Avoid net.UnixConn type assertions

Use `net.DialUnix` rather than `net.Dial` to avoid type assertion.

Extract netutil to house a new `DialUnix` that hides the messier
interface presented by the standard library.

Signed-off-by: Tamir Duberstein <tamird@gmail.com>

pkg/hostagent/hostagent.go

@@ -30,6 +30,7 @@ import (
 	"github.com/lima-vm/lima/pkg/hostagent/events"
 	"github.com/lima-vm/lima/pkg/identifierutil"
 	"github.com/lima-vm/lima/pkg/limayaml"
+	"github.com/lima-vm/lima/pkg/netutil"
 	"github.com/lima-vm/lima/pkg/networks"
 	"github.com/lima-vm/lima/pkg/osutil"
 	"github.com/lima-vm/lima/pkg/portfwd"
@@ -631,8 +632,7 @@ func (a *HostAgent) createConnection(ctx context.Context) (net.Conn, error) {
 	conn, err := a.driver.GuestAgentConn(ctx)
 	// default to forwarded sock
 	if conn == nil && err == nil {
-		var d net.Dialer
-		conn, err = d.DialContext(ctx, "unix", filepath.Join(a.instDir, filenames.GuestAgentSock))
+		conn, err = netutil.DialUnix("unix", filepath.Join(a.instDir, filenames.GuestAgentSock))
 	}
 	return conn, err
 }

pkg/hostagent/port_darwin.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"github.com/lima-vm/lima/pkg/bicopy"
+	"github.com/lima-vm/lima/pkg/netutil"
 	"github.com/lima-vm/lima/pkg/portfwd"
 	"github.com/lima-vm/sshocker/pkg/ssh"
 	"github.com/sirupsen/logrus"
@@ -43,7 +44,7 @@ func forwardTCP(ctx context.Context, sshConfig *ssh.SSHConfig, port int, local,
 	if verb == verbCancel {
 		plf, ok := pseudoLoopbackForwarders[local]
 		if ok {
-			localUnix := plf.unixAddr.Name
+			localUnix := plf.unixSock
 			_ = plf.Close()
 			delete(pseudoLoopbackForwarders, local)
 			if err := forwardSSH(ctx, sshConfig, port, localUnix, remote, verb, false); err != nil {
@@ -87,16 +88,11 @@ var pseudoLoopbackForwarders = make(map[string]*pseudoLoopbackForwarder)
 
 type pseudoLoopbackForwarder struct {
 	ln       *net.TCPListener
-	unixAddr *net.UnixAddr
+	unixSock string
 	onClose  func() error
 }
 
 func newPseudoLoopbackForwarder(localPort int, unixSock string) (*pseudoLoopbackForwarder, error) {
-	unixAddr, err := net.ResolveUnixAddr("unix", unixSock)
-	if err != nil {
-		return nil, err
-	}
-
 	// use "tcp" network to listen on both "tcp4" and "tcp6"
 	lnAddr, err := net.ResolveTCPAddr("tcp", fmt.Sprintf("0.0.0.0:%d", localPort))
 	if err != nil {
@@ -109,7 +105,7 @@ func newPseudoLoopbackForwarder(localPort int, unixSock string) (*pseudoLoopback
 
 	plf := &pseudoLoopbackForwarder{
 		ln:       ln,
-		unixAddr: unixAddr,
+		unixSock: unixSock,
 	}
 
 	return plf, nil
@@ -144,7 +140,7 @@ func (plf *pseudoLoopbackForwarder) Serve() error {
 
 func (plf *pseudoLoopbackForwarder) forward(ac *net.TCPConn) error {
 	defer ac.Close()
-	unixConn, err := net.DialUnix("unix", nil, plf.unixAddr)
+	unixConn, err := netutil.DialUnix("unix", plf.unixSock)
 	if err != nil {
 		return err
 	}

pkg/httpclientutil/httpclientutil_others.go

@@ -7,6 +7,8 @@ import (
 	"net"
 	"net/http"
 	"os"
+
+	"github.com/lima-vm/lima/pkg/netutil"
 )
 
 // NewHTTPClientWithSocketPath creates a client.
@@ -18,8 +20,7 @@ func NewHTTPClientWithSocketPath(socketPath string) (*http.Client, error) {
 	hc := &http.Client{
 		Transport: &http.Transport{
 			DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
-				var d net.Dialer
-				return d.DialContext(ctx, "unix", socketPath)
+				return netutil.DialUnix("unix", socketPath)
 			},
 		},
 	}

pkg/httpclientutil/httpclientutil_windows.go

@@ -5,6 +5,8 @@ import (
 	"net"
 	"net/http"
 	"os"
+
+	"github.com/lima-vm/lima/pkg/netutil"
 )
 
