kube-proxy iptables min-sync-period default 1sec

Currently kube-proxy defaults the min-sync-period for
iptables to 0. However, as explained by Dan Winship,

"With minSyncPeriod: 0, you run iptables-restore 100 times.
 With minSyncPeriod: 1s , you run iptables-restore once.
 With minSyncPeriod: 10s , you also run iptables-restore once,
 but you might have to wait 10 seconds first"

Author: aojea

pkg/proxy/apis/config/scheme/testdata/KubeProxyConfiguration/after/v1alpha1.yaml

@@ -21,7 +21,7 @@ hostnameOverride: ""
 iptables:
   masqueradeAll: false
   masqueradeBit: 14
-  minSyncPeriod: 0s
+  minSyncPeriod: 1s
   syncPeriod: 30s
 ipvs:
   excludeCIDRs: null

pkg/proxy/apis/config/scheme/testdata/KubeProxyConfiguration/roundtrip/default/v1alpha1.yaml

@@ -21,7 +21,7 @@ hostnameOverride: ""
 iptables:
   masqueradeAll: false
   masqueradeBit: 14
-  minSyncPeriod: 0s
+  minSyncPeriod: 1s
   syncPeriod: 30s
 ipvs:
   excludeCIDRs: null

pkg/proxy/apis/config/v1alpha1/defaults.go

@@ -61,6 +61,9 @@ func SetDefaults_KubeProxyConfiguration(obj *kubeproxyconfigv1alpha1.KubeProxyCo
 	if obj.IPTables.SyncPeriod.Duration == 0 {
 		obj.IPTables.SyncPeriod = metav1.Duration{Duration: 30 * time.Second}
 	}
+	if obj.IPTables.MinSyncPeriod.Duration == 0 {
+		obj.IPTables.MinSyncPeriod = metav1.Duration{Duration: 1 * time.Second}
+	}
 	if obj.IPVS.SyncPeriod.Duration == 0 {
 		obj.IPVS.SyncPeriod = metav1.Duration{Duration: 30 * time.Second}
 	}