add code to load country code by user IP address

src/bunker.go

@@ -299,6 +299,14 @@ func (e mainEnv) setupRouter() *httprouter.Router {
 			// next step: https://www.sanarias.com/blog/115LearningHTTPcachinginGo
 			w.Header().Set("Cache-Control", "public, max-age=7776000")
 			w.WriteHeader(200)
+			if strings.HasSuffix(r.URL.Path, ".js") || strings.HasSuffix(r.URL.Path, ".html") {
+				if bytes.Contains(data, []byte("%IPCOUNTRY%")) {
+					ipCountry := getCountry(r)
+					data2 := bytes.ReplaceAll(data, []byte("%IPCOUNTRY%"), []byte(ipCountry))
+					w.Write([]byte(data2))
+					return
+				}
+			}
 			w.Write([]byte(data))
 		}
 	})
@@ -624,6 +632,7 @@ func main() {
 	db := &dbcon{store, masterKey, hash[:]}
 	e := mainEnv{db, cfg, make(chan struct{})}
 	e.dbCleanup()
+	initGeoIP()
 	initCaptcha(hash)
 	router := e.setupRouter()
 	router = e.setupConfRouter(router)

src/geoip.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"log"
+	"net"
+	"net/http"
+	"strings"
+	"github.com/gobuffalo/packr"
+	"github.com/oschwald/geoip2-golang"
+)
+
+var (
+	geoipBytes []byte
+	geoip * geoip2.Reader
+)
+
+
+func initGeoIP() {
+	var err error
+	box := packr.NewBox("../ui")
+	geoipBytes, err = box.Find("site/GeoLite2-Country.mmdb")
+	if err != nil {
+		log.Fatalf("Failed to load geoip database file")
+		return
+	}
+	geoip, err = geoip2.FromBytes(geoipBytes)
+	if err != nil {
+		log.Fatalf("Failed to load geoip database")
+		return
+	}
+	//captchaKey = h
+}
+
+func getCountry(r *http.Request) string {
+	userIP := ""
+	//log.Printf("Headers %v", r.Header)
+	if len(r.Header.Get("CF-Connecting-IP")) > 1 {
+		userIP = strings.TrimSpace(r.Header.Get("CF-Connecting-IP"))
+	}
+	if len(r.Header.Get("X-Forwarded-For")) > 1 && len(userIP) == 0 {
+		userIP = strings.TrimSpace(r.Header.Get("X-Forwarded-For"))
+	}
+	if len(r.Header.Get("X-Real-IP")) > 1 && len(userIP) == 0 {
+		userIP = strings.TrimSpace(r.Header.Get("X-Real-IP"))
+	}
+	if len(userIP) == 0 {
+		userIP = r.RemoteAddr
+	}
+	if strings.Contains(userIP, ",") {
+		userIP = strings.Split(userIP, ",")[0]
+	}
+	if strings.Contains(userIP, " ") {
+		userIP = strings.Split(userIP, " ")[0]
+	}
+	if len(userIP) == 0 {
+		return ""
+	}
+	ip := net.ParseIP(userIP)
+	if ip == nil {
+		if strings.Count(userIP, ":") == 1 {
+			userIP = strings.Split(userIP, ":")[0]
+			ip = net.ParseIP(userIP)
+		}
+		if ip == nil {
+			log.Printf("Failed to parse userIP: %s", userIP)
+			return ""
+		}
+	}
+	record, err := geoip.Country(ip)
+	if err != nil {
+		log.Printf("Failed to detect country using IP address: %s", userIP)
+		return ""
+	}
+	return record.Country.IsoCode
+}