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proxier.go
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proxier.go
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/*
Copyright 2015 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 iptables
//
// NOTE: this needs to be tested in e2e since it uses iptables for everything.
//
import (
"bytes"
"crypto/sha256"
"encoding/base32"
"fmt"
"net"
"reflect"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
"github.com/golang/glog"
"k8s.io/apimachinery/pkg/types"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/apimachinery/pkg/util/wait"
utilfeature "k8s.io/apiserver/pkg/util/feature"
clientv1 "k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/record"
"k8s.io/kubernetes/pkg/api"
"k8s.io/kubernetes/pkg/api/helper"
apiservice "k8s.io/kubernetes/pkg/api/service"
"k8s.io/kubernetes/pkg/features"
"k8s.io/kubernetes/pkg/proxy"
"k8s.io/kubernetes/pkg/proxy/healthcheck"
utilproxy "k8s.io/kubernetes/pkg/proxy/util"
"k8s.io/kubernetes/pkg/util/async"
utilexec "k8s.io/kubernetes/pkg/util/exec"
utiliptables "k8s.io/kubernetes/pkg/util/iptables"
utilsysctl "k8s.io/kubernetes/pkg/util/sysctl"
utilversion "k8s.io/kubernetes/pkg/util/version"
)
const (
// iptablesMinVersion is the minimum version of iptables for which we will use the Proxier
// from this package instead of the userspace Proxier. While most of the
// features we need were available earlier, the '-C' flag was added more
// recently. We use that indirectly in Ensure* functions, and if we don't
// have it, we have to be extra careful about the exact args we feed in being
// the same as the args we read back (iptables itself normalizes some args).
// This is the "new" Proxier, so we require "new" versions of tools.
iptablesMinVersion = utiliptables.MinCheckVersion
// the services chain
kubeServicesChain utiliptables.Chain = "KUBE-SERVICES"
// the nodeports chain
kubeNodePortsChain utiliptables.Chain = "KUBE-NODEPORTS"
// the kubernetes postrouting chain
kubePostroutingChain utiliptables.Chain = "KUBE-POSTROUTING"
// the mark-for-masquerade chain
KubeMarkMasqChain utiliptables.Chain = "KUBE-MARK-MASQ"
// the mark-for-drop chain
KubeMarkDropChain utiliptables.Chain = "KUBE-MARK-DROP"
)
// IPTablesVersioner can query the current iptables version.
type IPTablesVersioner interface {
// returns "X.Y.Z"
GetVersion() (string, error)
}
// KernelCompatTester tests whether the required kernel capabilities are
// present to run the iptables proxier.
type KernelCompatTester interface {
IsCompatible() error
}
// CanUseIPTablesProxier returns true if we should use the iptables Proxier
// instead of the "classic" userspace Proxier. This is determined by checking
// the iptables version and for the existence of kernel features. It may return
// an error if it fails to get the iptables version without error, in which
// case it will also return false.
func CanUseIPTablesProxier(iptver IPTablesVersioner, kcompat KernelCompatTester) (bool, error) {
minVersion, err := utilversion.ParseGeneric(iptablesMinVersion)
if err != nil {
return false, err
}
versionString, err := iptver.GetVersion()
if err != nil {
return false, err
}
version, err := utilversion.ParseGeneric(versionString)
if err != nil {
return false, err
}
if version.LessThan(minVersion) {
return false, nil
}
// Check that the kernel supports what we need.
if err := kcompat.IsCompatible(); err != nil {
return false, err
}
return true, nil
}
type LinuxKernelCompatTester struct{}
func (lkct LinuxKernelCompatTester) IsCompatible() error {
// Check for the required sysctls. We don't care about the value, just
// that it exists. If this Proxier is chosen, we'll initialize it as we
// need.
_, err := utilsysctl.New().GetSysctl(sysctlRouteLocalnet)
return err
}
const sysctlRouteLocalnet = "net/ipv4/conf/all/route_localnet"
const sysctlBridgeCallIPTables = "net/bridge/bridge-nf-call-iptables"
// internal struct for string service information
type serviceInfo struct {
clusterIP net.IP
port int
protocol api.Protocol
nodePort int
loadBalancerStatus api.LoadBalancerStatus
sessionAffinityType api.ServiceAffinity
stickyMaxAgeMinutes int
externalIPs []string
loadBalancerSourceRanges []string
onlyNodeLocalEndpoints bool
healthCheckNodePort int
// The following fields are computed and stored for performance reasons.
