Merge pull request #30486 from freehan/lbsrcfix

cmd/kube-proxy/app/server.go

@@ -204,8 +204,7 @@ func NewProxyServerDefault(config *options.ProxyServerConfig) (*ProxyServer, err
 			// IPTablesMasqueradeBit must be specified or defaulted.
 			return nil, fmt.Errorf("Unable to read IPTablesMasqueradeBit from config")
 		}
-
-		proxierIptables, err := iptables.NewProxier(iptInterface, execer, config.IPTablesSyncPeriod.Duration, config.MasqueradeAll, int(*config.IPTablesMasqueradeBit), config.ClusterCIDR, hostname)
+		proxierIptables, err := iptables.NewProxier(iptInterface, execer, config.IPTablesSyncPeriod.Duration, config.MasqueradeAll, int(*config.IPTablesMasqueradeBit), config.ClusterCIDR, hostname, getNodeIP(client, hostname))
 		if err != nil {
 			glog.Fatalf("Unable to create proxier: %v", err)
 		}
@@ -409,3 +408,18 @@ func tryIptablesProxy(iptver iptables.IptablesVersioner, kcompat iptables.Kernel
 func (s *ProxyServer) birthCry() {
 	s.Recorder.Eventf(s.Config.NodeRef, api.EventTypeNormal, "Starting", "Starting kube-proxy.")
 }
+
+func getNodeIP(client *kubeclient.Client, hostname string) net.IP {
+	var nodeIP net.IP
+	node, err := client.Nodes().Get(hostname)
+	if err != nil {
+		glog.Warningf("Failed to retrieve node info: %v", err)
+		return nil
+	}
+	nodeIP, err = nodeutil.GetNodeHostIP(node)
+	if err != nil {
+		glog.Warningf("Failed to retrieve node IP: %v", err)
+		return nil
+	}
+	return nodeIP
+}

cmd/kubelet/app/options/options.go

@@ -164,6 +164,9 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&s.ResolverConfig, "resolv-conf", s.ResolverConfig, "Resolver configuration file used as the basis for the container DNS resolution configuration.")
 	fs.BoolVar(&s.CPUCFSQuota, "cpu-cfs-quota", s.CPUCFSQuota, "Enable CPU CFS quota enforcement for containers that specify CPU limits")
 	fs.BoolVar(&s.EnableControllerAttachDetach, "enable-controller-attach-detach", s.EnableControllerAttachDetach, "Enables the Attach/Detach controller to manage attachment/detachment of volumes scheduled to this node, and disables kubelet from executing any attach/detach operations")
+	fs.BoolVar(&s.MakeIPTablesUtilChains, "make-iptables-util-chains", s.MakeIPTablesUtilChains, "If true, kubelet will ensure iptables utility rules are present on host.")
+	fs.Int32Var(&s.IPTablesMasqueradeBit, "iptables-masquerade-bit", s.IPTablesMasqueradeBit, "The bit of the fwmark space to mark packets for SNAT. Must be within the range [0, 31]. Please match this parameter with corresponding parameter in kube-proxy.")
+	fs.Int32Var(&s.IPTablesDropBit, "iptables-drop-bit", s.IPTablesDropBit, "The bit of the fwmark space to mark packets for dropping. Must be within the range [0, 31].")
 
 	// Flags intended for testing, not recommended used in production environments.
 	fs.BoolVar(&s.ReallyCrashForTesting, "really-crash-for-testing", s.ReallyCrashForTesting, "If true, when panics occur crash. Intended for testing.")

cmd/kubelet/app/server.go

@@ -199,6 +199,18 @@ func UnsecuredKubeletConfig(s *options.KubeletServer) (*KubeletConfig, error) {
 		Thresholds:               thresholds,
 	}
 
