ingress-nginx-helm/core/pkg/ingress/controller/controller.go

/*
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 controller

import (
	"fmt"
	"os"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/golang/glog"
	"github.com/kylelemons/godebug/pretty"

	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/apis/extensions"
	"k8s.io/kubernetes/pkg/client/cache"
	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
	unversionedcore "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset/typed/core/internalversion"
	"k8s.io/kubernetes/pkg/client/record"
	"k8s.io/kubernetes/pkg/fields"
	"k8s.io/kubernetes/pkg/util/flowcontrol"
	"k8s.io/kubernetes/pkg/util/intstr"

	cache_store "k8s.io/ingress/core/pkg/cache"
	"k8s.io/ingress/core/pkg/ingress"
	"k8s.io/ingress/core/pkg/ingress/annotations/healthcheck"
	"k8s.io/ingress/core/pkg/ingress/annotations/proxy"
	"k8s.io/ingress/core/pkg/ingress/annotations/service"
	"k8s.io/ingress/core/pkg/ingress/defaults"
	"k8s.io/ingress/core/pkg/ingress/resolver"
	"k8s.io/ingress/core/pkg/ingress/status"
	"k8s.io/ingress/core/pkg/k8s"
	ssl "k8s.io/ingress/core/pkg/net/ssl"
	local_strings "k8s.io/ingress/core/pkg/strings"
	"k8s.io/ingress/core/pkg/task"
)

const (
	defUpstreamName          = "upstream-default-backend"
	defServerName            = "_"
	podStoreSyncedPollPeriod = 1 * time.Second
	rootLocation             = "/"

	// ingressClassKey picks a specific "class" for the Ingress. The controller
	// only processes Ingresses with this annotation either unset, or set
	// to either the configured value or the empty string.
	ingressClassKey = "kubernetes.io/ingress.class"
)

var (
	// list of ports that cannot be used by TCP or UDP services
	reservedPorts = []string{"80", "443", "8181", "18080"}
)

// GenericController holds the boilerplate code required to build an Ingress controlller.
type GenericController struct {
	cfg *Configuration

	ingController  *cache.Controller
	endpController *cache.Controller
	svcController  *cache.Controller
	nodeController *cache.Controller
	secrController *cache.Controller
	mapController  *cache.Controller

	ingLister  cache_store.StoreToIngressLister
	svcLister  cache.StoreToServiceLister
	nodeLister cache.StoreToNodeLister
	endpLister cache.StoreToEndpointsLister
	secrLister cache_store.StoreToSecretsLister
	mapLister  cache_store.StoreToConfigmapLister

	annotations annotationExtractor

	recorder record.EventRecorder

	syncQueue *task.Queue

	syncStatus status.Sync

	// local store of SSL certificates
	// (only certificates used in ingress)
	sslCertTracker *sslCertTracker
	// TaskQueue in charge of keep the secrets referenced from Ingress
	// in sync with the files on disk
	secretQueue *task.Queue

	syncRateLimiter flowcontrol.RateLimiter

	// stopLock is used to enforce only a single call to Stop is active.
	// Needed because we allow stopping through an http endpoint and
	// allowing concurrent stoppers leads to stack traces.
	stopLock *sync.Mutex

	stopCh chan struct{}
}

// Configuration contains all the settings required by an Ingress controller
type Configuration struct {
	Client *clientset.Clientset

	ResyncPeriod   time.Duration
	DefaultService string
	IngressClass   string
	Namespace      string
	ConfigMapName  string
	// optional
	TCPConfigMapName string
	// optional
	UDPConfigMapName      string
	DefaultSSLCertificate string
	DefaultHealthzURL     string
	DefaultIngressClass   string
	// optional
	PublishService string
	// Backend is the particular implementation to be used.
	// (for instance NGINX)
	Backend ingress.Controller

	UpdateStatus bool
	ElectionID   string
}

// newIngressController creates an Ingress controller
func newIngressController(config *Configuration) *GenericController {

	eventBroadcaster := record.NewBroadcaster()
	eventBroadcaster.StartLogging(glog.Infof)
	eventBroadcaster.StartRecordingToSink(&unversionedcore.EventSinkImpl{
		Interface: config.Client.Core().Events(config.Namespace),
	})

	ic := GenericController{
		cfg:             config,
		stopLock:        &sync.Mutex{},
		stopCh:          make(chan struct{}),
		syncRateLimiter: flowcontrol.NewTokenBucketRateLimiter(0.1, 1),
		recorder: eventBroadcaster.NewRecorder(api.EventSource{
			Component: "ingress-controller",
		}),
		sslCertTracker: newSSLCertTracker(),
	}

	ic.syncQueue = task.NewTaskQueue(ic.sync)
	ic.secretQueue = task.NewTaskQueue(ic.syncSecret)