serviceNameString string
servicePortChainName utiliptables.Chain
serviceFirewallChainName utiliptables.Chain
serviceLBChainName utiliptables.Chain
}
// internal struct for endpoints information
type endpointsInfo struct {
endpoint string // TODO: should be an endpointString type
isLocal bool
// The following fields we lazily compute and store here for performance
// reasons. If the protocol is the same as you expect it to be, then the
// chainName can be reused, otherwise it should be recomputed.
protocol string
chainName utiliptables.Chain
}
// Returns just the IP part of the endpoint.
func (e *endpointsInfo) IPPart() string {
if index := strings.Index(e.endpoint, ":"); index != -1 {
return e.endpoint[0:index]
}
return e.endpoint
}
// Returns the endpoint chain name for a given endpointsInfo.
func (e *endpointsInfo) endpointChain(svcNameString, protocol string) utiliptables.Chain {
if e.protocol != protocol {
e.protocol = protocol
e.chainName = servicePortEndpointChainName(svcNameString, protocol, e.endpoint)
}
return e.chainName
}
func (e *endpointsInfo) String() string {
return fmt.Sprintf("%v", *e)
}
// returns a new serviceInfo struct
func newServiceInfo(svcPortName proxy.ServicePortName, port *api.ServicePort, service *api.Service) *serviceInfo {
onlyNodeLocalEndpoints := false
if utilfeature.DefaultFeatureGate.Enabled(features.ExternalTrafficLocalOnly) &&
apiservice.RequestsOnlyLocalTraffic(service) {
onlyNodeLocalEndpoints = true
}
info := &serviceInfo{
clusterIP: net.ParseIP(service.Spec.ClusterIP),
port: int(port.Port),
protocol: port.Protocol,
nodePort: int(port.NodePort),
// Deep-copy in case the service instance changes
loadBalancerStatus: *helper.LoadBalancerStatusDeepCopy(&service.Status.LoadBalancer),
sessionAffinityType: service.Spec.SessionAffinity,
stickyMaxAgeMinutes: 180, // TODO: paramaterize this in the API.
externalIPs: make([]string, len(service.Spec.ExternalIPs)),
loadBalancerSourceRanges: make([]string, len(service.Spec.LoadBalancerSourceRanges)),
onlyNodeLocalEndpoints: onlyNodeLocalEndpoints,
}
copy(info.loadBalancerSourceRanges, service.Spec.LoadBalancerSourceRanges)
copy(info.externalIPs, service.Spec.ExternalIPs)
if apiservice.NeedsHealthCheck(service) {
p := apiservice.GetServiceHealthCheckNodePort(service)
if p == 0 {
glog.Errorf("Service %q has no healthcheck nodeport", svcPortName.NamespacedName.String())
} else {
info.healthCheckNodePort = int(p)
}
}
// Store the following for performance reasons.
protocol := strings.ToLower(string(info.protocol))
info.serviceNameString = svcPortName.String()
info.servicePortChainName = servicePortChainName(info.serviceNameString, protocol)
info.serviceFirewallChainName = serviceFirewallChainName(info.serviceNameString, protocol)
info.serviceLBChainName = serviceLBChainName(info.serviceNameString, protocol)
return info
}
type endpointsChange struct {
previous proxyEndpointsMap
current proxyEndpointsMap
}
type endpointsChangeMap struct {
lock sync.Mutex
hostname string
items map[types.NamespacedName]*endpointsChange
}
type serviceChange struct {
previous proxyServiceMap
current proxyServiceMap
}
type serviceChangeMap struct {
lock sync.Mutex
items map[types.NamespacedName]*serviceChange
}
type updateEndpointMapResult struct {
hcEndpoints map[types.NamespacedName]int
staleEndpoints map[endpointServicePair]bool
staleServiceNames map[proxy.ServicePortName]bool
}
type updateServiceMapResult struct {
hcServices map[types.NamespacedName]uint16
staleServices sets.String
}
type proxyServiceMap map[proxy.ServicePortName]*serviceInfo
type proxyEndpointsMap map[proxy.ServicePortName][]*endpointsInfo
func newEndpointsChangeMap(hostname string) endpointsChangeMap {
return endpointsChangeMap{
hostname: hostname,
items: make(map[types.NamespacedName]*endpointsChange),
}
}
func (ecm *endpointsChangeMap) update(namespacedName *types.NamespacedName, previous, current *api.Endpoints) bool {
ecm.lock.Lock()
defer ecm.lock.Unlock()
change, exists := ecm.items[*namespacedName]
if !exists {
change = &endpointsChange{}
change.previous = endpointsToEndpointsMap(previous, ecm.hostname)
ecm.items[*namespacedName] = change
}
change.current = endpointsToEndpointsMap(current, ecm.hostname)
if reflect.DeepEqual(change.previous, change.current) {
delete(ecm.items, *namespacedName)
}
return len(ecm.items) > 0
}
func newServiceChangeMap() serviceChangeMap {
return serviceChangeMap{