+	if s.MakeIPTablesUtilChains {
+		if s.IPTablesMasqueradeBit > 31 || s.IPTablesMasqueradeBit < 0 {
+			return nil, fmt.Errorf("iptables-masquerade-bit is not valid. Must be within [0, 31]")
+		}
+		if s.IPTablesDropBit > 31 || s.IPTablesDropBit < 0 {
+			return nil, fmt.Errorf("iptables-drop-bit is not valid. Must be within [0, 31]")
+		}
+		if s.IPTablesDropBit == s.IPTablesMasqueradeBit {
+			return nil, fmt.Errorf("iptables-masquerade-bit and iptables-drop-bit must be different")
+		}
+	}
+
 	return &KubeletConfig{
 		Address:                      net.ParseIP(s.Address),
 		AllowPrivileged:              s.AllowPrivileged,
@@ -281,10 +293,13 @@ func UnsecuredKubeletConfig(s *options.KubeletServer) (*KubeletConfig, error) {
 		HairpinMode:                    s.HairpinMode,
 		BabysitDaemons:                 s.BabysitDaemons,
 		ExperimentalFlannelOverlay:     s.ExperimentalFlannelOverlay,
-		NodeIP:                net.ParseIP(s.NodeIP),
-		EvictionConfig:        evictionConfig,
-		PodsPerCore:           int(s.PodsPerCore),
-		ProtectKernelDefaults: s.ProtectKernelDefaults,
+		NodeIP:                 net.ParseIP(s.NodeIP),
+		EvictionConfig:         evictionConfig,
+		PodsPerCore:            int(s.PodsPerCore),
+		ProtectKernelDefaults:  s.ProtectKernelDefaults,
+		MakeIPTablesUtilChains: s.MakeIPTablesUtilChains,
+		iptablesMasqueradeBit:  int(s.IPTablesMasqueradeBit),
+		iptablesDropBit:        int(s.IPTablesDropBit),
 	}, nil
 }
 
@@ -893,8 +908,10 @@ type KubeletConfig struct {
 	HairpinMode                string
 	BabysitDaemons             bool
 	Options                    []kubelet.Option
-
-	ProtectKernelDefaults bool
+	ProtectKernelDefaults      bool
+	MakeIPTablesUtilChains     bool
+	iptablesMasqueradeBit      int
+	iptablesDropBit            int
 }
 
 func CreateAndInitKubelet(kc *KubeletConfig) (k KubeletBootstrap, pc *config.PodConfig, err error) {
@@ -992,6 +1009,9 @@ func CreateAndInitKubelet(kc *KubeletConfig) (k KubeletBootstrap, pc *config.Pod
 		kc.EvictionConfig,
 		kc.Options,
 		kc.EnableControllerAttachDetach,
+		kc.MakeIPTablesUtilChains,
+		kc.iptablesMasqueradeBit,
+		kc.iptablesDropBit,
 	)
 
 	if err != nil {

hack/verify-flags/known-flags.txt

@@ -230,6 +230,7 @@ insecure-port
 insecure-skip-tls-verify
 instance-metadata
 instance-name-prefix
+iptables-drop-bit
 iptables-masquerade-bit
 iptables-sync-period
 ir-data-source
@@ -288,6 +289,7 @@ lock-file
 log-flush-frequency
 long-running-request-regexp
 low-diskspace-threshold-mb
+make-iptables-util-chains
 make-symlinks
 manifest-url
 manifest-url-header

pkg/apis/componentconfig/types.go

@@ -399,6 +399,18 @@ type KubeletConfiguration struct {
 	KubeReserved utilconfig.ConfigurationMap `json:"kubeReserved"`
 	// Default behaviour for kernel tuning
 	ProtectKernelDefaults bool `json:"protectKernelDefaults"`
+	// If true, Kubelet ensures a set of iptables rules are present on host.
+	// These rules will serve as utility for various components, e.g. kube-proxy.
+	// The rules will be created based on IPTablesMasqueradeBit and IPTablesDropBit.
+	MakeIPTablesUtilChains bool `json:"makeIPTablesUtilChains"`
+	// iptablesMasqueradeBit is the bit of the iptables fwmark space to use for SNAT
+	// Values must be within the range [0, 31].
+	// Warning: Please match the value of corresponding parameter in kube-proxy
+	// TODO: clean up IPTablesMasqueradeBit in kube-proxy
+	IPTablesMasqueradeBit int32 `json:"iptablesMasqueradeBit"`
+	// iptablesDropBit is the bit of the iptables fwmark space to use for dropping packets. Kubelet will ensure iptables mark and drop rules.
+	// Values must be within the range [0, 31]. Must be different from IPTablesMasqueradeBit
+	IPTablesDropBit int32 `json:"iptablesDropBit"`
 }
 
 type KubeSchedulerConfiguration struct {

pkg/apis/componentconfig/v1alpha1/defaults.go

@@ -43,6 +43,9 @@ const (
 	defaultRktAPIServiceEndpoint = "localhost:15441"
 
