Create CLI option to bind to UNIX socket (#265)

cmd/tusd/cli/flags.go

@@ -8,6 +8,7 @@ import (
 var Flags struct {
 	HttpHost          string
 	HttpPort          string
+	HttpSock          string
 	MaxSize           int64
 	UploadDir         string
 	StoreSize         int64
@@ -16,7 +17,7 @@ var Flags struct {
 	S3Bucket          string
 	S3ObjectPrefix    string
 	S3Endpoint        string
-	GCSBucket     	  string
+	GCSBucket         string
 	FileHooksDir      string
 	HttpHooksEndpoint string
 	HttpHooksRetry    int
@@ -33,6 +34,7 @@ var Flags struct {
 func ParseFlags() {
 	flag.StringVar(&Flags.HttpHost, "host", "0.0.0.0", "Host to bind HTTP server to")
 	flag.StringVar(&Flags.HttpPort, "port", "1080", "Port to bind HTTP server to")
+	flag.StringVar(&Flags.HttpSock, "unix-sock", "", "If set, will listen to a UNIX socket at this location instead of a TCP socket")
 	flag.Int64Var(&Flags.MaxSize, "max-size", 0, "Maximum size of a single upload in bytes")
 	flag.StringVar(&Flags.UploadDir, "dir", "./data", "Directory to store uploads in")
 	flag.Int64Var(&Flags.StoreSize, "store-size", 0, "Size of space allowed for storage")

cmd/tusd/cli/listener.go

@@ -1,7 +1,9 @@
 package cli
 
 import (
+	"errors"
 	"net"
+	"os"
 	"time"
 )
 
@@ -98,3 +100,40 @@ func NewListener(addr string, readTimeout, writeTimeout time.Duration) (net.List
 	}
 	return tl, nil
 }
+
+// Binds to a UNIX socket. If the file already exists, try to remove it before
+// binding again. This logic is borrowed from Gunicorn
+// (see https://github.com/benoitc/gunicorn/blob/a8963ef1a5a76f3df75ce477b55fe0297e3b617d/gunicorn/sock.py#L106)
+func NewUnixListener(path string, readTimeout, writeTimeout time.Duration) (net.Listener, error) {
+	stat, err := os.Stat(path)
+
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return nil, err
+		}
+	} else {
+		if stat.Mode()&os.ModeSocket != 0 {
+			err = os.Remove(path)
+
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			return nil, errors.New("specified path is not a socket")
+		}
+	}
+
+	l, err := net.Listen("unix", path)
+
+	if err != nil {
+		return nil, err
+	}
+
+	tl := &Listener{
+		Listener:     l,
+		ReadTimeout:  readTimeout,
+		WriteTimeout: writeTimeout,
+	}
+
+	return tl, nil
+}

cmd/tusd/cli/serve.go

@@ -1,12 +1,19 @@
 package cli
 
 import (
+	"net"
 	"net/http"
 	"time"
 
 	"github.com/tus/tusd"
 )
 
+// Setups the different components, starts a Listener and give it to
+// http.Serve().
+//
+// By default it will bind to the specified host/port, unless a UNIX socket is
+// specified, in which case a different socket creation and binding mechanism
+// is put in place.
 func Serve() {
 	SetupPreHooks(Composer)
 
@@ -24,10 +31,17 @@ func Serve() {
 		stderr.Fatalf("Unable to create handler: %s", err)
 	}
 
-	address := Flags.HttpHost + ":" + Flags.HttpPort
 	basepath := Flags.Basepath
+	address := ""
+
+	if Flags.HttpSock != "" {
+		address = Flags.HttpSock
+		stdout.Printf("Using %s as socket to listen.\n", address)
+	} else {
+		address = Flags.HttpHost + ":" + Flags.HttpPort
+		stdout.Printf("Using %s as address to listen.\n", address)
+	}
 
-	stdout.Printf("Using %s as address to listen.\n", address)
 	stdout.Printf("Using %s as the base path.\n", basepath)
 
 	SetupPostHooks(handler)
@@ -47,8 +61,15 @@ func Serve() {
 
 	http.Handle(basepath, http.StripPrefix(basepath, handler))
 
+	var listener net.Listener
 	timeoutDuration := time.Duration(Flags.Timeout) * time.Millisecond
-	listener, err := NewListener(address, timeoutDuration, timeoutDuration)
+
+	if Flags.HttpSock != "" {
+		listener, err = NewUnixListener(address, timeoutDuration, timeoutDuration)
+	} else {
+		listener, err = NewListener(address, timeoutDuration, timeoutDuration)
+	}
+
 	if err != nil {
 		stderr.Fatalf("Unable to create listener: %s", err)
 	}