Fix crc-org#2131 Add preflight check for WSL2

This check looks at the kernel version string and determines if a
Microsoft compiled kernel is used, as is the case with WSL2. This is to
prevent a setup that uses Nested Virtualization.

pkg/crc/preflight/preflight_checks_linux.go

@@ -29,6 +29,20 @@ const (
 	minSupportedLibvirtVersion = "3.4.0"
 )
 
+func checkRunningInsideWSL2() error {
+	version, err := ioutil.ReadFile("/proc/version")
+	if err != nil {
+		return err
+	}
+
+	if strings.Contains(string(version), "Microsoft") {
+		logging.Debugf("Running inside WSL2 environment")
+		return fmt.Errorf("CodeReady Containers is unsupported using WSL2")
+	}
+
+	return nil
+}
+
 func checkVirtualizationEnabled() error {
 	logging.Debug("Checking if the vmx/svm flags are present in /proc/cpuinfo")
 	// Check if the cpu flags vmx or svm is present

pkg/crc/preflight/preflight_linux.go

@@ -17,6 +17,7 @@ import (
 
 func libvirtPreflightChecks(distro *linux.OsRelease) []Check {
 	checks := []Check{
+
 		{
 			configKeySuffix:  "check-virt-enabled",
 			checkDescription: "Checking if Virtualization is enabled",
@@ -114,6 +115,14 @@ var vsockPreflightChecks = Check{
 	cleanup:            removeVsockCrcSettings,
 }
 
+var wsl2PreflightChecks = Check{
+	configKeySuffix:  "check-wsl2",
+	checkDescription: "Checking if running inside WSL2",
+	check:            checkRunningInsideWSL2,
+	fixDescription:   "CodeReady Containers is unsupported using WSL2",
+	flags:            NoFix,
+}
+
 const (
 	vsockUdevSystemRulesPath     = "/usr/lib/udev/rules.d/99-crc-vsock.rules"
 	vsockUdevLocalAdminRulesPath = "/etc/udev/rules.d/99-crc-vsock.rules"
@@ -220,6 +229,7 @@ func removeVsockCrcSettings() error {
 func getAllPreflightChecks() []Check {
 	usingSystemdResolved := checkSystemdResolvedIsRunning()
 	checks := getPreflightChecksForDistro(distro(), network.DefaultMode, usingSystemdResolved == nil)
+	checks = append(checks, wsl2PreflightChecks)
 	checks = append(checks, vsockPreflightChecks)
 	return checks
 }