 	AutoDetectCloudProvider = "auto-detect"
+
+	defaultIPTablesMasqueradeBit = 14
+	defaultIPTablesDropBit       = 15
 )
 
 var zeroDuration = unversioned.Duration{}
@@ -337,6 +340,17 @@ func SetDefaults_KubeletConfiguration(obj *KubeletConfiguration) {
 	if obj.KubeReserved == nil {
 		obj.KubeReserved = make(map[string]string)
 	}
+	if obj.MakeIPTablesUtilChains == nil {
+		obj.MakeIPTablesUtilChains = boolVar(true)
+	}
+	if obj.IPTablesMasqueradeBit == nil {
+		temp := int32(defaultIPTablesMasqueradeBit)
+		obj.IPTablesMasqueradeBit = &temp
+	}
+	if obj.IPTablesDropBit == nil {
+		temp := int32(defaultIPTablesDropBit)
+		obj.IPTablesDropBit = &temp
+	}
 }
 
 func boolVar(b bool) *bool {

pkg/apis/componentconfig/v1alpha1/types.go

@@ -454,4 +454,16 @@ type KubeletConfiguration struct {
 	KubeReserved map[string]string `json:"kubeReserved"`
 	// Default behaviour for kernel tuning
 	ProtectKernelDefaults bool `json:"protectKernelDefaults"`
+	// If true, Kubelet ensures a set of iptables rules are present on host.
+	// These rules will serve as utility rules for various components, e.g. KubeProxy.
+	// The rules will be created based on IPTablesMasqueradeBit and IPTablesDropBit.
+	MakeIPTablesUtilChains *bool `json:"makeIPTablesUtilChains"`
+	// iptablesMasqueradeBit is the bit of the iptables fwmark space to mark for SNAT
+	// Values must be within the range [0, 31]. Must be different from other mark bits.
+	// Warning: Please match the value of corresponding parameter in kube-proxy
+	// TODO: clean up IPTablesMasqueradeBit in kube-proxy
+	IPTablesMasqueradeBit *int32 `json:"iptablesMasqueradeBit"`
+	// iptablesDropBit is the bit of the iptables fwmark space to mark for dropping packets.
+	// Values must be within the range [0, 31]. Must be different from other mark bits.
+	IPTablesDropBit *int32 `json:"iptablesDropBit"`
 }

pkg/apis/componentconfig/v1alpha1/zz_generated.conversion.go

@@ -320,6 +320,15 @@ func autoConvert_v1alpha1_KubeletConfiguration_To_componentconfig_KubeletConfigu
 		out.KubeReserved = nil
 	}
 	out.ProtectKernelDefaults = in.ProtectKernelDefaults
+	if err := api.Convert_Pointer_bool_To_bool(&in.MakeIPTablesUtilChains, &out.MakeIPTablesUtilChains, s); err != nil {
+		return err
+	}
+	if err := api.Convert_Pointer_int32_To_int32(&in.IPTablesMasqueradeBit, &out.IPTablesMasqueradeBit, s); err != nil {
+		return err
+	}
+	if err := api.Convert_Pointer_int32_To_int32(&in.IPTablesDropBit, &out.IPTablesDropBit, s); err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -485,6 +494,15 @@ func autoConvert_componentconfig_KubeletConfiguration_To_v1alpha1_KubeletConfigu
 		out.KubeReserved = nil
 	}
 	out.ProtectKernelDefaults = in.ProtectKernelDefaults
+	if err := api.Convert_bool_To_Pointer_bool(&in.MakeIPTablesUtilChains, &out.MakeIPTablesUtilChains, s); err != nil {
+		return err
+	}
+	if err := api.Convert_int32_To_Pointer_int32(&in.IPTablesMasqueradeBit, &out.IPTablesMasqueradeBit, s); err != nil {
+		return err
+	}
+	if err := api.Convert_int32_To_Pointer_int32(&in.IPTablesDropBit, &out.IPTablesDropBit, s); err != nil {
+		return err
+	}
 	return nil
 }
 

pkg/apis/componentconfig/v1alpha1/zz_generated.deepcopy.go

@@ -378,6 +378,27 @@ func DeepCopy_v1alpha1_KubeletConfiguration(in interface{}, out interface{}, c *
 			out.KubeReserved = nil
 		}
 		out.ProtectKernelDefaults = in.ProtectKernelDefaults
+		if in.MakeIPTablesUtilChains != nil {
+			in, out := &in.MakeIPTablesUtilChains, &out.MakeIPTablesUtilChains
+			*out = new(bool)
+			**out = **in
+		} else {
+			out.MakeIPTablesUtilChains = nil
+		}
+		if in.IPTablesMasqueradeBit != nil {
+			in, out := &in.IPTablesMasqueradeBit, &out.IPTablesMasqueradeBit
+			*out = new(int32)
+			**out = **in
+		} else {
+			out.IPTablesMasqueradeBit = nil
+		}
+		if in.IPTablesDropBit != nil {
+			in, out := &in.IPTablesDropBit, &out.IPTablesDropBit
+			*out = new(int32)
+			**out = **in
+		} else {
+			out.IPTablesDropBit = nil
+		}
 		return nil
 	}
 }

