fix golint failures in cmd/kubeadm/app/util/system

cmd/kubeadm/app/util/system/cgroup_validator.go

@@ -26,10 +26,12 @@ import (
 
 var _ Validator = &CgroupsValidator{}
 
+// CgroupsValidator validates cgroup configuration.
 type CgroupsValidator struct {
 	Reporter Reporter
 }
 
+// Name is part of the system.Validator interface.
 func (c *CgroupsValidator) Name() string {
 	return "cgroups"
 }
@@ -38,6 +40,7 @@ const (
 	cgroupsConfigPrefix = "CGROUPS_"
 )
 
+// Validate is part of the system.Validator interface.
 func (c *CgroupsValidator) Validate(spec SysSpec) (error, error) {
 	subsystems, err := c.getCgroupSubsystems()
 	if err != nil {

cmd/kubeadm/app/util/system/docker_validator.go

@@ -32,6 +32,7 @@ type DockerValidator struct {
 	Reporter Reporter
 }
 
+// Name is part of the system.Validator interface.
 func (d *DockerValidator) Name() string {
 	return "docker"
 }
@@ -41,6 +42,7 @@ const (
 	latestValidatedDockerVersion = "18.09"
 )
 
+// Validate is part of the system.Validator interface.
 // TODO(random-liu): Add more validating items.
 func (d *DockerValidator) Validate(spec SysSpec) (error, error) {
 	if spec.RuntimeSpec.DockerSpec == nil {

cmd/kubeadm/app/util/system/kernel_validator.go

@@ -44,6 +44,7 @@ type KernelValidator struct {
 	Reporter      Reporter
 }
 
+// Name is part of the system.Validator interface.
 func (k *KernelValidator) Name() string {
 	return "kernel"
 }
@@ -58,10 +59,11 @@ const (
 
 	// validKConfigRegex is the regex matching kernel configuration line.
 	validKConfigRegex = "^CONFIG_[A-Z0-9_]+=[myn]"
-	// kConfigPrefix is the prefix of kernel configuration.
+	// kernelConfigPrefix is the prefix of kernel configuration.
-	kConfigPrefix = "CONFIG_"
+	kernelConfigPrefix = "CONFIG_"
 )
 
+// Validate is part of the system.Validator interface.
 func (k *KernelValidator) Validate(spec SysSpec) (error, error) {
 	helper := KernelValidatorHelperImpl{}
 	release, err := helper.GetKernelReleaseVersion()
@@ -135,7 +137,7 @@ func (k *KernelValidator) validateCachedKernelConfig(allConfig map[string]kConfi
 		var opt kConfigOption
 		var ok bool
 		for _, name = range append([]string{config.Name}, config.Aliases...) {
-			name = kConfigPrefix + name
+			name = kernelConfigPrefix + name
 			if opt, ok = allConfig[name]; ok {
 				break
 			}

cmd/kubeadm/app/util/system/kernel_validator_test.go

@@ -173,7 +173,7 @@ func TestValidateCachedKernelConfig(t *testing.T) {
 			// Add kernel config prefix.
 			for k, v := range test.config {
 				delete(test.config, k)
-				test.config[kConfigPrefix+k] = v
+				test.config[kernelConfigPrefix+k] = v
 			}
 			err := v.validateCachedKernelConfig(test.config, testKernelSpec)
 			if !test.err {

cmd/kubeadm/app/util/system/os_validator.go

@@ -25,14 +25,17 @@ import (
 
 var _ Validator = &OSValidator{}
 
+// OSValidator validates OS.
 type OSValidator struct {
 	Reporter Reporter
 }
 
+// Name is part of the system.Validator interface.
 func (o *OSValidator) Name() string {
 	return "os"
 }
 
+// Validate is part of the system.Validator interface.
 func (o *OSValidator) Validate(spec SysSpec) (error, error) {
 	os, err := exec.Command("uname").CombinedOutput()
 	if err != nil {

cmd/kubeadm/app/util/system/report.go

@@ -47,12 +47,13 @@ func colorize(s string, c color) string {
 	return fmt.Sprintf("\033[0;%dm%s\033[0m", c, s)
 }
 
-// The default reporter for the system verification test
+// StreamReporter is the default reporter for the system verification test.
 type StreamReporter struct {
 	// The stream that this reporter is writing to
 	WriteStream io.Writer
 }
 
+// Report reports validation result in different color depending on the result type.
 func (dr *StreamReporter) Report(key, value string, resultType ValidationResultType) error {
 	var c color
 	switch resultType {

hack/.golint_failures

@@ -3,7 +3,6 @@ cmd/kube-apiserver/app
 cmd/kube-controller-manager/app
 cmd/kube-proxy/app
 cmd/kubeadm/app/apis/kubeadm/v1beta1
-cmd/kubeadm/app/util/system
 pkg/apis/abac/latest
 pkg/apis/admission
 pkg/apis/admissionregistration