First commit

.gitignore

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+.idea/
+host-rewriter

go.mod

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+module github.com/MrMelon54/host-rewriter
+
+go 1.21.3

host-rewriter.go

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+package main
+
+import (
+	"flag"
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"time"
+)
+
+var listenFlag, targetFlag, hostFlag string
+
+func main() {
+	flag.StringVar(&listenFlag, "listen", ":8080", "Listen address")
+	flag.StringVar(&targetFlag, "target", "", "Set target URL to forward to")
+	flag.StringVar(&hostFlag, "host", "", "Set the host value")
+	flag.Parse()
+
+	target, err := url.Parse(targetFlag)
+	if err != nil {
+		log.Fatal("Failed to parse target URL:", err)
+	}
+
+	proxy := &httputil.ReverseProxy{
+		Rewrite: func(r *httputil.ProxyRequest) {
+			r.SetURL(target)
+			r.Out.Host = hostFlag
+		},
+	}
+	s := http.Server{
+		Addr:              listenFlag,
+		Handler:           proxy,
+		ReadTimeout:       150 * time.Second,
+		ReadHeaderTimeout: 150 * time.Second,
+		WriteTimeout:      150 * time.Second,
+		IdleTimeout:       150 * time.Second,
+		MaxHeaderBytes:    4096000,
+	}
+
+	log.Printf("Host Rewriter listening on %s\n", listenFlag)
+	log.Printf("Rewriting host to '%s' and forwarding to '%s'\n", hostFlag, targetFlag)
+	if err := s.ListenAndServe(); err != nil {
+		log.Fatal(err)
+	}
+}