pkg/apis/componentconfig/zz_generated.deepcopy.go

@@ -326,6 +326,9 @@ func DeepCopy_componentconfig_KubeletConfiguration(in interface{}, out interface
 			out.KubeReserved = nil
 		}
 		out.ProtectKernelDefaults = in.ProtectKernelDefaults
+		out.MakeIPTablesUtilChains = in.MakeIPTablesUtilChains
+		out.IPTablesMasqueradeBit = in.IPTablesMasqueradeBit
+		out.IPTablesDropBit = in.IPTablesDropBit
 		return nil
 	}
 }

pkg/kubelet/kubelet.go

@@ -244,6 +244,9 @@ func NewMainKubelet(
 	evictionConfig eviction.Config,
 	kubeOptions []Option,
 	enableControllerAttachDetach bool,
+	makeIPTablesUtilChains bool,
+	iptablesMasqueradeBit int,
+	iptablesDropBit int,
 ) (*Kubelet, error) {
 	if rootDirectory == "" {
 		return nil, fmt.Errorf("invalid root directory %q", rootDirectory)
@@ -368,6 +371,9 @@ func NewMainKubelet(
 		babysitDaemons:               babysitDaemons,
 		enableControllerAttachDetach: enableControllerAttachDetach,
 		iptClient:                    utilipt.New(utilexec.New(), utildbus.New(), utilipt.ProtocolIpv4),
+		makeIPTablesUtilChains:       makeIPTablesUtilChains,
+		iptablesMasqueradeBit:        iptablesMasqueradeBit,
+		iptablesDropBit:              iptablesDropBit,
 	}
 
 	if klet.flannelExperimentalOverlay {
@@ -845,6 +851,15 @@ type Kubelet struct {
 
 	// trigger deleting containers in a pod
 	containerDeletor *podContainerDeletor
+
+	// config iptables util rules
+	makeIPTablesUtilChains bool
+
+	// The bit of the fwmark space to mark packets for SNAT.
+	iptablesMasqueradeBit int
+
+	// The bit of the fwmark space to mark packets for dropping.
+	iptablesDropBit int
 }
 
 // setupDataDirs creates:
@@ -971,6 +986,11 @@ func (kl *Kubelet) Run(updates <-chan kubetypes.PodUpdate) {
 	go wait.Until(kl.syncNetworkStatus, 30*time.Second, wait.NeverStop)
 	go wait.Until(kl.updateRuntimeUp, 5*time.Second, wait.NeverStop)
 
+	// Start loop to sync iptables util rules
+	if kl.makeIPTablesUtilChains {
+		go wait.Until(kl.syncNetworkUtil, 1*time.Minute, wait.NeverStop)
+	}
+
 	// Start a goroutine responsible for killing pods (that are not properly
 	// handled by pod workers).
 	go wait.Until(kl.podKiller, 1*time.Second, wait.NeverStop)

pkg/kubelet/kubelet_network.go

@@ -28,9 +28,25 @@ import (
 	"k8s.io/kubernetes/pkg/apis/componentconfig"
 	"k8s.io/kubernetes/pkg/kubelet/network"
 	"k8s.io/kubernetes/pkg/util/bandwidth"
+	utiliptables "k8s.io/kubernetes/pkg/util/iptables"
 	"k8s.io/kubernetes/pkg/util/sets"
 )
 
