forked from cloudnativelabs/kube-router
/
ecmp_vip.go
388 lines (322 loc) · 10.8 KB
/
ecmp_vip.go
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package routing
import (
"errors"
"fmt"
"strconv"
"time"
"github.com/golang/glog"
"github.com/osrg/gobgp/packet/bgp"
"github.com/osrg/gobgp/table"
v1core "k8s.io/api/core/v1"
"k8s.io/client-go/tools/cache"
)
// bgpAdvertiseVIP advertises the service vip (cluster ip or load balancer ip or external IP) the configured peers
func (nrc *NetworkRoutingController) bgpAdvertiseVIP(vip string) error {
attrs := []bgp.PathAttributeInterface{
bgp.NewPathAttributeOrigin(0),
bgp.NewPathAttributeNextHop(nrc.nodeIP.String()),
}
glog.V(2).Infof("Advertising route: '%s/%s via %s' to peers", vip, strconv.Itoa(32), nrc.nodeIP.String())
_, err := nrc.bgpServer.AddPath("", []*table.Path{table.NewPath(nil, bgp.NewIPAddrPrefix(uint8(32),
vip), false, attrs, time.Now(), false)})
return err
}
// bgpWithdrawVIP unadvertises the service vip
func (nrc *NetworkRoutingController) bgpWithdrawVIP(vip string) error {
glog.V(2).Infof("Withdrawing route: '%s/%s via %s' to peers", vip, strconv.Itoa(32), nrc.nodeIP.String())
pathList := []*table.Path{table.NewPath(nil, bgp.NewIPAddrPrefix(uint8(32),
vip), true, nil, time.Now(), false)}
err := nrc.bgpServer.DeletePath([]byte(nil), 0, "", pathList)
return err
}
func (nrc *NetworkRoutingController) advertiseVIPs(vips []string) {
for _, vip := range vips {
err := nrc.bgpAdvertiseVIP(vip)
if err != nil {
glog.Errorf("error advertising IP: %q, error: %v", vip, err)
}
}
}
func (nrc *NetworkRoutingController) withdrawVIPs(vips []string) {
for _, vip := range vips {
err := nrc.bgpWithdrawVIP(vip)
if err != nil {
glog.Errorf("error withdrawing IP: %q, error: %v", vip, err)
}
}
}
func (nrc *NetworkRoutingController) newServiceEventHandler() cache.ResourceEventHandler {
return cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
nrc.OnServiceUpdate(obj)
},
UpdateFunc: func(oldObj, newObj interface{}) {
nrc.OnServiceUpdate(newObj)
},
DeleteFunc: func(obj interface{}) {
nrc.OnServiceDelete(obj)
},
}
}
// OnServiceUpdate handles the service relates updates from the kubernetes API server
func (nrc *NetworkRoutingController) OnServiceUpdate(obj interface{}) {
svc, ok := obj.(*v1core.Service)
if !ok {
glog.Errorf("cache indexer returned obj that is not type *v1.Service")
return
}
glog.V(1).Infof("Received update to service: %s/%s from watch API", svc.Namespace, svc.Name)
if !nrc.bgpServerStarted {
glog.V(3).Infof("Skipping update to service: %s/%s, controller still performing bootup full-sync", svc.Namespace, svc.Name)
return
}
toAdvertise, toWithdraw, err := nrc.getVIPsForService(svc, true)
if err != nil {
glog.Errorf("error getting routes for service: %s, err: %s", svc.Name, err)
return
}
// update export policies so that new VIP's gets addedd to clusteripprefixsit and vip gets advertised to peers
err = nrc.addExportPolicies()
if err != nil {
glog.Errorf("Error adding BGP export policies: %s", err.Error())
}
if len(toAdvertise) > 0 {
nrc.advertiseVIPs(toAdvertise)
}
if len(toWithdraw) > 0 {
nrc.withdrawVIPs(toWithdraw)
}
}
// OnServiceDelete handles the service delete updates from the kubernetes API server
func (nrc *NetworkRoutingController) OnServiceDelete(obj interface{}) {
if !nrc.bgpServerStarted {
return
}
svc, ok := obj.(*v1core.Service)
if !ok {
glog.Errorf("cache indexer returned obj that is not type *v1.Service")
return
}
glog.V(1).Infof("Received event to delete service: %s/%s from watch API", svc.Namespace, svc.Name)
toAdvertise, toWithdraw, err := nrc.getVIPsForService(svc, true)
if err != nil {
