Rename to http-dev

go.mod

@@ -1,3 +1,3 @@
-module github.com/MrMelon54/host-rewriter
+module github.com/1f349/http-dev
 
 go 1.21.3

host-rewriter.go

@@ -1,46 +0,0 @@
-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)
-	}
-}

http-dev.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"flag"
+	"io"
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"strings"
+	"time"
+)
+
+var listenFlag, targetFlag, hostFlag string
+var allowCors bool
+
+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.BoolVar(&allowCors, "cors", false, "Allow all cross origin requests")
+	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)
+			if hostFlag != "" {
+				r.Out.Host = hostFlag
+			}
+		},
+		ModifyResponse: func(response *http.Response) error {
+			if !allowCors {
+				return nil
+			}
+
+			response.Header.Add("Access-Control-Allow-Origin", "*")
+			response.Header.Add("Access-Control-Allow-Credentials", "true")
+			response.Header.Add("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
+			response.Header.Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
+
+			if response.Request.Method == "OPTIONS" {
+				_ = response.Body.Close()
+				response.Header.Set("Content-Type", "text/plain; charset=utf-8")
+				response.Header.Set("X-Content-Type-Options", "nosniff")
+				response.StatusCode = http.StatusNoContent
+				response.Status = http.StatusText(http.StatusNoContent)
+				response.Body = io.NopCloser(strings.NewReader("No Content\n"))
+			}
+			return nil
+		},
+	}
+	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("HTTP Dev listening on %s\n", listenFlag)
+	log.Printf("- Forwarding to '%s'\n", targetFlag)
+	if hostFlag != "" {
+		log.Printf("- Rewriting host to '%s'\n", hostFlag)
+	}
+	if allowCors {
+		log.Println("- Allowing all cross-origin requests")
+	}
+	if err := s.ListenAndServe(); err != nil {
+		log.Fatal(err)
+	}
+}