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restrict externalTrafficPolicy=Local interpretation only to NodePort …
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…and LoadBalancer services (#819)

* restrict externalTrafficPolicy=Local interpretation only to NodePort and LoadBalancer services

Fixes #818

* refactoring service controller sync() logic to be more modular
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@murali-reddy
murali-reddy committed Jan 22, 2020
1 parent c160e90 commit 27ec314
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Showing 2 changed files with 517 additions and 371 deletions.
371 changes: 0 additions & 371 deletions pkg/controllers/proxy/network_services_controller.go
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Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,6 @@ import (
"github.com/vishvananda/netns"
"golang.org/x/net/context"
api "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/cache"
)
Expand Down Expand Up @@ -835,376 +834,6 @@ func hasActiveEndpoints(svc *serviceInfo, endpoints []endpointsInfo) bool {
return false
}

// sync the ipvs service and server details configured to reflect the desired state of services and endpoint
// as learned from services and endpoints information from the api server
func (nsc *NetworkServicesController) syncIpvsServices(serviceInfoMap serviceInfoMap, endpointsInfoMap endpointsInfoMap) error {
var ipvsSvcs []*ipvs.Service
start := time.Now()

defer func() {
endTime := time.Since(start)
if nsc.MetricsEnabled {
metrics.ControllerIpvsServicesSyncTime.Observe(endTime.Seconds())
}
glog.V(1).Infof("sync ipvs services took %v", endTime)
}()

dummyVipInterface, err := nsc.ln.getKubeDummyInterface()
if err != nil {
return errors.New("Failed creating dummy interface: " + err.Error())
}

glog.V(1).Infof("Setting up policy routing required for Direct Server Return functionality.")
err = nsc.ln.setupPolicyRoutingForDSR()
if err != nil {
return errors.New("Failed setup PBR for DSR due to: " + err.Error())
}
glog.V(1).Infof("Custom routing table " + customDSRRouteTableName + " required for Direct Server Return is setup as expected.")

glog.V(1).Infof("Setting up custom route table required to add routes for external IP's.")
err = nsc.ln.setupRoutesForExternalIPForDSR(serviceInfoMap)
if err != nil {
glog.Errorf("Failed setup custom routing table required to add routes for external IP's due to: " + err.Error())
return errors.New("Failed setup custom routing table required to add routes for external IP's due to: " + err.Error())
}
glog.V(1).Infof("Custom routing table " + externalIPRouteTableName + " required for Direct Server Return is setup as expected.")

// map of active services and service endpoints
activeServiceEndpointMap := make(map[string][]string)

ipvsSvcs, err = nsc.ln.ipvsGetServices()
if err != nil {
return errors.New("Failed get list of IPVS services due to: " + err.Error())
}

for k, svc := range serviceInfoMap {
var protocol uint16

switch svc.protocol {
case "tcp":
protocol = syscall.IPPROTO_TCP
case "udp":
protocol = syscall.IPPROTO_UDP
default:
protocol = syscall.IPPROTO_NONE
}

endpoints := endpointsInfoMap[k]

if svc.local && !hasActiveEndpoints(svc, endpoints) {
glog.V(1).Infof("Skipping service %s/%s as it does not have active endpoints\n", svc.namespace, svc.name)
continue
}

// assign cluster IP of the service to the dummy interface so that its routable from the pod's on the node
err := nsc.ln.ipAddrAdd(dummyVipInterface, svc.clusterIP.String(), true)
if err != nil {
continue
}

// create IPVS service for the service to be exposed through the cluster ip
ipvsClusterVipSvc, err := nsc.ln.ipvsAddService(ipvsSvcs, svc.clusterIP, protocol, uint16(svc.port), svc.sessionAffinity, svc.scheduler, svc.flags)
if err != nil {
glog.Errorf("Failed to create ipvs service for cluster ip: %s", err.Error())
continue
}
var clusterServiceId = generateIpPortId(svc.clusterIP.String(), svc.protocol, strconv.Itoa(svc.port))
activeServiceEndpointMap[clusterServiceId] = make([]string, 0)

