Drop broken/no-op proxyconfig.EndpointsHandler implementations

Because the proxy.Provider interface included
proxyconfig.EndpointsHandler, all the backends needed to
implement its methods. But iptables, ipvs, and winkernel implemented
them as no-ops, and metaproxier had an implementation that wouldn't
actually work (because it couldn't handle Services with no active
Endpoints).

Since Endpoints processing in kube-proxy is deprecated (and can't be
re-enabled unless you're using a backend that doesn't support
EndpointSlice), remove proxyconfig.EndpointsHandler from the
definition of proxy.Provider and drop all the useless implementations.

cmd/kube-proxy/app/server.go

@@ -751,14 +751,14 @@ func (s *ProxyServer) Run() error {
 	serviceConfig.RegisterEventHandler(s.Proxier)
 	go serviceConfig.Run(wait.NeverStop)
 
-	if s.UseEndpointSlices {
+	if endpointsHandler, ok := s.Proxier.(config.EndpointsHandler); ok && !s.UseEndpointSlices {
+		endpointsConfig := config.NewEndpointsConfig(informerFactory.Core().V1().Endpoints(), s.ConfigSyncPeriod)
+		endpointsConfig.RegisterEventHandler(endpointsHandler)
+		go endpointsConfig.Run(wait.NeverStop)
+	} else {
 		endpointSliceConfig := config.NewEndpointSliceConfig(informerFactory.Discovery().V1().EndpointSlices(), s.ConfigSyncPeriod)
 		endpointSliceConfig.RegisterEventHandler(s.Proxier)
 		go endpointSliceConfig.Run(wait.NeverStop)
-	} else {
-		endpointsConfig := config.NewEndpointsConfig(informerFactory.Core().V1().Endpoints(), s.ConfigSyncPeriod)
-		endpointsConfig.RegisterEventHandler(s.Proxier)
-		go endpointsConfig.Run(wait.NeverStop)
 	}
 
 	// This has to start after the calls to NewServiceConfig and NewEndpointsConfig because those

pkg/proxy/config/config.go

@@ -47,7 +47,9 @@ type ServiceHandler interface {
 }
 
 // EndpointsHandler is an abstract interface of objects which receive
-// notifications about endpoints object changes.
+// notifications about endpoints object changes. This is not a required
+// sub-interface of proxy.Provider, and proxy implementations should
+// not implement it unless they can't handle EndpointSlices.
 type EndpointsHandler interface {
 	// OnEndpointsAdd is called whenever creation of new endpoints object
 	// is observed.

pkg/proxy/iptables/proxier.go

@@ -579,25 +579,6 @@ func (proxier *Proxier) OnServiceSynced() {
 	proxier.syncProxyRules()
 }
 
-// iptables proxier only uses EndpointSlice, the following methods
-// exist to implement the Proxier interface but are noops
-
-// OnEndpointsAdd is called whenever creation of new endpoints object
-// is observed.
-func (proxier *Proxier) OnEndpointsAdd(endpoints *v1.Endpoints) {}
-
-// OnEndpointsUpdate is called whenever modification of an existing
-// endpoints object is observed.
-func (proxier *Proxier) OnEndpointsUpdate(oldEndpoints, endpoints *v1.Endpoints) {}
-
-// OnEndpointsDelete is called whenever deletion of an existing endpoints
-// object is observed.
-func (proxier *Proxier) OnEndpointsDelete(endpoints *v1.Endpoints) {}
-
-// OnEndpointsSynced is called once all the initial event handlers were
-// called and the state is fully propagated to local cache.
-func (proxier *Proxier) OnEndpointsSynced() {}
-
 // OnEndpointSliceAdd is called whenever creation of a new endpoint slice object
 // is observed.
 func (proxier *Proxier) OnEndpointSliceAdd(endpointSlice *discovery.EndpointSlice) {

pkg/proxy/iptables/proxier_test.go

@@ -2883,7 +2883,6 @@ COMMIT
 	ipt := iptablestest.NewFake()
 	fp := NewFakeProxier(ipt)
 	fp.OnServiceSynced()
-	fp.OnEndpointsSynced()
 	fp.OnEndpointSlicesSynced()
 