glog.Errorf("failed to get clean up routes for deleted service: %s/%s", svc.Namespace, svc.Name)
return
}
// update export policies so that deleted VIP's gets removed from clusteripprefixsit
err = nrc.addExportPolicies()
if err != nil {
glog.Errorf("Error adding BGP export policies: %s", err.Error())
}
if len(toAdvertise) > 0 {
nrc.withdrawVIPs(toAdvertise)
}
if len(toWithdraw) > 0 {
nrc.withdrawVIPs(toWithdraw)
}
}
func (nrc *NetworkRoutingController) newEndpointsEventHandler() cache.ResourceEventHandler {
return cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
nrc.OnEndpointsAdd(obj)
},
UpdateFunc: func(oldObj, newObj interface{}) {
nrc.OnEndpointsUpdate(newObj)
},
DeleteFunc: func(obj interface{}) {
// don't do anything if an endpoints resource is deleted since
// the service delete event handles route withdrawls
return
},
}
}
// OnEndpointsAdd handles endpoint add events from apiserver
// This method calls OnEndpointsUpdate with the addition of updating BGP export policies
// Calling addExportPolicies here covers the edge case where addExportPolicies fails in
// OnServiceUpdate because the corresponding Endpoint resource for the
// Service was not created yet.
func (nrc *NetworkRoutingController) OnEndpointsAdd(obj interface{}) {
if !nrc.bgpServerStarted {
glog.V(3).Info("Skipping OnAdd event to endpoint, controller still performing bootup full-sync")
return
}
err := nrc.addExportPolicies()
if err != nil {
glog.Errorf("error adding BGP export policies: %s", err)
}
nrc.OnEndpointsUpdate(obj)
}
// OnEndpointsUpdate handles the endpoint updates from the kubernetes API server
func (nrc *NetworkRoutingController) OnEndpointsUpdate(obj interface{}) {
ep, ok := obj.(*v1core.Endpoints)
if !ok {
glog.Errorf("cache indexer returned obj that is not type *v1.Endpoints")
return
}
if isEndpointsForLeaderElection(ep) {
return
}
glog.V(1).Infof("Received update to endpoint: %s/%s from watch API", ep.Namespace, ep.Name)
if !nrc.bgpServerStarted {
glog.V(3).Infof("Skipping update to endpoint: %s/%s, controller still performing bootup full-sync", ep.Namespace, ep.Name)
return
}
svc, err := nrc.serviceForEndpoints(ep)
if err != nil {
glog.Errorf("failed to convert endpoints resource to service: %s", err)
return
}
toAdvertise, toWithdraw, err := nrc.getVIPsForService(svc, true)
if err != nil {
glog.Errorf("error getting routes for service: %s, err: %s", svc.Name, err)
return
}
if len(toAdvertise) > 0 {
nrc.advertiseVIPs(toAdvertise)
}
if len(toWithdraw) > 0 {
nrc.withdrawVIPs(toWithdraw)
}
}
func (nrc *NetworkRoutingController) serviceForEndpoints(ep *v1core.Endpoints) (*v1core.Service, error) {
key, err := cache.MetaNamespaceKeyFunc(ep)
if err != nil {
return nil, err
}
item, exists, err := nrc.svcLister.GetByKey(key)
if err != nil {
return nil, err
}
if !exists {
return nil, fmt.Errorf("service resource doesn't exist for endpoints: %q", ep.Name)
}
svc, ok := item.(*v1core.Service)
if !ok {
return nil, errors.New("type assertion failed for object in service indexer")
}
return svc, nil
}
func (nrc *NetworkRoutingController) getClusterIp(svc *v1core.Service) string {
clusterIp := ""
if svc.Spec.Type == "ClusterIP" || svc.Spec.Type == "NodePort" || svc.Spec.Type == "LoadBalancer" {
// skip headless services
if svc.Spec.ClusterIP != "None" && svc.Spec.ClusterIP != "" {
clusterIp = svc.Spec.ClusterIP
}
}
return clusterIp
}
func (nrc *NetworkRoutingController) getExternalIps(svc *v1core.Service) []string {
externalIpList := make([]string, 0)
if svc.Spec.Type == "ClusterIP" || svc.Spec.Type == "NodePort" {
// skip headless services
if svc.Spec.ClusterIP != "None" && svc.Spec.ClusterIP != "" {
externalIpList = append(externalIpList, svc.Spec.ExternalIPs...)