// create IPVS service for the service to be exposed through the nodeport
var ipvsNodeportSvcs []*ipvs.Service

var nodeServiceIds []string

if svc.nodePort != 0 {
if nsc.nodeportBindOnAllIp {
// bind on all interfaces instead
addrs, err := getAllLocalIPs()

if err != nil {
glog.Errorf("Could not get list of system addresses for ipvs services: %s", err.Error())
continue
}

if len(addrs) == 0 {
glog.Errorf("No IP addresses returned for nodeport service creation!")
continue
}

ipvsNodeportSvcs = make([]*ipvs.Service, len(addrs))
nodeServiceIds = make([]string, len(addrs))

for i, addr := range addrs {
ipvsNodeportSvcs[i], err = nsc.ln.ipvsAddService(ipvsSvcs, addr.IP, protocol, uint16(svc.nodePort), svc.sessionAffinity, svc.scheduler, svc.flags)
if err != nil {
glog.Errorf("Failed to create ipvs service for node port due to: %s", err.Error())
continue
}

nodeServiceIds[i] = generateIpPortId(addr.IP.String(), svc.protocol, strconv.Itoa(svc.nodePort))
activeServiceEndpointMap[nodeServiceIds[i]] = make([]string, 0)
}
} else {
ipvsNodeportSvcs = make([]*ipvs.Service, 1)
ipvsNodeportSvcs[0], err = nsc.ln.ipvsAddService(ipvsSvcs, nsc.nodeIP, protocol, uint16(svc.nodePort), svc.sessionAffinity, svc.scheduler, svc.flags)
if err != nil {
glog.Errorf("Failed to create ipvs service for node port due to: %s", err.Error())
continue
}

nodeServiceIds = make([]string, 1)
nodeServiceIds[0] = generateIpPortId(nsc.nodeIP.String(), svc.protocol, strconv.Itoa(svc.nodePort))
activeServiceEndpointMap[nodeServiceIds[0]] = make([]string, 0)
}
}

externalIpServices := make([]externalIPService, 0)
// create IPVS service for the service to be exposed through the external IP's
// For external IP (which are meant for ingress traffic) Kube-router setsup IPVS services
// based on FWMARK to enable Direct server return functionality. DSR requires a director
// without a VIP http://www.austintek.com/LVS/LVS-HOWTO/HOWTO/LVS-HOWTO.routing_to_VIP-less_director.html
// to avoid martian packets
extIPSet := sets.NewString(svc.externalIPs...)
if !svc.skipLbIps {
extIPSet = extIPSet.Union(sets.NewString(svc.loadBalancerIPs...))
}

for _, externalIP := range extIPSet.List() {
var externalIpServiceId string
if svc.directServerReturn && svc.directServerReturnMethod == "tunnel" {
ipvsExternalIPSvc, err := nsc.ln.ipvsAddFWMarkService(net.ParseIP(externalIP), protocol, uint16(svc.port), svc.sessionAffinity, svc.scheduler, svc.flags)
if err != nil {
glog.Errorf("Failed to create ipvs service for External IP: %s due to: %s", externalIP, err.Error())
continue
}
externalIpServices = append(externalIpServices, externalIPService{ipvsSvc: ipvsExternalIPSvc, externalIp: externalIP})
fwMark := generateFwmark(externalIP, svc.protocol, strconv.Itoa(svc.port))
externalIpServiceId = fmt.Sprint(fwMark)

// ensure there is iptables mangle table rule to FWMARK the packet
err = setupMangleTableRule(externalIP, svc.protocol, strconv.Itoa(svc.port), externalIpServiceId)
if err != nil {
glog.Errorf("Failed to setup mangle table rule to FMWARD the traffic to external IP")
continue
}

// ensure VIP less director. we dont assign VIP to any interface
err = nsc.ln.ipAddrDel(dummyVipInterface, externalIP)

