kernel should be active long support version 4.19 or later.

Signed-off-by: Paco Xu <paco.xu@daocloud.io>

validators/kernel_validator.go

@@ -90,7 +90,7 @@ func (k *KernelValidator) validateKernelVersion(kSpec KernelSpec) error {
 		}
 	}
 	k.Reporter.Report("KERNEL_VERSION", k.kernelRelease, bad)
-	return fmt.Errorf("unsupported kernel release: %s", k.kernelRelease)
+	return fmt.Errorf("kernel release %s is unsupported. %s", k.kernelRelease, kSpec.VersionsNote)
 }
 
 // validateKernelConfig validates the kernel configurations.

validators/kernel_validator_test.go

@@ -31,20 +31,45 @@ 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\.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:     true,
+		},
+		{
+			name:    "4.7.1 no version regex matches",
+			version: "4.7.1",
+			err:     true,
+		},
+		{
+			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,
 		},
 		{
@@ -79,7 +104,7 @@ 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 +214,7 @@ 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 additional information 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 +28,9 @@ 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
+		// 4.19 is an active kernel Long Term Support (LTS) release, tracked in https://www.kernel.org/category/releases.html.
+		Versions:     []string{`^4\.19.*$`, `^4\.[2-9][0-9].*$`, `^([5-9]|[1-9][0-9]+)\.([0-9]+)\.([0-9]+).*$`},
+		VersionsNote: "Recommended LTS version from the 4.x series is 4.19. Any 5.x or 6.x versions are also supported. For cgroups v2 support, the minimal version is 4.15 and the recommended version is 5.8+",
 		// 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: "The kernel version should be >= '10.0.14393'",
+		Required:     []KernelConfig{},
+		Optional:     []KernelConfig{},
+		Forbidden:    []KernelConfig{},
 	},
 	RuntimeSpec: RuntimeSpec{
 		DockerSpec: &DockerSpec{