}
}
return externalIpList
}
func (nrc *NetworkRoutingController) getLoadBalancerIps(svc *v1core.Service) []string {
loadBalancerIpList := make([]string, 0)
if svc.Spec.Type == "LoadBalancer" {
// skip headless services
if svc.Spec.ClusterIP != "None" && svc.Spec.ClusterIP != "" {
_, skiplbips := svc.ObjectMeta.Annotations["kube-router.io/service.skiplbips"]
if !skiplbips {
for _, lbIngress := range svc.Status.LoadBalancer.Ingress {
if len(lbIngress.IP) > 0 {
loadBalancerIpList = append(loadBalancerIpList, lbIngress.IP)
}
}
}
}
}
return loadBalancerIpList
}
func (nrc *NetworkRoutingController) getAllVIPs() ([]string, []string, error) {
return nrc.getVIPs(false)
}
func (nrc *NetworkRoutingController) getActiveVIPs() ([]string, []string, error) {
return nrc.getVIPs(true)
}
func (nrc *NetworkRoutingController) getVIPs(onlyActiveEndpoints bool) ([]string, []string, error) {
toAdvertiseList := make([]string, 0)
toWithdrawList := make([]string, 0)
for _, obj := range nrc.svcLister.List() {
svc := obj.(*v1core.Service)
toAdvertise, toWithdraw, err := nrc.getVIPsForService(svc, onlyActiveEndpoints)
if err != nil {
return nil, nil, err
}
if len(toAdvertise) > 0 {
toAdvertiseList = append(toAdvertiseList, toAdvertise...)
}
if len(toWithdraw) > 0 {
toWithdrawList = append(toWithdrawList, toWithdraw...)
}
}
return toAdvertiseList, toWithdrawList, nil
}
func (nrc *NetworkRoutingController) getVIPsForService(svc *v1core.Service, onlyActiveEndpoints bool) ([]string, []string, error) {
ipList := make([]string, 0)
var err error
nodeHasEndpoints := true
if onlyActiveEndpoints {
_, isLocal := svc.Annotations[svcLocalAnnotation]
if isLocal || svc.Spec.ExternalTrafficPolicy == v1core.ServiceExternalTrafficPolicyTypeLocal {
nodeHasEndpoints, err = nrc.nodeHasEndpointsForService(svc)
if err != nil {
return nil, nil, err
}
}
}
if nrc.advertiseClusterIP {
clusterIp := nrc.getClusterIp(svc)
if clusterIp != "" {
ipList = append(ipList, clusterIp)
}
}
if nrc.advertiseExternalIP {
ipList = append(ipList, nrc.getExternalIps(svc)...)
}
if nrc.advertiseLoadBalancerIP {
ipList = append(ipList, nrc.getLoadBalancerIps(svc)...)
}
if !nodeHasEndpoints {
return nil, ipList, nil
}
return ipList, nil, nil
}
func isEndpointsForLeaderElection(ep *v1core.Endpoints) bool {
_, isLeaderElection := ep.Annotations[LeaderElectionRecordAnnotationKey]
return isLeaderElection
}
// nodeHasEndpointsForService will get the corresponding Endpoints resource for a given Service
// return true if any endpoint addresses has NodeName matching the node name of the route controller
func (nrc *NetworkRoutingController) nodeHasEndpointsForService(svc *v1core.Service) (bool, error) {
// listers for endpoints and services should use the same keys since
// endpoint and service resources share the same object name and namespace
key, err := cache.MetaNamespaceKeyFunc(svc)
if err != nil {
return false, err
}
item, exists, err := nrc.epLister.GetByKey(key)
if err != nil {
return false, err
}
if !exists {
return false, fmt.Errorf("endpoint resource doesn't exist for service: %q", svc.Name)
}
ep, ok := item.(*v1core.Endpoints)
if !ok {
return false, errors.New("failed to convert cache item to Endpoints type")
}
for _, subset := range ep.Subsets {
for _, address := range subset.Addresses {
if *address.NodeName == nrc.nodeName {
return true, nil
}
}
}
return false, nil
}