items: make(map[types.NamespacedName]*serviceChange),
}
}
func (scm *serviceChangeMap) update(namespacedName *types.NamespacedName, previous, current *api.Service) bool {
scm.lock.Lock()
defer scm.lock.Unlock()
change, exists := scm.items[*namespacedName]
if !exists {
change = &serviceChange{}
change.previous = serviceToServiceMap(previous)
scm.items[*namespacedName] = change
}
change.current = serviceToServiceMap(current)
if reflect.DeepEqual(change.previous, change.current) {
delete(scm.items, *namespacedName)
}
return len(scm.items) > 0
}
func (sm *proxyServiceMap) merge(other proxyServiceMap) sets.String {
existingPorts := sets.NewString()
for svcPortName, info := range other {
existingPorts.Insert(svcPortName.Port)
_, exists := (*sm)[svcPortName]
if !exists {
glog.V(1).Infof("Adding new service port %q at %s:%d/%s", svcPortName, info.clusterIP, info.port, info.protocol)
} else {
glog.V(1).Infof("Updating existing service port %q at %s:%d/%s", svcPortName, info.clusterIP, info.port, info.protocol)
}
(*sm)[svcPortName] = info
}
return existingPorts
}
func (sm *proxyServiceMap) unmerge(other proxyServiceMap, existingPorts, staleServices sets.String) {
for svcPortName := range other {
if existingPorts.Has(svcPortName.Port) {
continue
}
info, exists := (*sm)[svcPortName]
if exists {
glog.V(1).Infof("Removing service port %q", svcPortName)
if info.protocol == api.ProtocolUDP {
staleServices.Insert(info.clusterIP.String())
}
delete(*sm, svcPortName)
} else {
glog.Errorf("Service port %q removed, but doesn't exists", svcPortName)
}
}
}
func (em proxyEndpointsMap) merge(other proxyEndpointsMap) {
for svcPortName := range other {
em[svcPortName] = other[svcPortName]
}
}
func (em proxyEndpointsMap) unmerge(other proxyEndpointsMap) {
for svcPortName := range other {
delete(em, svcPortName)
}
}
// Proxier is an iptables based proxy for connections between a localhost:lport
// and services that provide the actual backends.
type Proxier struct {
// endpointsChanges and serviceChanges contains all changes to endpoints and
// services that happened since iptables was synced. For a single object,
// changes are accumulated, i.e. previous is state from before all of them,
// current is state after applying all of those.
endpointsChanges endpointsChangeMap
serviceChanges serviceChangeMap
mu sync.Mutex // protects the following fields
serviceMap proxyServiceMap
endpointsMap proxyEndpointsMap
portsMap map[localPort]closeable
// endpointsSynced and servicesSynced are set to true when corresponding
// objects are synced after startup. This is used to avoid updating iptables
// with some partial data after kube-proxy restart.
endpointsSynced bool
servicesSynced bool
initialized int32
syncRunner *async.BoundedFrequencyRunner // governs calls to syncProxyRules
// These are effectively const and do not need the mutex to be held.
iptables utiliptables.Interface
masqueradeAll bool
masqueradeMark string
exec utilexec.Interface
clusterCIDR string
hostname string
nodeIP net.IP
portMapper portOpener
recorder record.EventRecorder
healthChecker healthcheck.Server
healthzServer healthcheck.HealthzUpdater
// Since converting probabilities (floats) to strings is expensive
// and we are using only probabilities in the format of 1/n, we are
// precomputing some number of those and cache for future reuse.
precomputedProbabilities []string
// The following buffers are used to reuse memory and avoid allocations
// that are significantly impacting performance.
iptablesData *bytes.Buffer
filterChains *bytes.Buffer
filterRules *bytes.Buffer
natChains *bytes.Buffer
natRules *bytes.Buffer
}
type localPort struct {
desc string
ip string
port int
protocol string
}
func (lp *localPort) String() string {
return fmt.Sprintf("%q (%s:%d/%s)", lp.desc, lp.ip, lp.port, lp.protocol)
}
type closeable interface {
Close() error
}
// portOpener is an interface around port opening/closing.
// Abstracted out for testing.
type portOpener interface {
OpenLocalPort(lp *localPort) (closeable, error)
}
// listenPortOpener opens ports by calling bind() and listen().
type listenPortOpener struct{}
// OpenLocalPort holds the given local port open.
func (l *listenPortOpener) OpenLocalPort(lp *localPort) (closeable, error) {
return openLocalPort(lp)
}
// Proxier implements ProxyProvider
var _ proxy.ProxyProvider = &Proxier{}
// NewProxier returns a new Proxier given an iptables Interface instance.
