// SyncHostports gathers all hostports on node and setup iptables rules enable them. And finally clean up stale hostports
func (h *handler) SyncHostports(natInterfaceName string, activePods []*ActivePod) error {
start := time.Now()
defer func() {
glog.V(4).Infof("syncHostportsRules took %v", time.Since(start))
}()
containerPortMap, err := gatherAllHostports(activePods)
if err != nil {
return err
}
glog.V(4).Info("Ensuring kubelet hostport chains")
// Ensure kubeHostportChain
if _, err := h.iptables.EnsureChain(utiliptables.TableNAT, kubeHostportsChain); err != nil {
return fmt.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, kubeHostportsChain, err)
}
tableChainsNeedJumpServices := []struct {
table utiliptables.Table
chain utiliptables.Chain
}{
{utiliptables.TableNAT, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainPrerouting},
}
args := []string{"-m", "comment", "--comment", "kube hostport portals",
"-m", "addrtype", "--dst-type", "LOCAL",
"-j", string(kubeHostportsChain)}
for _, tc := range tableChainsNeedJumpServices {
if _, err := h.iptables.EnsureRule(utiliptables.Prepend, tc.table, tc.chain, args...); err != nil {
return fmt.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", tc.table, tc.chain, kubeHostportsChain, err)
}
}
// Need to SNAT traffic from localhost
args = []string{"-m", "comment", "--comment", "SNAT for localhost access to hostports", "-o", natInterfaceName, "-s", "127.0.0.0/8", "-j", "MASQUERADE"}
if _, err := h.iptables.EnsureRule(utiliptables.Append, utiliptables.TableNAT, utiliptables.ChainPostrouting, args...); err != nil {
return fmt.Errorf("Failed to ensure that %s chain %s jumps to MASQUERADE: %v", utiliptables.TableNAT, utiliptables.ChainPostrouting, err)
}
// Get iptables-save output so we can check for existing chains and rules.
// This will be a map of chain name to chain with rules as stored in iptables-save/iptables-restore
existingNATChains := make(map[utiliptables.Chain]string)
iptablesSaveRaw, err := h.iptables.Save(utiliptables.TableNAT)
if err != nil { // if we failed to get any rules
glog.Errorf("Failed to execute iptables-save, syncing all rules: %v", err)
} else { // otherwise parse the output
existingNATChains = utiliptables.GetChainLines(utiliptables.TableNAT, iptablesSaveRaw)
}
natChains := bytes.NewBuffer(nil)
natRules := bytes.NewBuffer(nil)
writeLine(natChains, "*nat")
// Make sure we keep stats for the top-level chains, if they existed
// (which most should have because we created them above).
if chain, ok := existingNATChains[kubeHostportsChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(kubeHostportsChain))
}
// Accumulate NAT chains to keep.
activeNATChains := map[utiliptables.Chain]bool{} // use a map as a set
for containerPort, target := range containerPortMap {
protocol := strings.ToLower(string(containerPort.Protocol))
hostportChain := hostportChainName(containerPort, target.podFullName)
if chain, ok := existingNATChains[hostportChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(hostportChain))
}
activeNATChains[hostportChain] = true
// Redirect to hostport chain
args := []string{
"-A", string(kubeHostportsChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s hostport %d"`, target.podFullName, containerPort.HostPort),
"-m", protocol, "-p", protocol,
"--dport", fmt.Sprintf("%d", containerPort.HostPort),
"-j", string(hostportChain),
}
writeLine(natRules, args...)
// Assuming kubelet is syncing iptables KUBE-MARK-MASQ chain
// If the request comes from the pod that is serving the hostport, then SNAT
args = []string{
"-A", string(hostportChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s hostport %d"`, target.podFullName, containerPort.HostPort),
"-s", target.podIP, "-j", string(iptablesproxy.KubeMarkMasqChain),
}
writeLine(natRules, args...)
// Create hostport chain to DNAT traffic to final destination
// IPTables will maintained the stats for this chain
args = []string{
"-A", string(hostportChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s hostport %d"`, target.podFullName, containerPort.HostPort),
"-m", protocol, "-p", protocol,
"-j", "DNAT", fmt.Sprintf("--to-destination=%s:%d", target.podIP, containerPort.ContainerPort),
}
writeLine(natRules, args...)
