auto select network on QEMU

Author: spowelljr

cmd/minikube/cmd/start_flags.go

@@ -463,14 +463,31 @@ func getNetwork(driverName string) string {
 	if !driver.IsQEMU(driverName) {
 		return n
 	}
-	if n == "" {
-		if runtime.GOOS == "darwin" {
-			out.WarningT("The default network for QEMU will change from 'user' to 'socket_vmnet' in a future release")
+	switch n {
+	case "socket_vmnet":
+		if runtime.GOOS != "darwin" {
+			exit.Message(reason.Usage, "The socket_vmnet network is only supported on macOS")
+		}
+		if !detect.SocketVMNetInstalled() {
+			exit.Message(reason.NotFoundSocketVMNet, "\n\n")
+		}
+	case "":
+		if detect.SocketVMNetInstalled() {
+			n = "socket_vmnet"
+		} else {
+			n = "user"
 		}
-		n = "user"
+		out.Styled(style.Internet, "Automatically selected the {{.network}} network", out.V{"network": n})
+	case "user":
+	default:
+		exit.Message(reason.Usage, "--network with QEMU must be 'user' or 'socket_vmnet'")
 	}
-	if n == "user" && runtime.GOOS == "darwin" {
-		out.WarningT("You are using the QEMU driver without a dedicated network, which doesn't support `minikube service` & `minikube tunnel` commands.\nTo try the experimental dedicated network see: https://minikube.sigs.k8s.io/docs/drivers/qemu/#networking")
+	if n == "user" {
+		msg := "You are using the QEMU driver without a dedicated network, which doesn't support `minikube service` & `minikube tunnel` commands."
+		if runtime.GOOS == "darwin" {
+			msg += "\nTo try the experimental dedicated network see: https://minikube.sigs.k8s.io/docs/drivers/qemu/#networking"
+		}
+		out.WarningT(msg)
 	}
 	return n
 }
@@ -489,10 +506,6 @@ func generateNewConfigFromFlags(cmd *cobra.Command, k8sVersion string, rtime str
 		out.WarningT("--network flag is only valid with the docker/podman, KVM and Qemu drivers, it will be ignored")
 	}
 
-	if driver.IsQEMU(drvName) && viper.GetString(network) == "socket_vmnet" {
-		out.WarningT("Using qemu with 'socket_vmnet' network is experimental")
-	}
-
 	checkNumaCount(k8sVersion)
 
 	checkExtraDiskOptions(cmd, drvName)

pkg/minikube/detect/detect.go

@@ -17,6 +17,7 @@ limitations under the License.
 package detect
 
 import (
+	"errors"
 	"net/http"
 	"os"
 	"os/exec"
@@ -25,7 +26,9 @@ import (
 	"strings"
 
 	"github.com/klauspost/cpuid"
+	"github.com/spf13/viper"
 	"golang.org/x/sys/cpu"
+	"k8s.io/klog/v2"
 	"k8s.io/minikube/pkg/minikube/localpath"
 )
 
@@ -129,3 +132,18 @@ func KICCacheDir() string {
 func ISOCacheDir() string {
 	return filepath.Join(localpath.MakeMiniPath("cache", "iso"), runtime.GOARCH)
 }
+
+// SocketVMNetInstalled returns if socket_vmnet is installed
+func SocketVMNetInstalled() bool {
+	if runtime.GOOS != "darwin" {
+		return false
+	}
+	_, err := os.Stat(viper.GetString("socket-vmnet-path"))
+	if err == nil {
+		return true
+	}
+	if !errors.Is(err, os.ErrNotExist) {
+		klog.Warningf("failed to check for socket_vmnet: %v", err)
+	}
+	return false
+}

pkg/minikube/reason/reason.go

@@ -483,4 +483,18 @@ var (
 		https://docs.docker.com/engine/install/`),
 		Style: style.Docker,
 	}
+	NotFoundSocketVMNet = Kind{
+		ID:       "NOT_FOUND_SOCKET_VMNET",
+		ExitCode: ExProgramNotFound,
+		Advice: translate.T(`socket_vmnet was not found on the system, resolve by:
+
+		Option 1) Installing socket_vmnet:
+
+		  https://minikube.sigs.k8s.io/docs/drivers/qemu/#networking
+
+		Option 2) Using the user network:
+
+		  minikube start{{.profile}} --driver qemu --network user`),
+		Style: style.SeeNoEvil,
+	}
 )