	// from here to the end of the method all the code is just boilerplate
	// required to watch Ingress, Secrets, ConfigMaps and Endoints.
	// This is used to detect new content, updates or removals and act accordingly
	ingEventHandler := cache.ResourceEventHandlerFuncs{
		AddFunc: func(obj interface{}) {
			addIng := obj.(*extensions.Ingress)
			if !IsValidClass(addIng, config) {
				glog.Infof("ignoring add for ingress %v based on annotation %v", addIng.Name, ingressClassKey)
				return
			}
			ic.recorder.Eventf(addIng, api.EventTypeNormal, "CREATE", fmt.Sprintf("Ingress %s/%s", addIng.Namespace, addIng.Name))
			ic.syncQueue.Enqueue(obj)
		},
		DeleteFunc: func(obj interface{}) {
			delIng := obj.(*extensions.Ingress)
			if !IsValidClass(delIng, config) {
				glog.Infof("ignoring delete for ingress %v based on annotation %v", delIng.Name, ingressClassKey)
				return
			}
			ic.recorder.Eventf(delIng, api.EventTypeNormal, "DELETE", fmt.Sprintf("Ingress %s/%s", delIng.Namespace, delIng.Name))
			ic.syncQueue.Enqueue(obj)
		},
		UpdateFunc: func(old, cur interface{}) {
			oldIng := old.(*extensions.Ingress)
			curIng := cur.(*extensions.Ingress)
			if !IsValidClass(curIng, config) && !IsValidClass(oldIng, config) {
				return
			}

			if !reflect.DeepEqual(old, cur) {
				upIng := cur.(*extensions.Ingress)
				ic.recorder.Eventf(upIng, api.EventTypeNormal, "UPDATE", fmt.Sprintf("Ingress %s/%s", upIng.Namespace, upIng.Name))
				// the referenced secret is different?
				if diff := pretty.Compare(curIng.Spec.TLS, oldIng.Spec.TLS); diff != "" {
					for _, secretName := range curIng.Spec.TLS {
						secKey := fmt.Sprintf("%v/%v", curIng.Namespace, secretName.SecretName)
						go func() {
							glog.Infof("TLS section in ingress %v/%v changed (secret is now %v)", upIng.Namespace, upIng.Name, secKey)
							// we need to wait until the ingress store is updated
							time.Sleep(10 * time.Second)
							key, err := ic.GetSecret(secKey)
							if err != nil {
								glog.Errorf("unexpected error: %v", err)
							}
							if key != nil {
								ic.secretQueue.Enqueue(key)
							}
						}()
					}
				}
				ic.syncQueue.Enqueue(cur)
			}
		},
	}

	secrEventHandler := cache.ResourceEventHandlerFuncs{
		AddFunc: func(obj interface{}) {
			sec := obj.(*api.Secret)
			ic.secretQueue.Enqueue(sec)
		},
		DeleteFunc: func(obj interface{}) {
			sec := obj.(*api.Secret)
			ic.sslCertTracker.Delete(fmt.Sprintf("%v/%v", sec.Namespace, sec.Name))
		},
		UpdateFunc: func(old, cur interface{}) {
			if !reflect.DeepEqual(old, cur) {
				sec := cur.(*api.Secret)
				ic.secretQueue.Enqueue(sec)
			}
		},
	}

	eventHandler := cache.ResourceEventHandlerFuncs{
		AddFunc: func(obj interface{}) {
			ic.syncQueue.Enqueue(obj)
		},
		DeleteFunc: func(obj interface{}) {
			ic.syncQueue.Enqueue(obj)
		},
		UpdateFunc: func(old, cur interface{}) {
			if !reflect.DeepEqual(old, cur) {
				ic.syncQueue.Enqueue(cur)
			}
		},
	}

