nfd-master: add --kubeconfig flag

Useful with --prune and for development purposes.

cmd/nfd-master/main.go

@@ -66,6 +66,7 @@ func argsParse(argv []string) (master.Args, error) {
   %s [--prune] [--no-publish] [--label-whitelist=<pattern>] [--port=<port>]
      [--ca-file=<path>] [--cert-file=<path>] [--key-file=<path>]
      [--verify-node-name] [--extra-label-ns=<list>] [--resource-labels=<list>]
+     [--kubeconfig=<path>]
   %s -h | --help
   %s --version
 
@@ -74,6 +75,8 @@ func argsParse(argv []string) (master.Args, error) {
   --version                       Output version and exit.
   --prune                         Prune all NFD related attributes from all nodes
                                   of the cluster and exit.
+  --kubeconfig=<path>             Kubeconfig to use [Default: ]
+                                  of the cluster and exit.
   --port=<port>                   Port on which to listen for connections.
                                   [Default: 8080]
   --ca-file=<path>                Root certificate for verifying connections
@@ -122,6 +125,7 @@ func argsParse(argv []string) (master.Args, error) {
 	args.ExtraLabelNs = strings.Split(arguments["--extra-label-ns"].(string), ",")
 	args.ResourceLabels = strings.Split(arguments["--resource-labels"].(string), ",")
 	args.Prune = arguments["--prune"].(bool)
+	args.Kubeconfig = arguments["--kubeconfig"].(string)
 
 	return args, nil
 }

pkg/apihelper/k8shelpers.go

@@ -24,18 +24,28 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	k8sclient "k8s.io/client-go/kubernetes"
 	restclient "k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
 )
 
 // Implements APIHelpers
 type K8sHelpers struct {
+	Kubeconfig string
 }
 
 func (h K8sHelpers) GetClient() (*k8sclient.Clientset, error) {
 	// Set up an in-cluster K8S client.
-	config, err := restclient.InClusterConfig()
+	var config *restclient.Config
+	var err error
+
+	if h.Kubeconfig == "" {
+		config, err = restclient.InClusterConfig()
+	} else {
+		config, err = clientcmd.BuildConfigFromFlags("", h.Kubeconfig)
+	}
 	if err != nil {
 		return nil, err
 	}
+
 	clientset, err := k8sclient.NewForConfig(config)
 	if err != nil {
 		return nil, err

pkg/nfd-master/nfd-master.go

@@ -70,6 +70,7 @@ type Args struct {
 	CertFile       string
 	ExtraLabelNs   []string
 	KeyFile        string
+	Kubeconfig     string
 	LabelWhiteList *regexp.Regexp
 	NoPublish      bool
 	Port           int
@@ -124,7 +125,7 @@ func NewNfdMaster(args Args) (NfdMaster, error) {
 	}
 
 	// Initialize Kubernetes API helpers
-	nfd.apihelper = apihelper.K8sHelpers{}
+	nfd.apihelper = apihelper.K8sHelpers{Kubeconfig: args.Kubeconfig}
 
 	return nfd, nil
 }