+const (
+	// the mark-for-masquerade chain
+	// TODO: clean up this logic in kube-proxy
+	KubeMarkMasqChain utiliptables.Chain = "KUBE-MARK-MASQ"
+
+	// the mark-for-drop chain
+	KubeMarkDropChain utiliptables.Chain = "KUBE-MARK-DROP"
+
+	// kubernetes postrouting rules
+	KubePostroutingChain utiliptables.Chain = "KUBE-POSTROUTING"
+
+	// kubernetes postrouting rules
+	KubeFirewallChain utiliptables.Chain = "KUBE-FIREWALL"
+)
+
 // effectiveHairpinMode determines the effective hairpin mode given the
 // configured mode, container runtime, and whether cbr0 should be configured.
 func effectiveHairpinMode(hairpinMode componentconfig.HairpinMode, containerRuntime string, configureCBR0 bool, networkPlugin string) (componentconfig.HairpinMode, error) {
@@ -303,3 +319,88 @@ func (kl *Kubelet) shapingEnabled() bool {
 	}
 	return true
 }
+
+// syncNetworkUtil ensures the network utility are present on host.
+// Network util includes:
+// 1. 	In nat table, KUBE-MARK-DROP rule to mark connections for dropping
+// 	Marked connection will be drop on INPUT/OUTPUT Chain in filter table
+// 2. 	In nat table, KUBE-MARK-MASQ rule to mark connections for SNAT
+// 	Marked connection will get SNAT on POSTROUTING Chain in nat table
+func (kl *Kubelet) syncNetworkUtil() {
+	if kl.iptablesMasqueradeBit < 0 || kl.iptablesMasqueradeBit > 31 {
+		glog.Errorf("invalid iptables-masquerade-bit %v not in [0, 31]", kl.iptablesMasqueradeBit)
+		return
+	}
+
+	if kl.iptablesDropBit < 0 || kl.iptablesDropBit > 31 {
+		glog.Errorf("invalid iptables-drop-bit %v not in [0, 31]", kl.iptablesDropBit)
+		return
+	}
+
+	if kl.iptablesDropBit == kl.iptablesMasqueradeBit {
+		glog.Errorf("iptables-masquerade-bit %v and iptables-drop-bit %v must be different", kl.iptablesMasqueradeBit, kl.iptablesDropBit)
+		return
+	}
+
+	// Setup KUBE-MARK-DROP rules
+	dropMark := getIPTablesMark(kl.iptablesDropBit)
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkDropChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkDropChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkDropChain, "-j", "MARK", "--set-xmark", dropMark); err != nil {
+		glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkDropChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableFilter, KubeFirewallChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableFilter, KubeFirewallChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableFilter, KubeFirewallChain,
+		"-m", "comment", "--comment", "kubernetes firewall for dropping marked packets",
+		"-m", "mark", "--mark", dropMark,
+		"-j", "DROP"); err != nil {
+		glog.Errorf("Failed to ensure rule to drop packet marked by %v in %v chain %v: %v", KubeMarkDropChain, utiliptables.TableFilter, KubeFirewallChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainOutput, "-j", string(KubeFirewallChain)); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainOutput, KubeFirewallChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainInput, "-j", string(KubeFirewallChain)); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainInput, KubeFirewallChain, err)
+		return
+	}
+
+	// Setup KUBE-MARK-MASQ rules
+	masqueradeMark := getIPTablesMark(kl.iptablesMasqueradeBit)
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkMasqChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkMasqChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubePostroutingChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubePostroutingChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkMasqChain, "-j", "MARK", "--set-xmark", masqueradeMark); err != nil {
+		glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkMasqChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableNAT, utiliptables.ChainPostrouting,
+		"-m", "comment", "--comment", "kubernetes postrouting rules", "-j", string(KubePostroutingChain)); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableNAT, utiliptables.ChainPostrouting, KubePostroutingChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubePostroutingChain,
+		"-m", "comment", "--comment", "kubernetes service traffic requiring SNAT",
+		"-m", "mark", "--mark", masqueradeMark, "-j", "MASQUERADE"); err != nil {
+		glog.Errorf("Failed to ensure SNAT rule for packets marked by %v in %v chain %v: %v", KubeMarkMasqChain, utiliptables.TableNAT, KubePostroutingChain, err)
+		return
+	}
+}
+
+// getIPTablesMark returns the fwmark given the bit
+func getIPTablesMark(bit int) string {
+	value := 1 << uint(bit)
+	return fmt.Sprintf("%#08x/%#08x", value, value)
+}

pkg/kubelet/kubelet_network_test.go

@@ -217,3 +217,25 @@ func TestCleanupBandwidthLimits(t *testing.T) {
 		}
 	}
 }
+
+func TestGetIPTablesMark(t *testing.T) {
+	tests := []struct {
+		bit    int
+		expect string
+	}{
+		{
+			14,
+			"0x00004000/0x00004000",
+		},
+		{
+			15,
+			"0x00008000/0x00008000",
+		},
+	}
+	for _, tc := range tests {
+		res := getIPTablesMark(tc.bit)
+		if res != tc.expect {
+			t.Errorf("getIPTablesMark output unexpected result: %v when input bit is %d. Expect result: %v", res, tc.bit, tc.expect)
+		}
+	}
+}