Add failover flag (#216)

Signed-off-by: RainbowMango <renhongcai@huawei.com>

cmd/scheduler/app/options/options.go

@@ -29,6 +29,9 @@ type Options struct {
 	BindAddress string
 	// SecurePort is the port that the server serves at.
 	SecurePort int
+
+	// Failover indicates if scheduler should reschedule on cluster failure.
+	Failover bool
 }
 
 // NewOptions builds an default scheduler options.
@@ -56,4 +59,5 @@ func (o *Options) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&o.Master, "master", o.Master, "The address of the Kubernetes API server. Overrides any value in KubeConfig. Only required if out-of-cluster.")
 	fs.StringVar(&o.BindAddress, "bind-address", defaultBindAddress, "The IP address on which to listen for the --secure-port port.")
 	fs.IntVar(&o.SecurePort, "secure-port", defaultPort, "The secure port on which to serve HTTPS.")
+	fs.BoolVar(&o.Failover, "failover", false, "Reschedule on cluster failure.")
 }

cmd/scheduler/app/scheduler.go

@@ -60,6 +60,7 @@ func run(opts *options.Options, stopChan <-chan struct{}) error {
 		cancel()
 	}()
 
+	scheduler.Failover = opts.Failover
 	sched := scheduler.NewScheduler(dynamicClientSet, karmadaClient, kubeClientSet)
 	if !opts.LeaderElection.LeaderElect {
 		sched.Run(ctx)

pkg/scheduler/scheduler.go

@@ -40,6 +40,10 @@ const (
 	maxRetries = 15
 )
 
+// Failover indicates if the scheduler should performs re-scheduler in case of cluster failure.
+// TODO(RainbowMango): Remove the temporary solution by introducing feature flag
+var Failover bool
+
 // Scheduler is the scheduler schema, which is used to schedule a specific resource to specific clusters
 type Scheduler struct {
 	DynamicClient          dynamic.Interface
@@ -225,6 +229,7 @@ func (s *Scheduler) scheduleNext() bool {
 		return false
 	}
 	defer s.queue.Done(key)
+	klog.Infof("Failover flag is: %v", Failover)
 
 	err := s.scheduleOne(key.(string))
 	s.handleErr(err, key)