Moving to kube, refactoring code, using env variables only, adding metrics exporter

app/Http/utils.go

@@ -2,31 +2,104 @@
 package http
 
 import (
+	prometheus "http-broadcaster/Prometheus"
+	tools "http-broadcaster/Tools"
 	varnish "http-broadcaster/Varnish"
 	"io"
 	"log"
 	"net/http"
+	"net/netip"
+	"strconv"
+	"time"
 )
 
+// logRequest print the requests and wanted informations in log file
+func logRequest(t time.Time, r *http.Request, s int, h map[string]string) {
+	// Test if X-Cache-Tags header is empty
+	if len(h) == 0 {
+		log.Printf("%s %s - - %s \"%s %s %s\" %d 0 \"-\" \"%s\" %d\n",
+			r.Host,
+			r.Header["X-Real-Ip"][0],
+			t.Format("[02/Jan/2006:15:04:05 -0700]"),
+			r.Method,
+			r.URL.Path,
+			r.Proto,
+			s,
+			r.UserAgent(),
+			time.Since(t).Milliseconds(),
+		)
+	} else {
+		var header string
+		if h["X-Cache-Tags"] != "" {
+			header = h["X-Cache-Tags"]
+		} else {
+			header = h["ApiPlatform-Ban-Regex"]
+		}
+		log.Printf("%s %s - - %s \"%s %s %s\" %d 0 \"-\" \"%s\" %d %s\n",
+			r.Host,
+			r.Header["X-Real-Ip"][0],
+			t.Format("[02/Jan/2006:15:04:05 -0700]"),
+			r.Method,
+			r.URL.Path,
+			r.Proto,
+			s,
+			r.UserAgent(),
+			time.Since(t).Milliseconds(),
+			header,
+		)
+	}
+}
+
+// checkAllowedIP verify if the IPs is authorized to do BAN/PURGE request.
+func checkAllowedIP(ip netip.Addr) bool {
+	return tools.IPAllowed(ip)
+}
+
 // RequestHandler handles requests to broadcast to all varnish instances.
 func RequestHandler(w http.ResponseWriter, r *http.Request) {
+	var tag = make(map[string]string)
+	// check x-real-ip instead of RemoteAddr header because kube
+	ip, err := netip.ParseAddr(r.Header["X-Real-Ip"][0])
+	if err != nil {
+		panic(err)
+	}
+	// If IP is not authorized to do purge/ban requests, respond with 401.
+	if !checkAllowedIP(ip) {
+		log.Printf("Client ip not authorized : %v", ip)
+		w.WriteHeader(401)
+		_, _ = io.WriteString(w, strconv.Itoa(401))
+		return
+	}
+	// If metrics are not enabled, return 404 on /metrics path.
+	if r.URL.Path == "/metrics" && !prometheus.MetricsEnabled {
+		w.WriteHeader(404)
+		_, _ = io.WriteString(w, strconv.Itoa(404))
+		return
+	}
+	t := time.Now()
 	url := r.URL.String()
 	method := r.Method
-	tag := r.Header.Get("X-Cache-Tags")
-	remoteAddr := r.RemoteAddr
+	h := r.Header.Get("X-Cache-Tags")
+	if h != "" {
+		tag["X-Cache-Tags"] = h
+	}
+	h = r.Header.Get("ApiPlatform-Ban-Regex")
+	if h != "" {
+		tag["ApiPlatform-Ban-Regex"] = h
+	}
 	status := varnish.SendToVarnish(method, url, tag)
-	if status != "200 Purged" {
+	if prometheus.MetricsEnabled {
+		prometheus.IncrementClientCounterVec(method)
+	}
+	// Return HTTP code 405 if not all varnish servers returned 200.
+	if status != 200 {
 		w.WriteHeader(405)
 	}
-	if tag != "" {
-		log.Println(remoteAddr + " Requested ban on X-Cache-Tags : " + tag + " , status: " + status)
-	} else {
-		log.Println(remoteAddr + " Requested purge on URI :" + url + " , status: " + status)
-	}
-	io.WriteString(w, status)
+	logRequest(t, r, status, tag)
+	_, _ = io.WriteString(w, strconv.Itoa(status))
 }
 
 // HealthHandler handles healthcheck requests and return 200.
 func HealthHandler(w http.ResponseWriter, _ *http.Request) {
-	io.WriteString(w, "OK")
+	_, _ = io.WriteString(w, "OK")
 }