hostagent: split pkg/freeport

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

Author: AkihiroSuda

pkg/freeport/freeport.go

@@ -0,0 +1,51 @@
+// Package freeport provides functions to find free localhost ports.
+package freeport
+
+import (
+	"fmt"
+	"net"
+)
+
+func TCP() (int, error) {
+	lAddr0, err := net.ResolveTCPAddr("tcp4", "127.0.0.1:0")
+	if err != nil {
+		return 0, err
+	}
+	l, err := net.ListenTCP("tcp4", lAddr0)
+	if err != nil {
+		return 0, err
+	}
+	defer l.Close()
+	lAddr := l.Addr()
+	lTCPAddr, ok := lAddr.(*net.TCPAddr)
+	if !ok {
+		return 0, fmt.Errorf("expected *net.TCPAddr, got %v", lAddr)
+	}
+	port := lTCPAddr.Port
+	if port <= 0 {
+		return 0, fmt.Errorf("unexpected port %d", port)
+	}
+	return port, nil
+}
+
+func UDP() (int, error) {
+	lAddr0, err := net.ResolveUDPAddr("udp4", "127.0.0.1:0")
+	if err != nil {
+		return 0, err
+	}
+	l, err := net.ListenUDP("udp4", lAddr0)
+	if err != nil {
+		return 0, err
+	}
+	defer l.Close()
+	lAddr := l.LocalAddr()
+	lUDPAddr, ok := lAddr.(*net.UDPAddr)
+	if !ok {
+		return 0, fmt.Errorf("expected *net.UDPAddr, got %v", lAddr)
+	}
+	port := lUDPAddr.Port
+	if port <= 0 {
+		return 0, fmt.Errorf("unexpected port %d", port)
+	}
+	return port, nil
+}

pkg/freeport/freeport_unix.go

@@ -0,0 +1,9 @@
+//go:build !windows
+
+package freeport
+
+import "errors"
+
+func VSock() (int, error) {
+	return 0, errors.New("freeport.VSock is not implemented for non-Windows hosts")
+}

pkg/freeport/freeport_windows.go

@@ -0,0 +1,7 @@
+package freeport
+
+import "github.com/lima-vm/lima/pkg/windows"
+
+func VSock() (int, error) {
+	return windows.GetRandomFreeVSockPort(0, 2147483647)
+}

pkg/hostagent/hostagent.go

@@ -22,6 +22,7 @@ import (
 	"github.com/lima-vm/lima/pkg/cidata"
 	"github.com/lima-vm/lima/pkg/driver"
 	"github.com/lima-vm/lima/pkg/driverutil"
+	"github.com/lima-vm/lima/pkg/freeport"
 	guestagentapi "github.com/lima-vm/lima/pkg/guestagent/api"
 	guestagentclient "github.com/lima-vm/lima/pkg/guestagent/api/client"
 	hostagentapi "github.com/lima-vm/lima/pkg/hostagent/api"
@@ -108,11 +109,11 @@ func New(instName string, stdout io.Writer, signalCh chan os.Signal, opts ...Opt
 
 	var udpDNSLocalPort, tcpDNSLocalPort int
 	if *inst.Config.HostResolver.Enabled {
-		udpDNSLocalPort, err = findFreeUDPLocalPort()
+		udpDNSLocalPort, err = freeport.UDP()
 		if err != nil {
 			return nil, err
 		}
-		tcpDNSLocalPort, err = findFreeTCPLocalPort()
+		tcpDNSLocalPort, err = freeport.TCP()
 		if err != nil {
 			return nil, err
 		}
@@ -123,7 +124,7 @@ func New(instName string, stdout io.Writer, signalCh chan os.Signal, opts ...Opt
 	if *inst.Config.VMType == limayaml.VZ {
 		vSockPort = 2222
 	} else if *inst.Config.VMType == limayaml.WSL2 {
-		port, err := getFreeVSockPort()
+		port, err := freeport.VSock()
 		if err != nil {
 			logrus.WithError(err).Error("failed to get free VSock port")
 		}
@@ -250,57 +251,13 @@ func determineSSHLocalPort(confLocalPort int, instName string) (int, error) {
 		// use hard-coded value for "default" instance, for backward compatibility
 		return 60022, nil
 	}
-	sshLocalPort, err := findFreeTCPLocalPort()
+	sshLocalPort, err := freeport.TCP()
 	if err != nil {
 		return 0, fmt.Errorf("failed to find a free port, try setting `ssh.localPort` manually: %w", err)
 	}
 	return sshLocalPort, nil
 }
 
-func findFreeTCPLocalPort() (int, error) {
-	lAddr0, err := net.ResolveTCPAddr("tcp4", "127.0.0.1:0")
-	if err != nil {
-		return 0, err
-	}
-	l, err := net.ListenTCP("tcp4", lAddr0)
-	if err != nil {
-		return 0, err
-	}
-	defer l.Close()
-	lAddr := l.Addr()
-	lTCPAddr, ok := lAddr.(*net.TCPAddr)
-	if !ok {
-		return 0, fmt.Errorf("expected *net.TCPAddr, got %v", lAddr)
-	}
-	port := lTCPAddr.Port
-	if port <= 0 {
-		return 0, fmt.Errorf("unexpected port %d", port)
-	}
-	return port, nil
-}
-
-func findFreeUDPLocalPort() (int, error) {
-	lAddr0, err := net.ResolveUDPAddr("udp4", "127.0.0.1:0")
-	if err != nil {
-		return 0, err
-	}
-	l, err := net.ListenUDP("udp4", lAddr0)
-	if err != nil {
-		return 0, err
-	}
-	defer l.Close()
-	lAddr := l.LocalAddr()
-	lUDPAddr, ok := lAddr.(*net.UDPAddr)
-	if !ok {
-		return 0, fmt.Errorf("expected *net.UDPAddr, got %v", lAddr)
-	}
-	port := lUDPAddr.Port
-	if port <= 0 {
-		return 0, fmt.Errorf("unexpected port %d", port)
-	}
-	return port, nil
-}
-
 func (a *HostAgent) emitEvent(_ context.Context, ev events.Event) {
 	a.eventEncMu.Lock()
 	defer a.eventEncMu.Unlock()

pkg/hostagent/port_darwin.go

@@ -155,7 +155,3 @@ func (plf *pseudoLoopbackForwarder) Close() error {
 	_ = plf.ln.Close()
 	return plf.onClose()
 }
-
-func getFreeVSockPort() (int, error) {
-	return 0, nil
-}

pkg/hostagent/port_others.go

@@ -11,7 +11,3 @@ import (
 func forwardTCP(ctx context.Context, sshConfig *ssh.SSHConfig, port int, local, remote, verb string) error {
 	return forwardSSH(ctx, sshConfig, port, local, remote, verb, false)
 }
-
-func getFreeVSockPort() (int, error) {
-	return 0, nil
-}

pkg/hostagent/port_windows.go

@@ -3,14 +3,9 @@ package hostagent
 import (
 	"context"
 
-	"github.com/lima-vm/lima/pkg/windows"
 	"github.com/lima-vm/sshocker/pkg/ssh"
 )
 
 func forwardTCP(ctx context.Context, sshConfig *ssh.SSHConfig, port int, local, remote, verb string) error {
 	return forwardSSH(ctx, sshConfig, port, local, remote, verb, false)
 }
-
-func getFreeVSockPort() (int, error) {
-	return windows.GetRandomFreeVSockPort(0, 2147483647)
-}