}
// Delete chains no longer in use.
for chain := range existingNATChains {
if !activeNATChains[chain] {
chainString := string(chain)
if !strings.HasPrefix(chainString, kubeHostportChainPrefix) {
// Ignore chains that aren't ours.
continue
}
// We must (as per iptables) write a chain-line for it, which has
// the nice effect of flushing the chain. Then we can remove the
// chain.
writeLine(natChains, existingNATChains[chain])
writeLine(natRules, "-X", chainString)
}
}
writeLine(natRules, "COMMIT")
natLines := append(natChains.Bytes(), natRules.Bytes()...)
glog.V(3).Infof("Restoring iptables rules: %s", natLines)
err = h.iptables.RestoreAll(natLines, utiliptables.NoFlushTables, utiliptables.RestoreCounters)
if err != nil {
return fmt.Errorf("Failed to execute iptables-restore: %v", err)
}
h.cleanupHostportMap(containerPortMap)
return nil
}
// This is where all of the iptables-save/restore calls happen.
// The only other iptables rules are those that are setup in iptablesInit()
// assumes proxier.mu is held
func (proxier *Proxier) syncProxyRules() {
start := time.Now()
defer func() {
glog.V(4).Infof("syncProxyRules took %v", time.Since(start))
}()
// don't sync rules till we've received services and endpoints
if !proxier.haveReceivedEndpointsUpdate || !proxier.haveReceivedServiceUpdate {
glog.V(2).Info("Not syncing iptables until Services and Endpoints have been received from master")
return
}
glog.V(3).Infof("Syncing iptables rules")
// Create and link the kube services chain.
{
tablesNeedServicesChain := []utiliptables.Table{utiliptables.TableFilter, utiliptables.TableNAT}
for _, table := range tablesNeedServicesChain {
if _, err := proxier.iptables.EnsureChain(table, kubeServicesChain); err != nil {
glog.Errorf("Failed to ensure that %s chain %s exists: %v", table, kubeServicesChain, err)
return
}
}
tableChainsNeedJumpServices := []struct {
table utiliptables.Table
chain utiliptables.Chain
}{
{utiliptables.TableFilter, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainPrerouting},
}
comment := "kubernetes service portals"
args := []string{"-m", "comment", "--comment", comment, "-j", string(kubeServicesChain)}
for _, tc := range tableChainsNeedJumpServices {
if _, err := proxier.iptables.EnsureRule(utiliptables.Prepend, tc.table, tc.chain, args...); err != nil {
glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", tc.table, tc.chain, kubeServicesChain, err)
return
}
}
}
// Create and link the kube postrouting chain.
{
if _, err := proxier.iptables.EnsureChain(utiliptables.TableNAT, kubePostroutingChain); err != nil {
glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, kubePostroutingChain, err)
return
}
comment := "kubernetes postrouting rules"
args := []string{"-m", "comment", "--comment", comment, "-j", string(kubePostroutingChain)}
if _, err := proxier.iptables.EnsureRule(utiliptables.Prepend, utiliptables.TableNAT, utiliptables.ChainPostrouting, args...); err != nil {
glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableNAT, utiliptables.ChainPostrouting, kubePostroutingChain, err)
return
}
}
// Get iptables-save output so we can check for existing chains and rules.
// This will be a map of chain name to chain with rules as stored in iptables-save/iptables-restore
existingFilterChains := make(map[utiliptables.Chain]string)
iptablesSaveRaw, err := proxier.iptables.Save(utiliptables.TableFilter)
if err != nil { // if we failed to get any rules
glog.Errorf("Failed to execute iptables-save, syncing all rules: %v", err)
} else { // otherwise parse the output
existingFilterChains = utiliptables.GetChainLines(utiliptables.TableFilter, iptablesSaveRaw)
}
existingNATChains := make(map[utiliptables.Chain]string)
iptablesSaveRaw, err = proxier.iptables.Save(utiliptables.TableNAT)
if err != nil { // if we failed to get any rules
glog.Errorf("Failed to execute iptables-save, syncing all rules: %v", err)
} else { // otherwise parse the output
existingNATChains = utiliptables.GetChainLines(utiliptables.TableNAT, iptablesSaveRaw)
}
filterChains := bytes.NewBuffer(nil)
filterRules := bytes.NewBuffer(nil)
natChains := bytes.NewBuffer(nil)
natRules := bytes.NewBuffer(nil)
// Write table headers.