// Because of the iptables logic, it is assumed that there is only a single Proxier active on a machine.
// An error will be returned if iptables fails to update or acquire the initial lock.
// Once a proxier is created, it will keep iptables up to date in the background and
// will not terminate if a particular iptables call fails.
func NewProxier(ipt utiliptables.Interface,
sysctl utilsysctl.Interface,
exec utilexec.Interface,
syncPeriod time.Duration,
minSyncPeriod time.Duration,
masqueradeAll bool,
masqueradeBit int,
clusterCIDR string,
hostname string,
nodeIP net.IP,
recorder record.EventRecorder,
healthzServer healthcheck.HealthzUpdater,
) (*Proxier, error) {
// check valid user input
if minSyncPeriod > syncPeriod {
return nil, fmt.Errorf("minSyncPeriod (%v) must be <= syncPeriod (%v)", minSyncPeriod, syncPeriod)
}
// Set the route_localnet sysctl we need for
if err := sysctl.SetSysctl(sysctlRouteLocalnet, 1); err != nil {
return nil, fmt.Errorf("can't set sysctl %s: %v", sysctlRouteLocalnet, err)
}
// Proxy needs br_netfilter and bridge-nf-call-iptables=1 when containers
// are connected to a Linux bridge (but not SDN bridges). Until most
// plugins handle this, log when config is missing
if val, err := sysctl.GetSysctl(sysctlBridgeCallIPTables); err == nil && val != 1 {
glog.Warningf("missing br-netfilter module or unset sysctl br-nf-call-iptables; proxy may not work as intended")
}
// Generate the masquerade mark to use for SNAT rules.
if masqueradeBit < 0 || masqueradeBit > 31 {
return nil, fmt.Errorf("invalid iptables-masquerade-bit %v not in [0, 31]", masqueradeBit)
}
masqueradeValue := 1 << uint(masqueradeBit)
masqueradeMark := fmt.Sprintf("%#08x/%#08x", masqueradeValue, masqueradeValue)
if nodeIP == nil {
glog.Warningf("invalid nodeIP, initializing kube-proxy with 127.0.0.1 as nodeIP")
nodeIP = net.ParseIP("127.0.0.1")
}
if len(clusterCIDR) == 0 {
glog.Warningf("clusterCIDR not specified, unable to distinguish between internal and external traffic")
}
healthChecker := healthcheck.NewServer(hostname, recorder, nil, nil) // use default implementations of deps
proxier := &Proxier{
portsMap: make(map[localPort]closeable),
serviceMap: make(proxyServiceMap),
serviceChanges: newServiceChangeMap(),
endpointsMap: make(proxyEndpointsMap),
endpointsChanges: newEndpointsChangeMap(hostname),
iptables: ipt,
masqueradeAll: masqueradeAll,
masqueradeMark: masqueradeMark,
exec: exec,
clusterCIDR: clusterCIDR,
hostname: hostname,
nodeIP: nodeIP,
portMapper: &listenPortOpener{},
recorder: recorder,
healthChecker: healthChecker,
healthzServer: healthzServer,
precomputedProbabilities: make([]string, 0, 1001),
iptablesData: bytes.NewBuffer(nil),
filterChains: bytes.NewBuffer(nil),
filterRules: bytes.NewBuffer(nil),
natChains: bytes.NewBuffer(nil),
natRules: bytes.NewBuffer(nil),
}
burstSyncs := 2
glog.V(3).Infof("minSyncPeriod: %v, syncPeriod: %v, burstSyncs: %d", minSyncPeriod, syncPeriod, burstSyncs)
proxier.syncRunner = async.NewBoundedFrequencyRunner("sync-runner", proxier.syncProxyRules, minSyncPeriod, syncPeriod, burstSyncs)
return proxier, nil
}
// CleanupLeftovers removes all iptables rules and chains created by the Proxier
// It returns true if an error was encountered. Errors are logged.
func CleanupLeftovers(ipt utiliptables.Interface) (encounteredError bool) {
// Unlink the services chain.
args := []string{
"-m", "comment", "--comment", "kubernetes service portals",
"-j", string(kubeServicesChain),
}
tableChainsWithJumpServices := []struct {
table utiliptables.Table
chain utiliptables.Chain
}{
{utiliptables.TableFilter, utiliptables.ChainInput},
{utiliptables.TableFilter, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainPrerouting},
}
for _, tc := range tableChainsWithJumpServices {
if err := ipt.DeleteRule(tc.table, tc.chain, args...); err != nil {
if !utiliptables.IsNotFoundError(err) {
glog.Errorf("Error removing pure-iptables proxy rule: %v", err)
encounteredError = true
}
}
}
// Unlink the postrouting chain.
