nfd-master: add -featurerules-controller flag

Add a new command line flag for disabling/enabling the controller for
NodeFeatureRule objects. In practice, disabling the controller disables
all labels generated from rules in NodeFeatureRule objects.

cmd/nfd-master/main.go

@@ -96,6 +96,8 @@ func initFlags(flagset *flag.FlagSet) *master.Args {
 			"NB: the label namespace is omitted i.e. the filter is only applied to the name part after '/'.")
 	flagset.BoolVar(&args.NoPublish, "no-publish", false,
 		"Do not publish feature labels")
+	flagset.BoolVar(&args.FeatureRulesController, "featurerules-controller", true,
+		"Enable controller for NodeFeatureRule objects. Generates node labels based on the rules in these CRs.")
 	flagset.IntVar(&args.Port, "port", 8080,
 		"Port on which to listen for connections.")
 	flagset.BoolVar(&args.Prune, "prune", false,

deployment/helm/node-feature-discovery/templates/master.yaml

@@ -62,6 +62,7 @@ spec:
             {{- if .Values.master.extraLabelNs | empty | not }}
             - "--extra-label-ns={{- join "," .Values.master.extraLabelNs }}"
             {{- end }}
+            - "-featurerules-controller={{ .Values.master.featureRulesController }}"
 ## Enable TLS authentication
 ## The example below assumes having the root certificate named ca.crt stored in
 ## a ConfigMap named nfd-ca-cert, and, the TLS authentication credentials stored

deployment/helm/node-feature-discovery/values.yaml

@@ -24,6 +24,7 @@ nodeFeatureRule:
 master:
   instance:
   extraLabelNs: []
+  featureRulesController: true
 
   replicaCount: 1
 

docs/advanced/master-commandline-reference.md

@@ -151,6 +151,20 @@ Example:
 nfd-master -no-publish
 ```
 
+### -featurerules-controller
+
+The `-featurerules-controller` flag controlers the processing of
+NodeFeatureRule objects, effectively enabling/disabling labels from these
+custom labeling rules.
+
+Default: *true*
+
+Example:
+
+```bash
+nfd-master -featurerules-controller=false
+```
+
 ### -label-whitelist
 
 The `-label-whitelist` specifies a regular expression for filtering feature

docs/get-started/deployment-and-usage.md

@@ -299,6 +299,7 @@ We have introduced the following Chart parameters.
 | `master.*`                  | dict    |                                         | NFD master deployment configuration                                                                                                      |
 | `master.instance`           | string  |                                         | Instance name. Used to separate annotation namespaces for multiple parallel deployments                                                  |
 | `master.extraLabelNs`       | array   | []                                      | List of allowed extra label namespaces                                                                                                   |
+| `master.featureRulesController` | bool | True                                   | Specifies whether the controller for  processing of NodeFeatureRule objects is enable.                                                   |
 | `master.replicaCount`       | integer | 1                                       | Number of desired pods. This is a pointer to distinguish between explicit zero and not specified                                         |
 | `master.podSecurityContext` | dict    | {}                                      | SecurityContext holds pod-level security attributes and common container settings                                                        |
 | `master.service.type`       | string  | ClusterIP                               | NFD master service type                                                                                                                  |

pkg/nfd-master/nfd-master.go

@@ -83,18 +83,19 @@ type Annotations map[string]string
 
 // Args holds command line arguments
 type Args struct {
-	CaFile         string
-	CertFile       string
-	ExtraLabelNs   utils.StringSetVal
-	Instance       string
-	KeyFile        string
-	Kubeconfig     string
-	LabelWhiteList utils.RegexpVal
-	NoPublish      bool
-	Port           int
-	Prune          bool
-	VerifyNodeName bool
-	ResourceLabels utils.StringSetVal
+	CaFile                 string
+	CertFile               string
+	ExtraLabelNs           utils.StringSetVal
+	Instance               string
+	KeyFile                string
+	Kubeconfig             string
+	LabelWhiteList         utils.RegexpVal
+	FeatureRulesController bool
+	NoPublish              bool
+	Port                   int
+	Prune                  bool
+	VerifyNodeName         bool
+	ResourceLabels         utils.StringSetVal
 }
 
 type NfdMaster interface {
@@ -173,11 +174,13 @@ func (m *nfdMaster) Run() error {
 		return m.prune()
 	}
 
-	kubeconfig, err := m.getKubeconfig()
-	if err != nil {
-		return err
+	if m.args.FeatureRulesController {
+		kubeconfig, err := m.getKubeconfig()
+		if err != nil {
+			return err
+		}
+		m.nfdController = newNfdController(kubeconfig)
 	}
-	m.nfdController = newNfdController(kubeconfig)
 
 	if !m.args.NoPublish {
 		err := m.updateMasterNode()