writeLine(filterChains, "*filter")
writeLine(natChains, "*nat")
// Make sure we keep stats for the top-level chains, if they existed
// (which most should have because we created them above).
if chain, ok := existingFilterChains[kubeServicesChain]; ok {
writeLine(filterChains, chain)
} else {
writeLine(filterChains, utiliptables.MakeChainLine(kubeServicesChain))
}
if chain, ok := existingNATChains[kubeServicesChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(kubeServicesChain))
}
if chain, ok := existingNATChains[kubeNodePortsChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(kubeNodePortsChain))
}
if chain, ok := existingNATChains[kubePostroutingChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(kubePostroutingChain))
}
if chain, ok := existingNATChains[KubeMarkMasqChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(KubeMarkMasqChain))
}
// Install the kubernetes-specific postrouting rules. We use a whole chain for
// this so that it is easier to flush and change, for example if the mark
// value should ever change.
writeLine(natRules, []string{
"-A", string(kubePostroutingChain),
"-m", "comment", "--comment", `"kubernetes service traffic requiring SNAT"`,
"-m", "mark", "--mark", proxier.masqueradeMark,
"-j", "MASQUERADE",
}...)
// Install the kubernetes-specific masquerade mark rule. We use a whole chain for
// this so that it is easier to flush and change, for example if the mark
// value should ever change.
writeLine(natRules, []string{
"-A", string(KubeMarkMasqChain),
"-j", "MARK", "--set-xmark", proxier.masqueradeMark,
}...)
// Accumulate NAT chains to keep.
activeNATChains := map[utiliptables.Chain]bool{} // use a map as a set
// Accumulate the set of local ports that we will be holding open once this update is complete
replacementPortsMap := map[localPort]closeable{}
// Build rules for each service.
for svcName, svcInfo := range proxier.serviceMap {
protocol := strings.ToLower(string(svcInfo.protocol))
// Create the per-service chain, retaining counters if possible.
svcChain := servicePortChainName(svcName, protocol)
if chain, ok := existingNATChains[svcChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(svcChain))
}
activeNATChains[svcChain] = true
svcXlbChain := serviceLBChainName(svcName, protocol)
if svcInfo.onlyNodeLocalEndpoints {
// Only for services with the externalTraffic annotation set to OnlyLocal
// create the per-service LB chain, retaining counters if possible.
if lbChain, ok := existingNATChains[svcXlbChain]; ok {
writeLine(natChains, lbChain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(svcXlbChain))
}
activeNATChains[svcXlbChain] = true
}
// Capture the clusterIP.
args := []string{
"-A", string(kubeServicesChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s cluster IP"`, svcName.String()),
"-m", protocol, "-p", protocol,
"-d", fmt.Sprintf("%s/32", svcInfo.clusterIP.String()),
"--dport", fmt.Sprintf("%d", svcInfo.port),
}
if proxier.masqueradeAll {
writeLine(natRules, append(args, "-j", string(KubeMarkMasqChain))...)
}
if len(proxier.clusterCIDR) > 0 {
writeLine(natRules, append(args, "! -s", proxier.clusterCIDR, "-j", string(KubeMarkMasqChain))...)
}
writeLine(natRules, append(args, "-j", string(svcChain))...)
