topology-updater: add kubelet-state-dir flag

On different Kubernetes flavors like OpenShift for exmaple,
the Kubelet state directory path is different. make it configurable
for maximum flexability.

Signed-off-by: Talor Itzhak <titzhak@redhat.com>

cmd/nfd-topology-updater/main.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"net/url"
 	"os"
+	"path"
 	"time"
 
 	"k8s.io/klog/v2"
@@ -40,6 +41,8 @@ const (
 	kubeletSecurePort = 10250
 )
 
+var DefaultKubeletStateDir = path.Join(string(hostpath.VarDir), "lib", "kubelet")
+
 func main() {
 	flags := flag.NewFlagSet(ProgramName, flag.ExitOnError)
 
@@ -140,6 +143,7 @@ func initFlags(flagset *flag.FlagSet) (*topology.Args, *resourcemonitor.Args) {
 	flagset.StringVar(&args.ConfigFile, "config", "/etc/kubernetes/node-feature-discovery/nfd-topology-updater.conf",
 		"Config file to use.")
 	flagset.BoolVar(&resourcemonitorArgs.PodSetFingerprint, "pods-fingerprint", false, "Compute and report the pod set fingerprint")
+	flagset.StringVar(&args.KubeletStateDir, "kubelet-state-dir", DefaultKubeletStateDir, "Kubelet state directory path for watching state and checkpoint files")
 
 	klog.InitFlags(flagset)
 

pkg/nfd-topology-updater/kubeletnotifier/kubeletnotifier.go

@@ -33,7 +33,6 @@ const (
 	FSUpdate      EventType = "fsUpdate"
 )
 
-// TODO make path configurable
 var stateFiles = sets.NewString(
 	"cpu_manager_state",
 	"memory_manager_state",

pkg/nfd-topology-updater/nfd-topology-updater.go

@@ -47,10 +47,11 @@ const (
 
 // Args are the command line arguments
 type Args struct {
-	NoPublish      bool
-	Oneshot        bool
-	KubeConfigFile string
-	ConfigFile     string
+	NoPublish       bool
+	Oneshot         bool
+	KubeConfigFile  string
+	ConfigFile      string
+	KubeletStateDir string
 
 	Klog map[string]*utils.KlogFlagVal
 }