 	serviceName := "svc1"
@@ -2992,7 +2991,6 @@ COMMIT
 	ipt := iptablestest.NewFake()
 	fp := NewFakeProxier(ipt)
 	fp.OnServiceSynced()
-	fp.OnEndpointsSynced()
 	fp.OnEndpointSlicesSynced()
 
 	serviceName := "svc1"
@@ -3056,7 +3054,6 @@ func Test_HealthCheckNodePortWhenTerminating(t *testing.T) {
 	ipt := iptablestest.NewFake()
 	fp := NewFakeProxier(ipt)
 	fp.OnServiceSynced()
-	fp.OnEndpointsSynced()
 	fp.OnEndpointSlicesSynced()
 
 	serviceName := "svc1"
@@ -3551,7 +3548,6 @@ COMMIT
 		ipt := iptablestest.NewFake()
 		fp := NewFakeProxier(ipt)
 		fp.OnServiceSynced()
-		fp.OnEndpointsSynced()
 		fp.OnEndpointSlicesSynced()
 
 		serviceName := "svc1"
@@ -4139,7 +4135,6 @@ COMMIT
 			ipt := iptablestest.NewFake()
 			fp := NewFakeProxier(ipt)
 			fp.OnServiceSynced()
-			fp.OnEndpointsSynced()
 			fp.OnEndpointSlicesSynced()
 
 			fp.OnServiceAdd(testcase.service)

pkg/proxy/ipvs/proxier.go

@@ -891,21 +891,6 @@ func (proxier *Proxier) OnServiceSynced() {
 	proxier.syncProxyRules()
 }
 
-// The following methods exist to implement the Proxier interface however
-// ipvs proxier only uses EndpointSlices so the following are noops
-
-// OnEndpointsAdd is called whenever creation of new endpoints object is observed.
-func (proxier *Proxier) OnEndpointsAdd(endpoints *v1.Endpoints) {}
-
-// OnEndpointsUpdate is called whenever modification of an existing endpoints object is observed.
-func (proxier *Proxier) OnEndpointsUpdate(oldEndpoints, endpoints *v1.Endpoints) {}
-
-// OnEndpointsDelete is called whenever deletion of an existing endpoints object is observed.
-func (proxier *Proxier) OnEndpointsDelete(endpoints *v1.Endpoints) {}
-
-// OnEndpointsSynced is called once all the initial event handlers were called and the state is fully propagated to local cache.
-func (proxier *Proxier) OnEndpointsSynced() {}
-
 // OnEndpointSliceAdd is called whenever creation of a new endpoint slice object
 // is observed.
 func (proxier *Proxier) OnEndpointSliceAdd(endpointSlice *discovery.EndpointSlice) {

pkg/proxy/metaproxier/meta_proxier.go

@@ -17,15 +17,11 @@ limitations under the License.
 package metaproxier
 
 import (
-	"fmt"
-
 	v1 "k8s.io/api/core/v1"
 	discovery "k8s.io/api/discovery/v1"
 	"k8s.io/klog/v2"
 	"k8s.io/kubernetes/pkg/proxy"
 	"k8s.io/kubernetes/pkg/proxy/config"
-
-	utilnet "k8s.io/utils/net"
 )
 
 type metaProxier struct {
@@ -89,60 +85,6 @@ func (proxier *metaProxier) OnServiceSynced() {
 	proxier.ipv6Proxier.OnServiceSynced()
 }
 
