTimeout  int    `json:"webserver_read_timeout"`
+	WebSrvWriteTimeout int    `json:"webserver_write_timeout"`
+	WebSrvIdleTimeout  int    `json:"webserver_idle_timeout"`
+
+	// prometheus
+	Prometheus configPrometheus
+}
+
+type configPrometheus struct {
+	Temperature prometheus.Gauge
+}
+
+var config = configStructure{
+	TimeFormat: "2006-01-02 15:04:05",
+	Log: &logutils.LevelFilter{
+		Levels: []logutils.LogLevel{"TRACE", "DEBUG", "INFO", "WARNING", "ERROR"},
+		Writer: os.Stderr,
+	},
+	WebSrvReadTimeout:  5,
+	WebSrvWriteTimeout: 2,
+	WebSrvIdleTimeout:  2,
+}

cmd/go-temper/httpServer.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+func httpAccessLog(req *http.Request) {
+	log.Printf("[TRACE] %s - %s - %s\n", req.Method, req.RemoteAddr, req.RequestURI)
+}
+
+func crossSiteOrigin(w http.ResponseWriter) {
+	w.Header().Add("Access-Control-Allow-Origin", "*")
+	w.Header().Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
+	w.Header().Add("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, Authorization, X-API-Token")
+}
+
+func httpServer(host string, port int) {
+	path := http.NewServeMux()
+
+	connection := &http.Server{
+		Addr:         host + ":" + strconv.FormatInt(int64(port), 10),
+		Handler:      path,
+		ReadTimeout:  time.Duration(config.WebSrvReadTimeout) * time.Second,
+		WriteTimeout: time.Duration(config.WebSrvWriteTimeout) * time.Second,
+		IdleTimeout:  time.Duration(config.WebSrvIdleTimeout) * time.Second,
+	}
+
+	path.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		httpAccessLog(r)
+		w.Write([]byte("web-root"))
+	})
+	path.HandleFunc("/metrics", func(w http.ResponseWriter, r *http.Request) {
+		httpAccessLog(r)
+		crossSiteOrigin(w)
+		promhttp.Handler().ServeHTTP(w, r)
+	})
+
+	if err := connection.ListenAndServe(); err != nil {
+		log.Fatalf("[ERROR] %s\n", err)
+	}
+}

cmd/go-temper/main.go

@@ -8,6 +8,8 @@ import (
 )
 
 func main() {
+	go httpServer("0.0.0.0", 8080)
+
 	for {
 		temp, err := temper.GetTemperature()
 		if err != nil {