Revert "Deprecated --cleanup-ipvs flag in kube-proxy"

This reverts commit 4f1bb2bd2f.

cmd/kube-proxy/app/server.go

@@ -100,8 +100,10 @@ type Options struct {
 	ConfigFile string
 	// WriteConfigTo is the path where the default configuration will be written.
 	WriteConfigTo string
-	// CleanupAndExit, when true, makes the proxy server clean up iptables, ipvs, etc rules, then exit.
+	// CleanupAndExit, when true, makes the proxy server clean up iptables rules, then exit.
 	CleanupAndExit bool
+	// CleanupIPVS, when true, makes the proxy server clean up ipvs rules before running.
+	CleanupIPVS bool
 	// WindowsService should be set to true if kube-proxy is running as a service on Windows.
 	// Its corresponding flag only gets registered in Windows builds
 	WindowsService bool
@@ -141,7 +143,7 @@ func (o *Options) AddFlags(fs *pflag.FlagSet) {
 	fs.BoolVar(&o.CleanupAndExit, "cleanup-iptables", o.CleanupAndExit, "If true cleanup iptables and ipvs rules and exit.")
 	fs.MarkDeprecated("cleanup-iptables", "This flag is replaced by --cleanup.")
 	fs.BoolVar(&o.CleanupAndExit, "cleanup", o.CleanupAndExit, "If true cleanup iptables and ipvs rules and exit.")
-	fs.MarkDeprecated("cleanup-ipvs", "This flag is replaced by --cleanup.")
+	fs.BoolVar(&o.CleanupIPVS, "cleanup-ipvs", o.CleanupIPVS, "If true make kube-proxy cleanup ipvs rules before running.  Default is true")
 
 	// All flags below here are deprecated and will eventually be removed.
 
@@ -201,6 +203,7 @@ func NewOptions() *Options {
 		metricsPort: ports.ProxyStatusPort,
 		scheme:      scheme.Scheme,
 		codecs:      scheme.Codecs,
+		CleanupIPVS: true,
 		errCh:       make(chan error),
 	}
 }
@@ -496,6 +499,7 @@ type ProxyServer struct {
 	ProxyMode              string
 	NodeRef                *v1.ObjectReference
 	CleanupAndExit         bool
+	CleanupIPVS            bool
 	MetricsBindAddress     string
 	EnableProfiling        bool
 	OOMScoreAdj            *int32
@@ -553,7 +557,7 @@ func (s *ProxyServer) Run() error {
 	if s.CleanupAndExit {
 		encounteredError := userspace.CleanupLeftovers(s.IptInterface)
 		encounteredError = iptables.CleanupLeftovers(s.IptInterface) || encounteredError
-		encounteredError = ipvs.CleanupLeftovers(s.IpvsInterface, s.IptInterface, s.IpsetInterface) || encounteredError
+		encounteredError = ipvs.CleanupLeftovers(s.IpvsInterface, s.IptInterface, s.IpsetInterface, s.CleanupIPVS) || encounteredError
 		if encounteredError {
 			return errors.New("encountered an error while tearing down rules.")
 		}

pkg/proxy/ipvs/proxier.go

@@ -590,21 +590,22 @@ func cleanupIptablesLeftovers(ipt utiliptables.Interface) (encounteredError bool
 }
 
 // CleanupLeftovers clean up all ipvs and iptables rules created by ipvs Proxier.
-func CleanupLeftovers(ipvs utilipvs.Interface, ipt utiliptables.Interface, ipset utilipset.Interface) (encounteredError bool) {
-	// Return immediately when ipvs interface is nil - Probably initialization failed in somewhere.
-	if ipvs == nil {
-		return true
+func CleanupLeftovers(ipvs utilipvs.Interface, ipt utiliptables.Interface, ipset utilipset.Interface, cleanupIPVS bool) (encounteredError bool) {
+	if cleanupIPVS {
+		// Return immediately when ipvs interface is nil - Probably initialization failed in somewhere.
+		if ipvs == nil {
+			return true
+		}
+		encounteredError = false
+		err := ipvs.Flush()
+		if err != nil {
+			klog.Errorf("Error flushing IPVS rules: %v", err)
+			encounteredError = true
+		}
 	}
-	encounteredError = false
-	err := ipvs.Flush()
-	if err != nil {
-		klog.Errorf("Error flushing IPVS rules: %v", err)
-		encounteredError = true
-	}
-
 	// Delete dummy interface created by ipvs Proxier.
 	nl := NewNetLinkHandle(false)
-	err = nl.DeleteDummyDevice(DefaultDummyDevice)
+	err := nl.DeleteDummyDevice(DefaultDummyDevice)
 	if err != nil {
 		klog.Errorf("Error deleting dummy device %s created by IPVS proxier: %v", DefaultDummyDevice, err)
 		encounteredError = true