args = []string{
"-m", "comment", "--comment", "kubernetes postrouting rules",
"-j", string(kubePostroutingChain),
}
if err := ipt.DeleteRule(utiliptables.TableNAT, utiliptables.ChainPostrouting, args...); err != nil {
if !utiliptables.IsNotFoundError(err) {
glog.Errorf("Error removing pure-iptables proxy rule: %v", err)
encounteredError = true
}
}
// Flush and remove all of our chains.
iptablesData := bytes.NewBuffer(nil)
if err := ipt.SaveInto(utiliptables.TableNAT, iptablesData); err != nil {
glog.Errorf("Failed to execute iptables-save for %s: %v", utiliptables.TableNAT, err)
encounteredError = true
} else {
existingNATChains := utiliptables.GetChainLines(utiliptables.TableNAT, iptablesData.Bytes())
natChains := bytes.NewBuffer(nil)
natRules := bytes.NewBuffer(nil)
writeLine(natChains, "*nat")
// Start with chains we know we need to remove.
for _, chain := range []utiliptables.Chain{kubeServicesChain, kubeNodePortsChain, kubePostroutingChain, KubeMarkMasqChain} {
if _, found := existingNATChains[chain]; found {
chainString := string(chain)
writeLine(natChains, existingNATChains[chain]) // flush
writeLine(natRules, "-X", chainString) // delete
}
}
// Hunt for service and endpoint chains.
for chain := range existingNATChains {
chainString := string(chain)
if strings.HasPrefix(chainString, "KUBE-SVC-") || strings.HasPrefix(chainString, "KUBE-SEP-") || strings.HasPrefix(chainString, "KUBE-FW-") || strings.HasPrefix(chainString, "KUBE-XLB-") {
writeLine(natChains, existingNATChains[chain]) // flush
writeLine(natRules, "-X", chainString) // delete
}
}
writeLine(natRules, "COMMIT")
natLines := append(natChains.Bytes(), natRules.Bytes()...)
// Write it.
err = ipt.Restore(utiliptables.TableNAT, natLines, utiliptables.NoFlushTables, utiliptables.RestoreCounters)
if err != nil {
glog.Errorf("Failed to execute iptables-restore for %s: %v", utiliptables.TableNAT, err)
encounteredError = true
}
}
{
filterBuf := bytes.NewBuffer(nil)
writeLine(filterBuf, "*filter")
writeLine(filterBuf, fmt.Sprintf(":%s - [0:0]", kubeServicesChain))
writeLine(filterBuf, fmt.Sprintf("-X %s", kubeServicesChain))
writeLine(filterBuf, "COMMIT")
// Write it.
if err := ipt.Restore(utiliptables.TableFilter, filterBuf.Bytes(), utiliptables.NoFlushTables, utiliptables.RestoreCounters); err != nil {
glog.Errorf("Failed to execute iptables-restore for %s: %v", utiliptables.TableFilter, err)
encounteredError = true
}
}
return encounteredError
}
func computeProbability(n int) string {
return fmt.Sprintf("%0.5f", 1.0/float64(n))
}
// This assumes proxier.mu is held
func (proxier *Proxier) precomputeProbabilities(numberOfPrecomputed int) {
if len(proxier.precomputedProbabilities) == 0 {
proxier.precomputedProbabilities = append(proxier.precomputedProbabilities, "<bad value>")
}
for i := len(proxier.precomputedProbabilities); i <= numberOfPrecomputed; i++ {
proxier.precomputedProbabilities = append(proxier.precomputedProbabilities, computeProbability(i))
}
}
// This assumes proxier.mu is held
func (proxier *Proxier) probability(n int) string {
if n >= len(proxier.precomputedProbabilities) {
proxier.precomputeProbabilities(n)
}
return proxier.precomputedProbabilities[n]
}
// Sync is called to synchronize the proxier state to iptables as soon as possible.
func (proxier *Proxier) Sync() {
proxier.syncRunner.Run()
}
// SyncLoop runs periodic work. This is expected to run as a goroutine or as the main loop of the app. It does not return.
func (proxier *Proxier) SyncLoop() {
// Update healthz timestamp at beginning in case Sync() never succeeds.