// Capture externalIPs.
for _, externalIP := range svcInfo.externalIPs {
// If the "external" IP happens to be an IP that is local to this
// machine, hold the local port open so no other process can open it
// (because the socket might open but it would never work).
if local, err := isLocalIP(externalIP); err != nil {
glog.Errorf("can't determine if IP is local, assuming not: %v", err)
} else if local {
lp := localPort{
desc: "externalIP for " + svcName.String(),
ip: externalIP,
port: svcInfo.port,
protocol: protocol,
}
if proxier.portsMap[lp] != nil {
glog.V(4).Infof("Port %s was open before and is still needed", lp.String())
replacementPortsMap[lp] = proxier.portsMap[lp]
} else {
socket, err := openLocalPort(&lp)
if err != nil {
glog.Errorf("can't open %s, skipping this externalIP: %v", lp.String(), err)
continue
}
replacementPortsMap[lp] = socket
}
} // We're holding the port, so it's OK to install iptables rules.
args := []string{
"-A", string(kubeServicesChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s external IP"`, svcName.String()),
"-m", protocol, "-p", protocol,
"-d", fmt.Sprintf("%s/32", externalIP),
"--dport", fmt.Sprintf("%d", svcInfo.port),
}
// We have to SNAT packets to external IPs.
writeLine(natRules, append(args, "-j", string(KubeMarkMasqChain))...)
// Allow traffic for external IPs that does not come from a bridge (i.e. not from a container)
// nor from a local process to be forwarded to the service.
// This rule roughly translates to "all traffic from off-machine".
// This is imperfect in the face of network plugins that might not use a bridge, but we can revisit that later.
externalTrafficOnlyArgs := append(args,
"-m", "physdev", "!", "--physdev-is-in",
"-m", "addrtype", "!", "--src-type", "LOCAL")
writeLine(natRules, append(externalTrafficOnlyArgs, "-j", string(svcChain))...)
dstLocalOnlyArgs := append(args, "-m", "addrtype", "--dst-type", "LOCAL")
// Allow traffic bound for external IPs that happen to be recognized as local IPs to stay local.
// This covers cases like GCE load-balancers which get added to the local routing table.
writeLine(natRules, append(dstLocalOnlyArgs, "-j", string(svcChain))...)
}
// Capture load-balancer ingress.
for _, ingress := range svcInfo.loadBalancerStatus.Ingress {
if ingress.IP != "" {
// create service firewall chain
fwChain := serviceFirewallChainName(svcName, protocol)
if chain, ok := existingNATChains[fwChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(fwChain))
}
activeNATChains[fwChain] = true
// The service firewall rules are created based on ServiceSpec.loadBalancerSourceRanges field.
// This currently works for loadbalancers that preserves source ips.
// For loadbalancers which direct traffic to service NodePort, the firewall rules will not apply.
args := []string{
"-A", string(kubeServicesChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s loadbalancer IP"`, svcName.String()),
"-m", protocol, "-p", protocol,
"-d", fmt.Sprintf("%s/32", ingress.IP),
"--dport", fmt.Sprintf("%d", svcInfo.port),
}
// jump to service firewall chain
writeLine(natRules, append(args, "-j", string(fwChain))...)
args = []string{
"-A", string(fwChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s loadbalancer IP"`, svcName.String()),
}
// Each source match rule in the FW chain may jump to either the SVC or the XLB chain
chosenChain := svcXlbChain
// If we are proxying globally, we need to masquerade in case we cross nodes.
// If we are proxying only locally, we can retain the source IP.
if !svcInfo.onlyNodeLocalEndpoints {
writeLine(natRules, append(args, "-j", string(KubeMarkMasqChain))...)
chosenChain = svcChain
}
if len(svcInfo.loadBalancerSourceRanges) == 0 {
// allow all sources, so jump directly to the KUBE-SVC or KUBE-XLB chain
writeLine(natRules, append(args, "-j", string(chosenChain))...)
} else {
// firewall filter based on each source range
allowFromNode := false
for _, src := range svcInfo.loadBalancerSourceRanges {
writeLine(natRules, append(args, "-s", src, "-j", string(chosenChain))...)
// ignore error because it has been validated
_, cidr, _ := net.ParseCIDR(src)
if cidr.Contains(proxier.nodeIP) {
allowFromNode = true
}
}
// generally, ip route rule was added to intercept request to loadbalancer vip from the
// loadbalancer's backend hosts. In this case, request will not hit the loadbalancer but loop back directly.
// Need to add the following rule to allow request on host.
if allowFromNode {
writeLine(natRules, append(args, "-s", fmt.Sprintf("%s/32", ingress.IP), "-j", string(chosenChain))...)
}
}
// If the packet was able to reach the end of firewall chain, then it did not get DNATed.