-// OnEndpointsAdd is called whenever creation of new endpoints object
-// is observed.
-func (proxier *metaProxier) OnEndpointsAdd(endpoints *v1.Endpoints) {
-	ipFamily, err := endpointsIPFamily(endpoints)
-	if err != nil {
-		klog.V(4).Infof("failed to add endpoints %s/%s with error %v", endpoints.ObjectMeta.Namespace, endpoints.ObjectMeta.Name, err)
-		return
-	}
-	if *ipFamily == v1.IPv4Protocol {
-		proxier.ipv4Proxier.OnEndpointsAdd(endpoints)
-		return
-	}
-	proxier.ipv6Proxier.OnEndpointsAdd(endpoints)
-}
-
-// OnEndpointsUpdate is called whenever modification of an existing
-// endpoints object is observed.
-func (proxier *metaProxier) OnEndpointsUpdate(oldEndpoints, endpoints *v1.Endpoints) {
-	ipFamily, err := endpointsIPFamily(endpoints)
-	if err != nil {
-		klog.V(4).Infof("failed to update endpoints %s/%s with error %v", endpoints.ObjectMeta.Namespace, endpoints.ObjectMeta.Name, err)
-		return
-	}
-
-	if *ipFamily == v1.IPv4Protocol {
-		proxier.ipv4Proxier.OnEndpointsUpdate(oldEndpoints, endpoints)
-		return
-	}
-	proxier.ipv6Proxier.OnEndpointsUpdate(oldEndpoints, endpoints)
-}
-
-// OnEndpointsDelete is called whenever deletion of an existing
-// endpoints object is observed.
-func (proxier *metaProxier) OnEndpointsDelete(endpoints *v1.Endpoints) {
-	ipFamily, err := endpointsIPFamily(endpoints)
-	if err != nil {
-		klog.V(4).Infof("failed to delete endpoints %s/%s with error %v", endpoints.ObjectMeta.Namespace, endpoints.ObjectMeta.Name, err)
-		return
-	}
-
-	if *ipFamily == v1.IPv4Protocol {
-		proxier.ipv4Proxier.OnEndpointsDelete(endpoints)
-		return
-	}
-	proxier.ipv6Proxier.OnEndpointsDelete(endpoints)
-}
-
-// OnEndpointsSynced is called once all the initial event handlers
-// were called and the state is fully propagated to local cache.
-func (proxier *metaProxier) OnEndpointsSynced() {
-	proxier.ipv4Proxier.OnEndpointsSynced()
-	proxier.ipv6Proxier.OnEndpointsSynced()
-}
-
 // OnEndpointSliceAdd is called whenever creation of a new endpoint slice object
 // is observed.
 func (proxier *metaProxier) OnEndpointSliceAdd(endpointSlice *discovery.EndpointSlice) {
@@ -189,34 +131,6 @@ func (proxier *metaProxier) OnEndpointSlicesSynced() {
 	proxier.ipv6Proxier.OnEndpointSlicesSynced()
 }
 
-// endpointsIPFamily that returns IPFamily of endpoints or error if
-// failed to identify the IP family.
-func endpointsIPFamily(endpoints *v1.Endpoints) (*v1.IPFamily, error) {
-	if len(endpoints.Subsets) == 0 {
-		return nil, fmt.Errorf("failed to identify ipfamily for endpoints (no subsets)")
-	}
-
-	// we only need to work with subset [0],endpoint controller
-	// ensures that endpoints selected are of the same family.
-	subset := endpoints.Subsets[0]
-	if len(subset.Addresses) == 0 {
-		return nil, fmt.Errorf("failed to identify ipfamily for endpoints (no addresses)")
-	}
-	// same apply on addresses
-	address := subset.Addresses[0]
-	if len(address.IP) == 0 {
-		return nil, fmt.Errorf("failed to identify ipfamily for endpoints (address has no ip)")
-	}
-
-	ipv4 := v1.IPv4Protocol
-	ipv6 := v1.IPv6Protocol
-	if utilnet.IsIPv6String(address.IP) {
-		return &ipv6, nil
-	}
-
-	return &ipv4, nil
-}
-
 // OnNodeAdd is called whenever creation of new node object is observed.
 func (proxier *metaProxier) OnNodeAdd(node *v1.Node) {
 	proxier.ipv4Proxier.OnNodeAdd(node)

