Adding documentation to the NFD controller resources file

Adding documentation describing the funcs, vars, etc. in the NFD
controller resources file so that users and contributors can
understand how they all work.

controllers/nodefeaturediscovery_resources.go

@@ -32,9 +32,13 @@ import (
 	"k8s.io/kubectl/pkg/scheme"
 )
 
+// assetsFromFile is a list where each item in the list contains the
+// contents of a given file as a list of bytes
 type assetsFromFile []byte
 
-// Resources holds objects owned by NFD
+// Resources holds objects owned by NFD. This struct is used with the
+// 'NFD' struct to assist in the process of checking if NFD's resources
+// are 'Ready' or 'NotReady'.
 type Resources struct {
 	Namespace                  corev1.Namespace
 	ServiceAccount             corev1.ServiceAccount
@@ -58,8 +62,17 @@ func Add3dpartyResourcesToScheme(scheme *runtime.Scheme) error {
 	return nil
 }
 
+// filePathWalkDir takes a path as an input and finds all files
+// in that path, but not directories
 func filePathWalkDir(root string) ([]string, error) {
+
+	// files contains the list of files found in the path
+	// 'root'
 	var files []string
+
+	// Walk through the files in 'path', and if the os.FileInfo object
+	// states that the item is not a directory, append it to the list
+	// of files
 	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
 		if !info.IsDir() {
 			files = append(files, path)
@@ -69,34 +82,66 @@ func filePathWalkDir(root string) ([]string, error) {
 	return files, err
 }
 
+// getAssetsFrom takes a path as an input and grabs all of the
+// file names in that path, then returns a list of the manifests
+// it found in that path.
 func getAssetsFrom(path string) []assetsFromFile {
 
+	// manifests is a list type where each item in the list
+	// contains the contents of a given asset (manifest)
 	manifests := []assetsFromFile{}
 	assets := path
+
+	// For the given path, find a list of all the files
 	files, err := filePathWalkDir(assets)
 	if err != nil {
 		panic(err)
 	}
+
+	// For each file in the 'files' list, read the file
+	// and store its contents in 'manifests'
 	for _, file := range files {
+
+		// Read the file and return its contents in 'buffer'
 		buffer, err := ioutil.ReadFile(file)
+
+		// If we have an error, then something unexpectedly went
+		// wrong when reading the file's contents
 		if err != nil {
 			panic(err)
 		}
+
+		// If the reading goes smoothly, then append the buffer
+		// (the file's contents) to the list of manifests
 		manifests = append(manifests, buffer)
 	}
 	return manifests
 }
 
+
 func addResourcesControls(path string) (Resources, controlFunc) {
+
+	// res is a Resources object that contains information about
+	// a given manifest, such as the Namespace and ServiceAccount
+	// being used
 	res := Resources{}
+
+	// ctrl is a controlFunc object that contains a function
+	// that returns information about the status of a resource
+	// (i.e., Ready or NotReady)
 	ctrl := controlFunc{}
 
+	// Get the list of manifests from the given path
 	manifests := getAssetsFrom(path)
 
+	// s and reg are used later on to parse the manifest YAML
 	s := json.NewYAMLSerializer(json.DefaultMetaFactory, scheme.Scheme,
 		scheme.Scheme)
 	reg, _ := regexp.Compile(`\b(\w*kind:\w*)\B.*\b`)
 
+	// For each manifest, find its kind, then append the appropriate
+	// function (e.g., 'Namespace' or 'Role') to ctrl so that the
+	// Namespace, Role, etc. can be parsed
 	for _, m := range manifests {
 		kind := reg.FindString(string(m))
 		slce := strings.Split(kind, ":")
@@ -153,6 +198,7 @@ func addResourcesControls(path string) (Resources, controlFunc) {
 	return res, ctrl
 }
 
+// Trigger a panic if an error occurs
 func panicIfError(err error) {
 	if err != nil {
 		panic(err)