// It means the packet cannot go thru the firewall, then mark it for DROP
writeLine(natRules, append(args, "-j", string(KubeMarkDropChain))...)
}
}
// Capture nodeports. If we had more than 2 rules it might be
// worthwhile to make a new per-service chain for nodeport rules, but
// with just 2 rules it ends up being a waste and a cognitive burden.
if svcInfo.nodePort != 0 {
// Hold the local port open so no other process can open it
// (because the socket might open but it would never work).
lp := localPort{
desc: "nodePort for " + svcName.String(),
ip: "",
port: svcInfo.nodePort,
protocol: protocol,
}
if proxier.portsMap[lp] != nil {
glog.V(4).Infof("Port %s was open before and is still needed", lp.String())
replacementPortsMap[lp] = proxier.portsMap[lp]
} else {
socket, err := openLocalPort(&lp)
if err != nil {
glog.Errorf("can't open %s, skipping this nodePort: %v", lp.String(), err)
continue
}
replacementPortsMap[lp] = socket
} // We're holding the port, so it's OK to install iptables rules.
args := []string{
"-A", string(kubeNodePortsChain),
"-m", "comment", "--comment", svcName.String(),
"-m", protocol, "-p", protocol,
"--dport", fmt.Sprintf("%d", svcInfo.nodePort),
}
// Nodeports need SNAT.
writeLine(natRules, append(args, "-j", string(KubeMarkMasqChain))...)
// Jump to the service chain.
writeLine(natRules, append(args, "-j", string(svcChain))...)
}
// If the service has no endpoints then reject packets.
if len(proxier.endpointsMap[svcName]) == 0 {
writeLine(filterRules,
"-A", string(kubeServicesChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s has no endpoints"`, svcName.String()),
"-m", protocol, "-p", protocol,
"-d", fmt.Sprintf("%s/32", svcInfo.clusterIP.String()),
"--dport", fmt.Sprintf("%d", svcInfo.port),
"-j", "REJECT",
)
continue
}
// Generate the per-endpoint chains. We do this in multiple passes so we
// can group rules together.
// These two slices parallel each other - keep in sync
endpoints := make([]*endpointsInfo, 0)
endpointChains := make([]utiliptables.Chain, 0)
for _, ep := range proxier.endpointsMap[svcName] {
endpoints = append(endpoints, ep)
endpointChain := servicePortEndpointChainName(svcName, protocol, ep.ip)
endpointChains = append(endpointChains, endpointChain)
// Create the endpoint chain, retaining counters if possible.
if chain, ok := existingNATChains[utiliptables.Chain(endpointChain)]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(endpointChain))
}
activeNATChains[endpointChain] = true
}
// First write session affinity rules, if applicable.
if svcInfo.sessionAffinityType == api.ServiceAffinityClientIP {
for _, endpointChain := range endpointChains {
writeLine(natRules,
"-A", string(svcChain),
"-m", "comment", "--comment", svcName.String(),
"-m", "recent", "--name", string(endpointChain),
"--rcheck", "--seconds", fmt.Sprintf("%d", svcInfo.stickyMaxAgeSeconds), "--reap",
"-j", string(endpointChain))
}
}
// Now write loadbalancing & DNAT rules.
n := len(endpointChains)
for i, endpointChain := range endpointChains {
// Balancing rules in the per-service chain.
args := []string{
"-A", string(svcChain),
"-m", "comment", "--comment", svcName.String(),
}
if i < (n - 1) {
// Each rule is a probabilistic match.
args = append(args,
"-m", "statistic",
"--mode", "random",
"--probability", fmt.Sprintf("%0.5f", 1.0/float64(n-i)))
}
// The final (or only if n == 1) rule is a guaranteed match.
args = append(args, "-j", string(endpointChain))
writeLine(natRules, args...)
// Rules in the per-endpoint chain.
args = []string{
"-A", string(endpointChain),
"-m", "comment", "--comment", svcName.String(),
}
// Handle traffic that loops back to the originator with SNAT.
writeLine(natRules, append(args,
"-s", fmt.Sprintf("%s/32", strings.Split(endpoints[i].ip, ":")[0]),
"-j", string(KubeMarkMasqChain))...)