pkg/proxy/metaproxier/meta_proxier_test.go

@@ -1,89 +0,0 @@
-/*
-Copyright 2019 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package metaproxier
-
-import (
-	"reflect"
-	"testing"
-
-	v1 "k8s.io/api/core/v1"
-)
-
-func Test_endpointsIPFamily(t *testing.T) {
-
-	ipv4 := v1.IPv4Protocol
-	ipv6 := v1.IPv6Protocol
-
-	tests := []struct {
-		name      string
-		endpoints *v1.Endpoints
-		want      *v1.IPFamily
-		wantErr   bool
-		errorMsg  string
-	}{
-		{
-			name:      "Endpoints No Subsets",
-			endpoints: &v1.Endpoints{},
-			want:      nil,
-			wantErr:   true,
-			errorMsg:  "failed to identify ipfamily for endpoints (no subsets)",
-		},
-		{
-			name:      "Endpoints No Addresses",
-			endpoints: &v1.Endpoints{Subsets: []v1.EndpointSubset{{NotReadyAddresses: []v1.EndpointAddress{}}}},
-			want:      nil,
-			wantErr:   true,
-			errorMsg:  "failed to identify ipfamily for endpoints (no addresses)",
-		},
-		{
-			name:      "Endpoints Address Has No IP",
-			endpoints: &v1.Endpoints{Subsets: []v1.EndpointSubset{{Addresses: []v1.EndpointAddress{{Hostname: "testhost", IP: ""}}}}},
-			want:      nil,
-			wantErr:   true,
-			errorMsg:  "failed to identify ipfamily for endpoints (address has no ip)",
-		},
-		{
-			name:      "Endpoints Address IPv4",
-			endpoints: &v1.Endpoints{Subsets: []v1.EndpointSubset{{Addresses: []v1.EndpointAddress{{IP: "1.2.3.4"}}}}},
-			want:      &ipv4,
-			wantErr:   false,
-		},
-		{
-			name:      "Endpoints Address IPv6",
-			endpoints: &v1.Endpoints{Subsets: []v1.EndpointSubset{{Addresses: []v1.EndpointAddress{{IP: "2001:db9::2"}}}}},
-			want:      &ipv6,
-			wantErr:   false,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			got, err := endpointsIPFamily(tt.endpoints)
-			if (err != nil) != tt.wantErr {
-				t.Errorf("endpointsIPFamily() error = %v, wantErr %v", err, tt.wantErr)
-				return
-			}
-			if err != nil && err.Error() != tt.errorMsg {
-				t.Errorf("endpointsIPFamily() error = %v, wantErr %v", err, tt.errorMsg)
-				return
-			}
-			if !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("endpointsIPFamily() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}

pkg/proxy/types.go

@@ -28,7 +28,6 @@ import (
 
 // Provider is the interface provided by proxier implementations.
 type Provider interface {
-	config.EndpointsHandler
 	config.EndpointSliceHandler
 	config.ServiceHandler
 	config.NodeHandler

pkg/proxy/winkernel/proxier.go

@@ -942,25 +942,6 @@ func shouldSkipService(svcName types.NamespacedName, service *v1.Service) bool {
 	return false
 }
 
-// The following methods exist to implement the proxier interface, however
-// winkernel proxier only uses EndpointSlice, so the following are noops.
-
-// OnEndpointsAdd is called whenever creation of new endpoints object
-// is observed.
-func (proxier *Proxier) OnEndpointsAdd(endpoints *v1.Endpoints) {}
-
-// OnEndpointsUpdate is called whenever modification of an existing
-// endpoints object is observed.
-func (proxier *Proxier) OnEndpointsUpdate(oldEndpoints, endpoints *v1.Endpoints) {}
-
-// OnEndpointsDelete is called whenever deletion of an existing endpoints
-// object is observed.
-func (proxier *Proxier) OnEndpointsDelete(endpoints *v1.Endpoints) {}
-
-// OnEndpointsSynced is called once all the initial event handlers were
-// called and the state is fully propagated to local cache.
-func (proxier *Proxier) OnEndpointsSynced() {}
-
 // OnEndpointSliceAdd is called whenever creation of a new endpoint slice object
 // is observed.
 func (proxier *Proxier) OnEndpointSliceAdd(endpointSlice *discovery.EndpointSlice) {