if proxier.healthzServer != nil {
proxier.healthzServer.UpdateTimestamp()
}
proxier.syncRunner.Loop(wait.NeverStop)
}
func (proxier *Proxier) setInitialized(value bool) {
var initialized int32
if value {
initialized = 1
}
atomic.StoreInt32(&proxier.initialized, initialized)
}
func (proxier *Proxier) isInitialized() bool {
return atomic.LoadInt32(&proxier.initialized) > 0
}
func (proxier *Proxier) OnServiceAdd(service *api.Service) {
namespacedName := types.NamespacedName{Namespace: service.Namespace, Name: service.Name}
if proxier.serviceChanges.update(&namespacedName, nil, service) && proxier.isInitialized() {
proxier.syncRunner.Run()
}
}
func (proxier *Proxier) OnServiceUpdate(oldService, service *api.Service) {
namespacedName := types.NamespacedName{Namespace: service.Namespace, Name: service.Name}
if proxier.serviceChanges.update(&namespacedName, oldService, service) && proxier.isInitialized() {
proxier.syncRunner.Run()
}
}
func (proxier *Proxier) OnServiceDelete(service *api.Service) {
namespacedName := types.NamespacedName{Namespace: service.Namespace, Name: service.Name}
if proxier.serviceChanges.update(&namespacedName, service, nil) && proxier.isInitialized() {
proxier.syncRunner.Run()
}
}
func (proxier *Proxier) OnServiceSynced() {
proxier.mu.Lock()
proxier.servicesSynced = true
proxier.setInitialized(proxier.servicesSynced && proxier.endpointsSynced)
proxier.mu.Unlock()
// Sync unconditionally - this is called once per lifetime.
proxier.syncProxyRules()
}
func shouldSkipService(svcName types.NamespacedName, service *api.Service) bool {
// if ClusterIP is "None" or empty, skip proxying
if !helper.IsServiceIPSet(service) {
glog.V(3).Infof("Skipping service %s due to clusterIP = %q", svcName, service.Spec.ClusterIP)
return true
}
// Even if ClusterIP is set, ServiceTypeExternalName services don't get proxied
if service.Spec.Type == api.ServiceTypeExternalName {
glog.V(3).Infof("Skipping service %s due to Type=ExternalName", svcName)
return true
}
return false
}
// <serviceMap> is updated by this function (based on the given changes).
// <changes> map is cleared after applying them.
func updateServiceMap(
serviceMap proxyServiceMap,
changes *serviceChangeMap) (result updateServiceMapResult) {
result.staleServices = sets.NewString()
func() {
changes.lock.Lock()
defer changes.lock.Unlock()
for _, change := range changes.items {
existingPorts := serviceMap.merge(change.current)
serviceMap.unmerge(change.previous, existingPorts, result.staleServices)
}
changes.items = make(map[types.NamespacedName]*serviceChange)
}()
// TODO: If this will appear to be computationally expensive, consider
// computing this incrementally similarly to serviceMap.
result.hcServices = make(map[types.NamespacedName]uint16)
for svcPortName, info := range serviceMap {
if info.healthCheckNodePort != 0 {
result.hcServices[svcPortName.NamespacedName] = uint16(info.healthCheckNodePort)
}
}
return result
}
func (proxier *Proxier) OnEndpointsAdd(endpoints *api.Endpoints) {
namespacedName := types.NamespacedName{Namespace: endpoints.Namespace, Name: endpoints.Name}
if proxier.endpointsChanges.update(&namespacedName, nil, endpoints) && proxier.isInitialized() {
proxier.syncRunner.Run()
}
}
func (proxier *Proxier) OnEndpointsUpdate(oldEndpoints, endpoints *api.Endpoints) {
namespacedName := types.NamespacedName{Namespace: endpoints.Namespace, Name: endpoints.Name}
if proxier.endpointsChanges.update(&namespacedName, oldEndpoints, endpoints) && proxier.isInitialized() {
proxier.syncRunner.Run()
}
}
func (proxier *Proxier) OnEndpointsDelete(endpoints *api.Endpoints) {
namespacedName := types.NamespacedName{Namespace: endpoints.Namespace, Name: endpoints.Name}
if proxier.endpointsChanges.update(&namespacedName, endpoints, nil) && proxier.isInitialized() {
proxier.syncRunner.Run()
}
}
func (proxier *Proxier) OnEndpointsSynced() {
proxier.mu.Lock()
proxier.endpointsSynced = true
proxier.setInitialized(proxier.servicesSynced && proxier.endpointsSynced)
proxier.mu.Unlock()
// Sync unconditionally - this is called once per lifetime.
proxier.syncProxyRules()
}
// <endpointsMap> is updated by this function (based on the given changes).