// Update client-affinity lists.
if svcInfo.sessionAffinityType == api.ServiceAffinityClientIP {
args = append(args, "-m", "recent", "--name", string(endpointChain), "--set")
}
// DNAT to final destination.
args = append(args, "-m", protocol, "-p", protocol, "-j", "DNAT", "--to-destination", endpoints[i].ip)
writeLine(natRules, args...)
}
// The logic below this applies only if this service is marked as OnlyLocal
if !svcInfo.onlyNodeLocalEndpoints {
continue
}
// Now write ingress loadbalancing & DNAT rules only for services that have a localOnly annotation
// TODO - This logic may be combinable with the block above that creates the svc balancer chain
localEndpoints := make([]*endpointsInfo, 0)
localEndpointChains := make([]utiliptables.Chain, 0)
for i := range endpointChains {
if endpoints[i].localEndpoint {
// These slices parallel each other; must be kept in sync
localEndpoints = append(localEndpoints, endpoints[i])
localEndpointChains = append(localEndpointChains, endpointChains[i])
}
}
numLocalEndpoints := len(localEndpointChains)
if numLocalEndpoints == 0 {
// Blackhole all traffic since there are no local endpoints
args := []string{
"-A", string(svcXlbChain),
"-m", "comment", "--comment",
fmt.Sprintf(`"%s has no local endpoints"`, svcName.String()),
"-j",
string(KubeMarkDropChain),
}
writeLine(natRules, args...)
} else {
// Setup probability filter rules only over local endpoints
for i, endpointChain := range localEndpointChains {
// Balancing rules in the per-service chain.
args := []string{
"-A", string(svcXlbChain),
"-m", "comment", "--comment",
fmt.Sprintf(`"Balancing rule %d for %s"`, i, svcName.String()),
}
if i < (numLocalEndpoints - 1) {
// Each rule is a probabilistic match.
args = append(args,
"-m", "statistic",
"--mode", "random",
"--probability", fmt.Sprintf("%0.5f", 1.0/float64(numLocalEndpoints-i)))
}
// The final (or only if n == 1) rule is a guaranteed match.
args = append(args, "-j", string(endpointChain))
writeLine(natRules, args...)
}
}
}
// Delete chains no longer in use.
for chain := range existingNATChains {
if !activeNATChains[chain] {
chainString := string(chain)
if !strings.HasPrefix(chainString, "KUBE-SVC-") && !strings.HasPrefix(chainString, "KUBE-SEP-") && !strings.HasPrefix(chainString, "KUBE-FW-") && !strings.HasPrefix(chainString, "KUBE-XLB-") {
// Ignore chains that aren't ours.
continue
}
// We must (as per iptables) write a chain-line for it, which has
// the nice effect of flushing the chain. Then we can remove the
// chain.
writeLine(natChains, existingNATChains[chain])
writeLine(natRules, "-X", chainString)
}
}
// Finally, tail-call to the nodeports chain. This needs to be after all
// other service portal rules.
writeLine(natRules,
"-A", string(kubeServicesChain),
"-m", "comment", "--comment", `"kubernetes service nodeports; NOTE: this must be the last rule in this chain"`,
"-m", "addrtype", "--dst-type", "LOCAL",
"-j", string(kubeNodePortsChain))
// Write the end-of-table markers.
writeLine(filterRules, "COMMIT")
writeLine(natRules, "COMMIT")
// Sync rules.
// NOTE: NoFlushTables is used so we don't flush non-kubernetes chains in the table.
filterLines := append(filterChains.Bytes(), filterRules.Bytes()...)
natLines := append(natChains.Bytes(), natRules.Bytes()...)
lines := append(filterLines, natLines...)
glog.V(3).Infof("Restoring iptables rules: %s", lines)
err = proxier.iptables.RestoreAll(lines, utiliptables.NoFlushTables, utiliptables.RestoreCounters)
if err != nil {
glog.Errorf("Failed to execute iptables-restore: %v", err)
// Revert new local ports.
revertPorts(replacementPortsMap, proxier.portsMap)
return
}
// Close old local ports and save new ones.
for k, v := range proxier.portsMap {
if replacementPortsMap[k] == nil {
v.Close()
}
}
proxier.portsMap = replacementPortsMap
}