cgroup v2: add warning message for kernel < 5.8; add error message if…

… kernel < 4.15

validators/kernel_validator.go

@@ -67,7 +67,8 @@ func (k *KernelValidator) Validate(spec SysSpec) ([]error, []error) {
 	}
 	k.kernelRelease = release
 	var errs []error
-	if err = k.validateKernelVersion(spec.KernelSpec); err != nil {
+	err = k.validateKernelVersion(spec.KernelSpec)
+	if err != nil {
 		errs = append(errs, err)
 	}
 	// only validate kernel config when necessary (currently no kernel config for windows)
@@ -80,17 +81,20 @@ func (k *KernelValidator) Validate(spec SysSpec) ([]error, []error) {
 }
 
 // validateKernelVersion validates the kernel version.
-func (k *KernelValidator) validateKernelVersion(kSpec KernelSpec) error {
-	versionRegexps := kSpec.Versions
-	for _, versionRegexp := range versionRegexps {
+func (k *KernelValidator) validateKernelVersion(kSpec KernelSpec) (err error) {
+	var matched bool
+	for _, versionRegexp := range kSpec.Versions {
 		r := regexp.MustCompile(versionRegexp)
 		if r.MatchString(k.kernelRelease) {
-			k.Reporter.Report("KERNEL_VERSION", k.kernelRelease, good)
-			return nil
+			matched = true
+			break
 		}
 	}
-	k.Reporter.Report("KERNEL_VERSION", k.kernelRelease, bad)
-	return fmt.Errorf("unsupported kernel release: %s", k.kernelRelease)
+	if !matched {
+		err = fmt.Errorf("unsupported kernel release: %s", k.kernelRelease)
+		k.Reporter.Report("KERNEL_VERSION", k.kernelRelease, good)
+	}
+	return
 }
 
 // validateKernelConfig validates the kernel configurations.

validators/kernel_validator_test.go

@@ -31,22 +31,42 @@ func TestValidateKernelVersion(t *testing.T) {
 	// they may be different.
 	// This is fine, because the test mainly tests the kernel version validation logic,
 	// not the DefaultSysSpec. The DefaultSysSpec should be tested with node e2e.
-	testRegex := []string{`^3\.[1-9][0-9].*$`, `^([4-9]|[1-9][0-9]+)\.([0-9]+)\.([0-9]+).*$`}
+	testRegex := []string{`^4\.4.*$`, `^4\.19.*$`, `^4\.[2-9][0-9].*$`, `^([5-9]|[1-9][0-9]+)\.([0-9]+)\.([0-9]+).*$`}
 	for _, test := range []struct {
 		name    string
 		version string
 		err     bool
 	}{
 		{
-			name:    "3.19.9-99-test first version regex matches",
+			name:    "3.19.9-99-test no version regex matches",
 			version: "3.19.9-99-test",
-			err:     false,
+			err:     true,
 		},
 		{
-			name:    "4.4.14+ one of version regexes matches",
+			name:    "4.4.14+ no version regex matches",
 			version: "4.4.14+",
 			err:     false,
 		},
+		{
+			name:    "4.17.3 no version regex matches",
+			version: "4.17.3",
+			err:     true,
+		},
+		{
+			name:    "4.19.3-99-test matches",
+			version: "4.19.3-99-test",
+			err:     false,
+		},
+		{
+			name:    "4.20.3+ matches",
+			version: "4.20.3+",
+			err:     false,
+		},
+		{
+			name:    "5.12.3 matches",
+			version: "5.12.3",
+			err:     false,
+		},
 		{
 			name:    "2.0.0 no version regex matches",
 			version: "2.0.0",
@@ -79,7 +99,7 @@ func TestValidateKernelVersion(t *testing.T) {
 			if !test.err {
 				assert.Nil(t, err, "Expect error not to occur with kernel version %q", test.version)
 			} else {
-				assert.NotNil(t, err, "Expect error to occur with kenrel version %q", test.version)
+				assert.NotNil(t, err, "Expect error to occur with kernel version %q", test.version)
 			}
 		})
 	}
@@ -189,7 +209,7 @@ func TestValidateCachedKernelConfig(t *testing.T) {
 			if !test.err {
 				assert.Nil(t, err, "Expect error not to occur with kernel config %q", test.config)
 			} else {
-				assert.NotNil(t, err, "Expect error to occur with kenrel config %q", test.config)
+				assert.NotNil(t, err, "Expect error to occur with kernel config %q", test.config)
 			}
 		})
 	}

validators/types.go

@@ -42,6 +42,8 @@ type KernelConfig struct {
 type KernelSpec struct {
 	// Versions define supported kernel version. It is a group of regexps.
 	Versions []string `json:"versions,omitempty"`
+	// VersionsNote provides a prompt message for user if Versions do not match.
+	VersionsNote string `json:"versionsNote,omitempty"`
 	// Required contains all kernel configurations required to be enabled
 	// (built in or as module).
 	Required []KernelConfig `json:"required,omitempty"`

validators/types_unix.go

@@ -28,7 +28,10 @@ import (
 var DefaultSysSpec = SysSpec{
 	OS: "Linux",
 	KernelSpec: KernelSpec{
-		Versions: []string{`^3\.[1-9][0-9].*$`, `^([4-9]|[1-9][0-9]+)\.([0-9]+)\.([0-9]+).*$`}, // Requires 3.10+, or newer
+		// 4.4 & 4.19 are selected as kernel Super Long Term Support (SLTS), and the Civil Infrastructure Platform will provide support until at least 2026.
+		// For cgroup v2, Kubernetes recommends to use 5.8 and later, and in runc docs, the minimal version is 4.15 and 5.2+ is recommended.
+		Versions:     []string{`^4\.4.*$`, `^4\.19.*$`, `^4\.[2-9][0-9].*$`, `^([5-9]|[1-9][0-9]+)\.([0-9]+)\.([0-9]+).*$`}, // Requires 5.8+, or newer for cgroup v2
+		VersionsNote: "kernel version should be in maintenance, at least 4.4 or 4.19+, and to use cgroup v2, 5.8+ is recommended.",
 		// TODO(random-liu): Add more config
 		// TODO(random-liu): Add description for each kernel configuration:
 		Required: []KernelConfig{

validators/types_windows.go

@@ -28,10 +28,11 @@ import (
 var DefaultSysSpec = SysSpec{
 	OS: "Microsoft Windows Server 2016",
 	KernelSpec: KernelSpec{
-		Versions:  []string{`10\.0\.1439[3-9]`, `10\.0\.14[4-9][0-9]{2}`, `10\.0\.1[5-9][0-9]{3}`, `10\.0\.[2-9][0-9]{4}`, `10\.[1-9]+\.[0-9]+`}, //requires >= '10.0.14393'
-		Required:  []KernelConfig{},
-		Optional:  []KernelConfig{},
-		Forbidden: []KernelConfig{},
+		Versions:     []string{`10\.0\.1439[3-9]`, `10\.0\.14[4-9][0-9]{2}`, `10\.0\.1[5-9][0-9]{3}`, `10\.0\.[2-9][0-9]{4}`, `10\.[1-9]+\.[0-9]+`}, //requires >= '10.0.14393'
+		VersionsNote: "kernel version should>= '10.0.14393'",
+		Required:     []KernelConfig{},
+		Optional:     []KernelConfig{},
+		Forbidden:    []KernelConfig{},
 	},
 	RuntimeSpec: RuntimeSpec{
 		DockerSpec: &DockerSpec{