// <changes> map is cleared after applying them.
func updateEndpointsMap(
endpointsMap proxyEndpointsMap,
changes *endpointsChangeMap,
hostname string) (result updateEndpointMapResult) {
result.staleEndpoints = make(map[endpointServicePair]bool)
result.staleServiceNames = make(map[proxy.ServicePortName]bool)
func() {
changes.lock.Lock()
defer changes.lock.Unlock()
for _, change := range changes.items {
endpointsMap.unmerge(change.previous)
endpointsMap.merge(change.current)
detectStaleConnections(change.previous, change.current, result.staleEndpoints, result.staleServiceNames)
}
changes.items = make(map[types.NamespacedName]*endpointsChange)
}()
if !utilfeature.DefaultFeatureGate.Enabled(features.ExternalTrafficLocalOnly) {
return
}
// TODO: If this will appear to be computationally expensive, consider
// computing this incrementally similarly to endpointsMap.
result.hcEndpoints = make(map[types.NamespacedName]int)
localIPs := getLocalIPs(endpointsMap)
for nsn, ips := range localIPs {
result.hcEndpoints[nsn] = len(ips)
}
return result
}
// <staleEndpoints> and <staleServices> are modified by this function with detected stale connections.
func detectStaleConnections(oldEndpointsMap, newEndpointsMap proxyEndpointsMap, staleEndpoints map[endpointServicePair]bool, staleServiceNames map[proxy.ServicePortName]bool) {
for svcPortName, epList := range oldEndpointsMap {
for _, ep := range epList {
stale := true
for i := range newEndpointsMap[svcPortName] {
if *newEndpointsMap[svcPortName][i] == *ep {
stale = false
break
}
}
if stale {
glog.V(4).Infof("Stale endpoint %v -> %v", svcPortName, ep.endpoint)
staleEndpoints[endpointServicePair{endpoint: ep.endpoint, servicePortName: svcPortName}] = true
}
}
}
for svcPortName, epList := range newEndpointsMap {
// For udp service, if its backend changes from 0 to non-0. There may exist a conntrack entry that could blackhole traffic to the service.
if len(epList) > 0 && len(oldEndpointsMap[svcPortName]) == 0 {
staleServiceNames[svcPortName] = true
}
}
}
func getLocalIPs(endpointsMap proxyEndpointsMap) map[types.NamespacedName]sets.String {
localIPs := make(map[types.NamespacedName]sets.String)
for svcPortName := range endpointsMap {
for _, ep := range endpointsMap[svcPortName] {
if ep.isLocal {
nsn := svcPortName.NamespacedName
if localIPs[nsn] == nil {
localIPs[nsn] = sets.NewString()
}
localIPs[nsn].Insert(ep.IPPart()) // just the IP part
}
}
}
return localIPs
}
// Translates single Endpoints object to proxyEndpointsMap.
// This function is used for incremental updated of endpointsMap.
//
// NOTE: endpoints object should NOT be modified.
func endpointsToEndpointsMap(endpoints *api.Endpoints, hostname string) proxyEndpointsMap {
if endpoints == nil {
return nil
}
endpointsMap := make(proxyEndpointsMap)
// We need to build a map of portname -> all ip:ports for that
// portname. Explode Endpoints.Subsets[*] into this structure.
for i := range endpoints.Subsets {
ss := &endpoints.Subsets[i]
for i := range ss.Ports {
port := &ss.Ports[i]
if port.Port == 0 {
glog.Warningf("ignoring invalid endpoint port %s", port.Name)
continue
}
svcPortName := proxy.ServicePortName{
NamespacedName: types.NamespacedName{Namespace: endpoints.Namespace, Name: endpoints.Name},
Port: port.Name,
}
for i := range ss.Addresses {
addr := &ss.Addresses[i]
if addr.IP == "" {
glog.Warningf("ignoring invalid endpoint port %s with empty host", port.Name)
continue
}
epInfo := &endpointsInfo{
endpoint: net.JoinHostPort(addr.IP, strconv.Itoa(int(port.Port))),
isLocal: addr.NodeName != nil && *addr.NodeName == hostname,
}
endpointsMap[svcPortName] = append(endpointsMap[svcPortName], epInfo)
}
if glog.V(3) {
newEPList := []string{}
for _, ep := range endpointsMap[svcPortName] {
newEPList = append(newEPList, ep.endpoint)
}
glog.Infof("Setting endpoints for %q to %+v", svcPortName, newEPList)
}
}
}
return endpointsMap
}
// Translates single Service object to proxyServiceMap.