// do policy routing to deliver the packet locally so that IPVS can pick the packet
err = routeVIPTrafficToDirector("0x" + fmt.Sprintf("%x", fwMark))
if err != nil {
glog.Errorf("Failed to setup ip rule to lookup traffic to external IP: %s through custom "+
"route table due to %s", externalIP, err.Error())
continue
}
} else {
// ensure director with vip assigned
err := nsc.ln.ipAddrAdd(dummyVipInterface, externalIP, true)
if err != nil && err.Error() != IFACE_HAS_ADDR {
glog.Errorf("Failed to assign external ip %s to dummy interface %s due to %s", externalIP, KUBE_DUMMY_IF, err.Error())
}

// create IPVS service for the service to be exposed through the external ip
ipvsExternalIPSvc, err := nsc.ln.ipvsAddService(ipvsSvcs, net.ParseIP(externalIP), protocol, uint16(svc.port), svc.sessionAffinity, svc.scheduler, svc.flags)
if err != nil {
glog.Errorf("Failed to create ipvs service for external ip: %s due to %s", externalIP, err.Error())
continue
}
externalIpServices = append(externalIpServices, externalIPService{ipvsSvc: ipvsExternalIPSvc, externalIp: externalIP})
externalIpServiceId = generateIpPortId(externalIP, svc.protocol, strconv.Itoa(svc.port))

// ensure there is NO iptables mangle table rule to FWMARK the packet
fwMark := fmt.Sprint(generateFwmark(externalIP, svc.protocol, strconv.Itoa(svc.port)))
err = nsc.ln.cleanupMangleTableRule(externalIP, svc.protocol, strconv.Itoa(svc.port), fwMark)
if err != nil {
glog.Errorf("Failed to verify and cleanup any mangle table rule to FMWARD the traffic to external IP due to " + err.Error())
continue
}
}

activeServiceEndpointMap[externalIpServiceId] = make([]string, 0)
for _, endpoint := range endpoints {
if !svc.local || (svc.local && endpoint.isLocal) {
activeServiceEndpointMap[externalIpServiceId] = append(activeServiceEndpointMap[externalIpServiceId], endpoint.ip)
}
}
}

// add IPVS remote server to the IPVS service
for _, endpoint := range endpoints {
dst := ipvs.Destination{
Address: net.ParseIP(endpoint.ip),
AddressFamily: syscall.AF_INET,
Port: uint16(endpoint.port),
Weight: 1,
}

if !svc.local || (svc.local && endpoint.isLocal) {
err := nsc.ln.ipvsAddServer(ipvsClusterVipSvc, &dst)
if err != nil {
glog.Errorf(err.Error())
} else {
activeServiceEndpointMap[clusterServiceId] = append(activeServiceEndpointMap[clusterServiceId], endpoint.ip)
}
}

if svc.nodePort != 0 {
for i := 0; i < len(ipvsNodeportSvcs); i++ {
if !svc.local || (svc.local && endpoint.isLocal) {
err := nsc.ln.ipvsAddServer(ipvsNodeportSvcs[i], &dst)
if err != nil {
glog.Errorf(err.Error())
} else {
activeServiceEndpointMap[nodeServiceIds[i]] = append(activeServiceEndpointMap[nodeServiceIds[i]], endpoint.ip)
}
}
}
}

for _, externalIpService := range externalIpServices {
if svc.local && !endpoint.isLocal {
continue
}

if svc.directServerReturn && svc.directServerReturnMethod == "tunnel" {
dst.ConnectionFlags = ipvs.ConnectionFlagTunnel
}

// add server to IPVS service
err := nsc.ln.ipvsAddServer(externalIpService.ipvsSvc, &dst)
if err != nil {
glog.Errorf(err.Error())
}

// For now just support IPVS tunnel mode, we can add other ways of DSR in future
if svc.directServerReturn && svc.directServerReturnMethod == "tunnel" {

podObj, err := nsc.getPodObjectForEndpoint(endpoint.ip)
if err != nil {
glog.Errorf("Failed to find endpoint with ip: " + endpoint.ip + ". so skipping peparing endpoint for DSR")
continue
}

