cluster-scope.go

// check the WATCH_NAMESPACE env var to see if populated
var watchNamespaceEnvVar = "WATCH_NAMESPACE"
watchNamespace, found := os.LookupEnv(watchNamespaceEnvVar)
if !found {
   return "", fmt.Errorf("%s must be set", watchNamespaceEnvVar)
}
mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
    Scheme:             scheme,
    MetricsBindAddress: metricsAddr,
    Port:               9443,
    LeaderElection:     enableLeaderElection,
    LeaderElectionID:   "f1c5ece8.example.com",
    Namespace:          watchNamespace, // namespaced-scope when the value is not an empty string
})