//
// NOTE: service object should NOT be modified.
func serviceToServiceMap(service *api.Service) proxyServiceMap {
if service == nil {
return nil
}
svcName := types.NamespacedName{Namespace: service.Namespace, Name: service.Name}
if shouldSkipService(svcName, service) {
return nil
}
serviceMap := make(proxyServiceMap)
for i := range service.Spec.Ports {
servicePort := &service.Spec.Ports[i]
svcPortName := proxy.ServicePortName{NamespacedName: svcName, Port: servicePort.Name}
serviceMap[svcPortName] = newServiceInfo(svcPortName, servicePort, service)
}
return serviceMap
}
// portProtoHash takes the ServicePortName and protocol for a service
// returns the associated 16 character hash. This is computed by hashing (sha256)
// then encoding to base32 and truncating to 16 chars. We do this because IPTables
// Chain Names must be <= 28 chars long, and the longer they are the harder they are to read.
func portProtoHash(servicePortName string, protocol string) string {
hash := sha256.Sum256([]byte(servicePortName + protocol))
encoded := base32.StdEncoding.EncodeToString(hash[:])
return encoded[:16]
}
// servicePortChainName takes the ServicePortName for a service and
// returns the associated iptables chain. This is computed by hashing (sha256)
// then encoding to base32 and truncating with the prefix "KUBE-SVC-".
func servicePortChainName(servicePortName string, protocol string) utiliptables.Chain {
return utiliptables.Chain("KUBE-SVC-" + portProtoHash(servicePortName, protocol))
}
// serviceFirewallChainName takes the ServicePortName for a service and
// returns the associated iptables chain. This is computed by hashing (sha256)
// then encoding to base32 and truncating with the prefix "KUBE-FW-".
func serviceFirewallChainName(servicePortName string, protocol string) utiliptables.Chain {
return utiliptables.Chain("KUBE-FW-" + portProtoHash(servicePortName, protocol))
}
// serviceLBPortChainName takes the ServicePortName for a service and
// returns the associated iptables chain. This is computed by hashing (sha256)
// then encoding to base32 and truncating with the prefix "KUBE-XLB-". We do
// this because IPTables Chain Names must be <= 28 chars long, and the longer
// they are the harder they are to read.
func serviceLBChainName(servicePortName string, protocol string) utiliptables.Chain {
return utiliptables.Chain("KUBE-XLB-" + portProtoHash(servicePortName, protocol))
}
// This is the same as servicePortChainName but with the endpoint included.
func servicePortEndpointChainName(servicePortName string, protocol string, endpoint string) utiliptables.Chain {
hash := sha256.Sum256([]byte(servicePortName + protocol + endpoint))
encoded := base32.StdEncoding.EncodeToString(hash[:])
return utiliptables.Chain("KUBE-SEP-" + encoded[:16])
}
type endpointServicePair struct {
endpoint string
servicePortName proxy.ServicePortName
}
func (esp *endpointServicePair) IPPart() string {
if index := strings.Index(esp.endpoint, ":"); index != -1 {
return esp.endpoint[0:index]
}
return esp.endpoint
}
const noConnectionToDelete = "0 flow entries have been deleted"
// After a UDP endpoint has been removed, we must flush any pending conntrack entries to it, or else we
// risk sending more traffic to it, all of which will be lost (because UDP).
// This assumes the proxier mutex is held
func (proxier *Proxier) deleteEndpointConnections(connectionMap map[endpointServicePair]bool) {
for epSvcPair := range connectionMap {
if svcInfo, ok := proxier.serviceMap[epSvcPair.servicePortName]; ok && svcInfo.protocol == api.ProtocolUDP {
endpointIP := epSvcPair.endpoint[0:strings.Index(epSvcPair.endpoint, ":")]
glog.V(2).Infof("Deleting connection tracking state for service IP %s, endpoint IP %s", svcInfo.clusterIP.String(), endpointIP)
err := utilproxy.ExecConntrackTool(proxier.exec, "-D", "--orig-dst", svcInfo.clusterIP.String(), "--dst-nat", endpointIP, "-p", "udp")
if err != nil && !strings.Contains(err.Error(), noConnectionToDelete) {
// TODO: Better handling for deletion failure. When failure occur, stale udp connection may not get flushed.
// These stale udp connection will keep black hole traffic. Making this a best effort operation for now, since it
// is expensive to baby sit all udp connections to kubernetes services.
glog.Errorf("conntrack return with error: %v", err)
}
}
}
}
// This is where all of the iptables-save/restore calls happen.
// The only other iptables rules are those that are setup in iptablesInit()
// This assumes proxier.mu is NOT held
func (proxier *Proxier) syncProxyRules() {
proxier.mu.Lock()
defer proxier.mu.Unlock()
start := time.Now()
defer func() {
SyncProxyRulesLatency.Observe(sinceInMicroseconds(start))
glog.V(4).Infof("syncProxyRules took %v", time.Since(start))
}()
// don't sync rules till we've received services and endpoints
if !proxier.endpointsSynced || !proxier.servicesSynced {
glog.V(2).Info("Not syncing iptables until Services and Endpoints have been received from master")
return
}