Fix lint errors

Removal of io.go revealed new lint errors in pkg/util/io

pkg/util/io/BUILD

@@ -10,7 +10,6 @@ load(
 go_library(
     name = "go_default_library",
     srcs = ["writer.go"],
-    "//vendor/k8s.io/api/core/v1:go_default_library",
     tags = ["automanaged"],
     deps = ["//vendor/github.com/golang/glog:go_default_library"],
 )

pkg/util/io/writer.go

@@ -28,6 +28,7 @@ import (
 
 // Writer is an interface which allows to write data to a file.
 type Writer interface {
+	// WriteFile mimics ioutil.WriteFile.
 	WriteFile(filename string, data []byte, perm os.FileMode) error
 }
 
@@ -36,31 +37,32 @@ type Writer interface {
 type StdWriter struct {
 }
 
+// WriteFile directly calls ioutil.WriteFile.
 func (writer *StdWriter) WriteFile(filename string, data []byte, perm os.FileMode) error {
 	return ioutil.WriteFile(filename, data, perm)
 }
 
-// Alternative implementation of Writer interface that allows writing data to file
-// using nsenter command.
+// NsenterWriter is implementation of Writer interface that allows writing data
+// to file using nsenter command.
 // If a program (e.g. kubelet) runs in a container it may want to write data to
 // a mounted device. Since in Docker, mount propagation mode is set to private,
 // it will not see the mounted device in its own namespace. To work around this
-// limitaion one has to first enter hosts namespace (by using 'nsenter') and only
-// then write data.
-type NsenterWriter struct {
-}
+// limitation one has to first enter hosts namespace (by using 'nsenter') and
+// only then write data.
+type NsenterWriter struct{}
 
-// TODO: should take a writer, not []byte
+// WriteFile calls 'nsenter cat - > <the file>' and 'nsenter chmod' to create a
+// file on the host.
 func (writer *NsenterWriter) WriteFile(filename string, data []byte, perm os.FileMode) error {
 	cmd := "nsenter"
-	base_args := []string{
+	baseArgs := []string{
 		"--mount=/rootfs/proc/1/ns/mnt",
 		"--",
 	}
 
-	echo_args := append(base_args, "sh", "-c", fmt.Sprintf("cat > %s", filename))
-	glog.V(5).Infof("Command to write data to file: %v %v", cmd, echo_args)
-	command := exec.Command(cmd, echo_args...)
+	echoArgs := append(baseArgs, "sh", "-c", fmt.Sprintf("cat > %s", filename))
+	glog.V(5).Infof("Command to write data to file: %v %v", cmd, echoArgs)
+	command := exec.Command(cmd, echoArgs...)
 	command.Stdin = bytes.NewBuffer(data)
 	outputBytes, err := command.CombinedOutput()
 	if err != nil {
@@ -68,9 +70,9 @@ func (writer *NsenterWriter) WriteFile(filename string, data []byte, perm os.Fil
 		return err
 	}
 
-	chmod_args := append(base_args, "chmod", fmt.Sprintf("%o", perm), filename)
-	glog.V(5).Infof("Command to change permissions to file: %v %v", cmd, chmod_args)
-	outputBytes, err = exec.Command(cmd, chmod_args...).CombinedOutput()
+	chmodArgs := append(baseArgs, "chmod", fmt.Sprintf("%o", perm), filename)
+	glog.V(5).Infof("Command to change permissions to file: %v %v", cmd, chmodArgs)
+	outputBytes, err = exec.Command(cmd, chmodArgs...).CombinedOutput()
 	if err != nil {
 		glog.Errorf("Output from chmod command: %v", string(outputBytes))
 		return err