127 lines
4.7 KiB
Go
127 lines
4.7 KiB
Go
/*
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Copyright 2016 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package healthcheck
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import (
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"fmt"
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"net"
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"net/http"
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"github.com/golang/glog"
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"k8s.io/apimachinery/pkg/types"
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"k8s.io/apimachinery/pkg/util/sets"
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"k8s.io/kubernetes/pkg/client/cache"
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)
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// proxyMutationRequest: Message to request addition/deletion of endpoints for a service
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type proxyMutationRequest struct {
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serviceName types.NamespacedName
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endpointUids *sets.String
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}
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// proxyListenerRequest: Message to request addition/deletion of a service responder on a listening port
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type proxyListenerRequest struct {
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serviceName types.NamespacedName
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listenPort uint16
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add bool
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responseChannel chan bool
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}
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// serviceEndpointsList: A list of endpoints for a service
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type serviceEndpointsList struct {
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serviceName types.NamespacedName
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endpoints *sets.String
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}
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// serviceResponder: Contains net/http datastructures necessary for responding to each Service's health check on its aux nodePort
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type serviceResponder struct {
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serviceName types.NamespacedName
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listenPort uint16
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listener *net.Listener
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server *http.Server
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}
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// proxyHC: Handler structure for health check, endpoint add/delete and service listener add/delete requests
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type proxyHC struct {
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serviceEndpointsMap cache.ThreadSafeStore
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serviceResponderMap map[types.NamespacedName]serviceResponder
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mutationRequestChannel chan *proxyMutationRequest
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listenerRequestChannel chan *proxyListenerRequest
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}
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// handleHealthCheckRequest - received a health check request - lookup and respond to HC.
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func (h *proxyHC) handleHealthCheckRequest(rw http.ResponseWriter, serviceName string) {
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s, ok := h.serviceEndpointsMap.Get(serviceName)
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if !ok {
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glog.V(4).Infof("Service %s not found or has no local endpoints", serviceName)
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sendHealthCheckResponse(rw, http.StatusServiceUnavailable, "No Service Endpoints Found")
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return
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}
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numEndpoints := len(*s.(*serviceEndpointsList).endpoints)
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if numEndpoints > 0 {
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sendHealthCheckResponse(rw, http.StatusOK, fmt.Sprintf("%d Service Endpoints found", numEndpoints))
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return
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}
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sendHealthCheckResponse(rw, http.StatusServiceUnavailable, "0 local Endpoints are alive")
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}
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// handleMutationRequest - receive requests to mutate the table entry for a service
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func (h *proxyHC) handleMutationRequest(req *proxyMutationRequest) {
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numEndpoints := len(*req.endpointUids)
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glog.V(4).Infof("LB service health check mutation request Service: %s - %d Endpoints %v",
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req.serviceName, numEndpoints, (*req.endpointUids).List())
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if numEndpoints == 0 {
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if _, ok := h.serviceEndpointsMap.Get(req.serviceName.String()); ok {
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glog.V(4).Infof("Deleting endpoints map for service %s, all local endpoints gone", req.serviceName.String())
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h.serviceEndpointsMap.Delete(req.serviceName.String())
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}
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return
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}
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var entry *serviceEndpointsList
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e, exists := h.serviceEndpointsMap.Get(req.serviceName.String())
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if exists {
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entry = e.(*serviceEndpointsList)
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if entry.endpoints.Equal(*req.endpointUids) {
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return
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}
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// Compute differences just for printing logs about additions and removals
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deletedEndpoints := entry.endpoints.Difference(*req.endpointUids)
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newEndpoints := req.endpointUids.Difference(*entry.endpoints)
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for _, e := range newEndpoints.List() {
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glog.V(4).Infof("Adding local endpoint %s to LB health check for service %s",
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e, req.serviceName.String())
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}
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for _, d := range deletedEndpoints.List() {
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glog.V(4).Infof("Deleted endpoint %s from service %s LB health check (%d endpoints left)",
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d, req.serviceName.String(), len(*entry.endpoints))
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}
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}
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entry = &serviceEndpointsList{serviceName: req.serviceName, endpoints: req.endpointUids}
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h.serviceEndpointsMap.Add(req.serviceName.String(), entry)
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}
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// proxyHealthCheckRequest - Factory method to instantiate the health check handler
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func proxyHealthCheckFactory() *proxyHC {
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glog.V(2).Infof("Initializing kube-proxy health checker")
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phc := &proxyHC{
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serviceEndpointsMap: cache.NewThreadSafeStore(cache.Indexers{}, cache.Indices{}),
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serviceResponderMap: make(map[types.NamespacedName]serviceResponder),
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mutationRequestChannel: make(chan *proxyMutationRequest, 1024),
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listenerRequestChannel: make(chan *proxyListenerRequest, 1024),
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}
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return phc
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}
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