Merge pull request #4378 from SvenDowideit/default-to-external-switch

[hyperv] if no vswitch is specified, only pick the first external one

drivers/hyperv/hyperv.go

@@ -255,21 +255,29 @@ func (d *Driver) Create() error {
 }
 
 func (d *Driver) chooseVirtualSwitch() (string, error) {
-	stdout, err := cmdOut("(Get-VMSwitch).Name")
-	if err != nil {
-		return "", err
-	}
+	if d.VSwitch == "" {
+		// Default to the first external switche and in the process avoid DockerNAT
+		stdout, err := cmdOut("(Get-VMSwitch -SwitchType External).Name")
+		if err != nil {
+			return "", err
+		}
 
-	switches := parseLines(stdout)
+		switches := parseLines(stdout)
 
-	if d.VSwitch == "" {
 		if len(switches) < 1 {
-			return "", fmt.Errorf("no vswitch found. A valid vswitch must be available for this command to run. Check https://docs.docker.com/machine/drivers/hyper-v/")
+			return "", fmt.Errorf("no External vswitch found. A valid vswitch must be available for this command to run. Check https://docs.docker.com/machine/drivers/hyper-v/")
 		}
 
 		return switches[0], nil
 	}
 
+	stdout, err := cmdOut("(Get-VMSwitch).Name")
+	if err != nil {
+		return "", err
+	}
+
+	switches := parseLines(stdout)
+
 	found := false
 	for _, name := range switches {
 		if name == d.VSwitch {