master-slave-mode

go.mod

@@ -0,0 +1,10 @@
+module git.send.nrw/sendnrw/flod-pod
+
+go 1.24.3
+
+require github.com/redis/go-redis/v9 v9.10.0
+
+require (
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+)

go.sum

@@ -0,0 +1,6 @@
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
+github.com/redis/go-redis/v9 v9.10.0 h1:FxwK3eV8p/CQa0Ch276C7u2d0eNC9kCmAYQ7mCXCzVs=
+github.com/redis/go-redis/v9 v9.10.0/go.mod h1:huWgSWd8mW6+m0VPhJjSSQ+d6Nh1VICQ6Q5lHuCH/Iw=

main.go

@@ -0,0 +1,144 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/redis/go-redis/v9"
+)
+
+var (
+	ctx           = context.Background()
+	redisClient   *redis.Client
+	hashName      = "bl:cat"
+	blocklistMode string
+	masterURL     string
+)
+
+func main() {
+	// Modus und Master-URL aus ENV
+	blocklistMode = os.Getenv("BLOCKLIST_MODE")
+	if blocklistMode != "master" && blocklistMode != "slave" {
+		log.Fatal("BLOCKLIST_MODE muss 'master' oder 'slave' sein")
+	}
+
+	if blocklistMode == "slave" {
+		masterURL = os.Getenv("MASTER_URL")
+		if masterURL == "" {
+			log.Fatal("MASTER_URL muss gesetzt sein im slave Modus")
+		}
+	}
+
+	if blocklistMode == "master" {
+		// Redis initialisieren
+		redisAddr := os.Getenv("REDIS_ADDR")
+		if redisAddr == "" {
+			redisAddr = "localhost:6379"
+		}
+		redisClient = redis.NewClient(&redis.Options{
+			Addr:     redisAddr,
+			Password: "",
+			DB:       0,
+		})
+		if err := redisClient.Ping(ctx).Err(); err != nil {
+			log.Fatalf("Keine Verbindung zu Redis: %v", err)
+		}
+	}
+
+	// Endpunkte registrieren
+	http.HandleFunc("/", handleRoot)
+	http.HandleFunc("/add", handleAdd)
+
+	log.Println("Server läuft im Modus:", blocklistMode)
+	log.Println("Server startet auf :8080")
+	if err := http.ListenAndServe(":8080", nil); err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}
+
+func handleRoot(w http.ResponseWriter, r *http.Request) {
+	ip := getClientIP(r)
+	if ip == "" {
+		http.Error(w, "Ungültige IP", http.StatusBadRequest)
+		return
+	}
+
+	processIP(ip, w)
+}
+
+func handleAdd(w http.ResponseWriter, r *http.Request) {
+	body, err := io.ReadAll(r.Body)
+	if err != nil || len(body) == 0 {
+		http.Error(w, "Ungültiger Body", http.StatusBadRequest)
+		return
+	}
+	ip := strings.TrimSpace(string(body))
+	if !isValidIP(ip) {
+		http.Error(w, "Ungültige IP", http.StatusBadRequest)
+		return
+	}
+
+	processIP(ip, w)
+}
+
+func processIP(ip string, w http.ResponseWriter) {
+	ipKey := ip + "/32"
+
+	if blocklistMode == "master" {
+		err := redisClient.HSet(ctx, hashName, ipKey, 1).Err()
+		if err != nil {
+			log.Printf("Fehler beim Schreiben in Redis: %v", err)
+			http.Error(w, "Interner Fehler", http.StatusInternalServerError)
+			return
+		}
+		log.Printf("IP %s in Redis gespeichert", ipKey)
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("IP gespeichert: " + ipKey + "\n"))
+	} else {
+		// Slave: an Master weiterleiten
+		resp, err := http.Post(masterURL+"/add", "text/plain", bytes.NewBuffer([]byte(ip)))
+		if err != nil {
+			log.Printf("Fehler beim Weiterleiten an Master: %v", err)
+			http.Error(w, "Fehler beim Weiterleiten", http.StatusBadGateway)
+			return
+		}
+		defer resp.Body.Close()
+		w.WriteHeader(resp.StatusCode)
+		io.Copy(w, resp.Body)
+	}
+}
+
+func getClientIP(r *http.Request) string {
+	xff := r.Header.Get("X-Forwarded-For")
+	if xff != "" {
+		parts := strings.Split(xff, ",")
+		ip := strings.TrimSpace(parts[0])
+		if isValidIP(ip) {
+			return ip
+		}
+	}
+
+	xrip := r.Header.Get("X-Real-Ip")
+	if xrip != "" && isValidIP(xrip) {
+		return xrip
+	}
+
+	host, _, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		return ""
+	}
+	if isValidIP(host) {
+		return host
+	}
+	return ""
+}
+
+func isValidIP(ip string) bool {
+	return net.ParseIP(ip) != nil
+}