1 files changed, 85 insertions, 0 deletions
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..c2b331e
--- /dev/null
+++ b/main.go
@@ -0,0 +1,85 @@
+// Copyright (c) 2019, Grégoire Duchêne <gduchene@awhk.org>
+//
+// Use of this source code is governed by the ISC license that can be
+// found in the LICENSE file.
+
+// +build !aws
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"path"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+func redirect(resp http.ResponseWriter, req *http.Request) {
+	if req.Method != http.MethodGet {
+		resp.Header().Set("Allow", http.MethodGet)
+		resp.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+
+	pkg := path.Join(req.Host, req.URL.Path)
+	resp.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if req.URL.Query().Get("go-get") == "1" {
+		resp.WriteHeader(http.StatusOK)
+	} else {
+		resp.Header().Set("Location", "https://pkg.go.dev/"+pkg)
+		resp.WriteHeader(http.StatusFound)
+	}
+	if _, err := fmt.Fprint(resp, GetBody(pkg)); err != nil {
+		log.Println("fmt.Fprint:", err)
+	}
+}
+
+func main() {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", redirect)
+	srv := http.Server{Handler: mux}
+
+	done := make(chan os.Signal, 1)
+	signal.Notify(done, os.Interrupt, unix.SIGTERM)
+
+	go func() {
+		var (
+			addr = os.Getenv("ADDR")
+			l    net.Listener
+			err  error
+		)
+		if addr != "" && addr[0] == '/' {
+			if l, err = net.Listen("unix", addr); err != nil {
+				log.Fatalln("net.Listen:", err)
+			}
+			// We do not do any authorization anyway, so 0666 makes sense here.
+			if err = os.Chmod(addr, 0666); err != nil {
+				log.Fatalln("os.Chmod:", err)
+			}
+		} else {
+			if addr == "" {
+				addr = ":8080"
+			}
+			if l, err = net.Listen("tcp", addr); err != nil {
+				log.Fatalln("net.Listen:", err)
+			}
+		}
+		if err = srv.Serve(l); err != nil && err != http.ErrServerClosed {
+			log.Fatalln("server.ListenAndServe:", err)
+		}
+	}()
+
+	<-done
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	if err := srv.Shutdown(ctx); err != nil && err != http.ErrServerClosed {
+		log.Fatalln("server.Shutdown:", err)
+	}
+}