 // NewHTTPClientWithSocketPath creates a client.
@@ -17,8 +19,7 @@ func NewHTTPClientWithSocketPath(socketPath string) (*http.Client, error) {
 	hc := &http.Client{
 		Transport: &http.Transport{
 			DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
-				var d net.Dialer
-				return d.DialContext(ctx, "unix", socketPath)
+				return netutil.DialUnix("unix", socketPath)
 			},
 		},
 	}

pkg/netutil/netutil.go

@@ -0,0 +1,11 @@
+package netutil
+
+import "net"
+
+func DialUnix(network, address string) (*net.UnixConn, error) {
+	addr, err := net.ResolveUnixAddr(network, address)
+	if err != nil {
+		return nil, err
+	}
+	return net.DialUnix(network, nil, addr)
+}

pkg/networks/usernet/client.go

@@ -16,6 +16,7 @@ import (
 	"github.com/lima-vm/lima/pkg/driver"
 	"github.com/lima-vm/lima/pkg/httpclientutil"
 	"github.com/lima-vm/lima/pkg/limayaml"
+	"github.com/lima-vm/lima/pkg/netutil"
 	"github.com/lima-vm/lima/pkg/networks/usernet/dnshosts"
 )
 
@@ -140,7 +141,7 @@ func create(sock string, subnet net.IP, base string) *Client {
 	client := &http.Client{
 		Transport: &http.Transport{
 			DialContext: func(context.Context, string, string) (net.Conn, error) {
-				return net.Dial("unix", sock)
+				return netutil.DialUnix("unix", sock)
 			},
 		},
 	}

pkg/qemu/qemu_driver.go

@@ -22,6 +22,7 @@ import (
 	"github.com/digitalocean/go-qemu/qmp/raw"
 	"github.com/lima-vm/lima/pkg/driver"
 	"github.com/lima-vm/lima/pkg/limayaml"
+	"github.com/lima-vm/lima/pkg/netutil"
 	"github.com/lima-vm/lima/pkg/networks/usernet"
 	"github.com/lima-vm/lima/pkg/store"
 	"github.com/lima-vm/lima/pkg/store/filenames"
@@ -396,10 +397,8 @@ func (l *LimaQemuDriver) ListSnapshots(_ context.Context) (string, error) {
 	return List(qCfg, l.Instance.Status == store.StatusRunning)
 }
 
-func (l *LimaQemuDriver) GuestAgentConn(ctx context.Context) (net.Conn, error) {
-	var d net.Dialer
-	dialContext, err := d.DialContext(ctx, "unix", filepath.Join(l.Instance.Dir, filenames.GuestAgentSock))
-	return dialContext, err
+func (l *LimaQemuDriver) GuestAgentConn(context.Context) (net.Conn, error) {
+	return netutil.DialUnix("unix", filepath.Join(l.Instance.Dir, filenames.GuestAgentSock))
 }
 
 type qArgTemplateApplier struct {
@@ -417,11 +416,7 @@ func (a *qArgTemplateApplier) applyTemplate(qArg string) (string, error) {
 				if !ok {
 					return "", fmt.Errorf("non-string argument %+v", v)
 				}
-				addr := &net.UnixAddr{
-					Net:  "unix",
-					Name: s,
-				}
-				conn, err := net.DialUnix("unix", nil, addr)
+				conn, err := netutil.DialUnix("unix", s)
 				if err != nil {
 					return "", err
 				}

pkg/vz/network_darwin.go

@@ -13,12 +13,13 @@ import (
 	"time"
 
 	"github.com/balajiv113/fd"
+	"github.com/lima-vm/lima/pkg/netutil"
 
 	"github.com/sirupsen/logrus"
 )
 
 func PassFDToUnix(unixSock string) (*os.File, error) {
-	unixConn, err := net.Dial("unix", unixSock)
+	unixConn, err := netutil.DialUnix("unix", unixSock)
 	if err != nil {
 		return nil, err
 	}
@@ -27,7 +28,7 @@ func PassFDToUnix(unixSock string) (*os.File, error) {
 	if err != nil {
 		return nil, err
 	}
-	err = fd.Put(unixConn.(*net.UnixConn), server)
+	err = fd.Put(unixConn, server)
 	if err != nil {
 		return nil, err
 	}
@@ -37,7 +38,7 @@ func PassFDToUnix(unixSock string) (*os.File, error) {
 // DialQemu support connecting to QEMU supported network stack via unix socket.
 // Returns os.File, connected dgram connection to be used for vz.
 func DialQemu(unixSock string) (*os.File, error) {
-	unixConn, err := net.Dial("unix", unixSock)
+	unixConn, err := netutil.DialUnix("unix", unixSock)
 	if err != nil {
 		return nil, err
 	}