// we are only concerned with endpoint pod running on current node
if strings.Compare(podObj.Status.HostIP, nsc.nodeIP.String()) != 0 {
continue
}

containerID := strings.TrimPrefix(podObj.Status.ContainerStatuses[0].ContainerID, "docker://")
if containerID == "" {
glog.Errorf("Failed to find container id for the endpoint with ip: " + endpoint.ip + " so skipping peparing endpoint for DSR")
continue
}

err = nsc.ln.prepareEndpointForDsr(containerID, endpoint.ip, externalIpService.externalIp)
if err != nil {
glog.Errorf("Failed to prepare endpoint %s to do direct server return due to %s", endpoint.ip, err.Error())
}
}
}
}
}

// cleanup stale IPs on dummy interface
glog.V(1).Info("Cleaning up if any, old service IPs on dummy interface")
addrActive := make(map[string]bool)
for k := range activeServiceEndpointMap {
// verify active and its a generateIpPortId() type service
if strings.Contains(k, "-") {
parts := strings.SplitN(k, "-", 3)
addrActive[parts[0]] = true
}
}

var addrs []netlink.Addr
addrs, err = netlink.AddrList(dummyVipInterface, netlink.FAMILY_V4)
if err != nil {
return errors.New("Failed to list dummy interface IPs: " + err.Error())
}
for _, addr := range addrs {
isActive := addrActive[addr.IP.String()]
if !isActive {
glog.V(1).Infof("Found an IP %s which is no longer needed so cleaning up", addr.IP.String())
err := nsc.ln.ipAddrDel(dummyVipInterface, addr.IP.String())
if err != nil {
glog.Errorf("Failed to delete stale IP %s due to: %s",
addr.IP.String(), err.Error())
continue
}
}
}

// cleanup stale ipvs service and servers
glog.V(1).Info("Cleaning up if any, old ipvs service and servers which are no longer needed")
ipvsSvcs, err = nsc.ln.ipvsGetServices()

if err != nil {
return errors.New("Failed to list IPVS services: " + err.Error())
}
var protocol string
for _, ipvsSvc := range ipvsSvcs {
if ipvsSvc.Protocol == syscall.IPPROTO_TCP {
protocol = "tcp"
} else {
protocol = "udp"
}
var key string
if ipvsSvc.Address != nil {
key = generateIpPortId(ipvsSvc.Address.String(), protocol, strconv.Itoa(int(ipvsSvc.Port)))
} else if ipvsSvc.FWMark != 0 {
key = fmt.Sprint(ipvsSvc.FWMark)
} else {
continue
}

endpoints, ok := activeServiceEndpointMap[key]
// Only delete the service if it's not there anymore to prevent flapping
// old: if !ok || len(endpoints) == 0 {
if !ok {
glog.V(1).Infof("Found a IPVS service %s which is no longer needed so cleaning up",
ipvsServiceString(ipvsSvc))
err := nsc.ln.ipvsDelService(ipvsSvc)
if err != nil {
glog.Errorf("Failed to delete stale IPVS service %s due to: %s",
ipvsServiceString(ipvsSvc), err.Error())
continue
}
} else {
dsts, err := nsc.ln.ipvsGetDestinations(ipvsSvc)
if err != nil {
glog.Errorf("Failed to get list of servers from ipvs service")
}
for _, dst := range dsts {
validEp := false
for _, ep := range endpoints {
if ep == dst.Address.String() {
validEp = true
break
}
}
if !validEp {
glog.V(1).Infof("Found a destination %s in service %s which is no longer needed so cleaning up",
ipvsDestinationString(dst), ipvsServiceString(ipvsSvc))
err = nsc.ipvsDeleteDestination(ipvsSvc, dst)
if err != nil {
glog.Errorf("Failed to delete destination %s from ipvs service %s",
ipvsDestinationString(dst), ipvsServiceString(ipvsSvc))
}
}
}
}
}

err = nsc.syncIpvsFirewall()
if err != nil {
glog.Errorf("Error syncing ipvs svc iptables rules: %s", err.Error())
}

glog.V(1).Info("IPVS servers and services are synced to desired state")
return nil
}

func (nsc *NetworkServicesController) getPodObjectForEndpoint(endpointIP string) (*api.Pod, error) {
for _, obj := range nsc.podLister.List() {
pod := obj.(*api.Pod)
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