	mapEventHandler := cache.ResourceEventHandlerFuncs{
		AddFunc: func(obj interface{}) {
			upCmap := obj.(*api.ConfigMap)
			mapKey := fmt.Sprintf("%s/%s", upCmap.Namespace, upCmap.Name)
			if mapKey == ic.cfg.ConfigMapName {
				glog.V(2).Infof("adding configmap %v to backend", mapKey)
				ic.cfg.Backend.SetConfig(upCmap)
			}
		},
		UpdateFunc: func(old, cur interface{}) {
			if !reflect.DeepEqual(old, cur) {
				upCmap := cur.(*api.ConfigMap)
				mapKey := fmt.Sprintf("%s/%s", upCmap.Namespace, upCmap.Name)
				if mapKey == ic.cfg.ConfigMapName {
					glog.V(2).Infof("updating configmap backend (%v)", mapKey)
					ic.cfg.Backend.SetConfig(upCmap)
				}
				// updates to configuration configmaps can trigger an update
				if mapKey == ic.cfg.ConfigMapName || mapKey == ic.cfg.TCPConfigMapName || mapKey == ic.cfg.UDPConfigMapName {
					ic.recorder.Eventf(upCmap, api.EventTypeNormal, "UPDATE", fmt.Sprintf("ConfigMap %v", mapKey))
					ic.syncQueue.Enqueue(cur)
				}
			}
		},
	}

	ic.ingLister.Store, ic.ingController = cache.NewInformer(
		cache.NewListWatchFromClient(ic.cfg.Client.Extensions().RESTClient(), "ingresses", ic.cfg.Namespace, fields.Everything()),
		&extensions.Ingress{}, ic.cfg.ResyncPeriod, ingEventHandler)

	ic.endpLister.Store, ic.endpController = cache.NewInformer(
		cache.NewListWatchFromClient(ic.cfg.Client.Core().RESTClient(), "endpoints", ic.cfg.Namespace, fields.Everything()),
		&api.Endpoints{}, ic.cfg.ResyncPeriod, eventHandler)

	ic.secrLister.Store, ic.secrController = cache.NewInformer(
		cache.NewListWatchFromClient(ic.cfg.Client.Core().RESTClient(), "secrets", ic.cfg.Namespace, fields.Everything()),
		&api.Secret{}, ic.cfg.ResyncPeriod, secrEventHandler)

	ic.mapLister.Store, ic.mapController = cache.NewInformer(
		cache.NewListWatchFromClient(ic.cfg.Client.Core().RESTClient(), "configmaps", ic.cfg.Namespace, fields.Everything()),
		&api.ConfigMap{}, ic.cfg.ResyncPeriod, mapEventHandler)

	ic.svcLister.Indexer, ic.svcController = cache.NewIndexerInformer(
		cache.NewListWatchFromClient(ic.cfg.Client.Core().RESTClient(), "services", ic.cfg.Namespace, fields.Everything()),
		&api.Service{},
		ic.cfg.ResyncPeriod,
		cache.ResourceEventHandlerFuncs{},
		cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})

	ic.nodeLister.Store, ic.nodeController = cache.NewInformer(
		cache.NewListWatchFromClient(ic.cfg.Client.Core().RESTClient(), "nodes", api.NamespaceAll, fields.Everything()),
		&api.Node{}, ic.cfg.ResyncPeriod, eventHandler)

	if config.UpdateStatus {
		ic.syncStatus = status.NewStatusSyncer(status.Config{
			Client:         config.Client,
			PublishService: ic.cfg.PublishService,
			IngressLister:  ic.ingLister,
			ElectionID:     config.ElectionID,
		})
	} else {
		glog.Warning("Update of ingress status is disabled (flag --update-status=false was specified)")
	}

	ic.annotations = newAnnotationExtractor(ic)

	ic.cfg.Backend.SetListers(ingress.StoreLister{
		Ingress:   ic.ingLister,
		Service:   ic.svcLister,
		Node:      ic.nodeLister,
		Endpoint:  ic.endpLister,
		Secret:    ic.secrLister,
		ConfigMap: ic.mapLister,
	})

	return &ic
}

func (ic *GenericController) controllersInSync() bool {
	return ic.ingController.HasSynced() &&
		ic.svcController.HasSynced() &&
		ic.endpController.HasSynced() &&
		ic.secrController.HasSynced() &&
		ic.mapController.HasSynced()
}

// Info returns information about the backend
func (ic GenericController) Info() *ingress.BackendInfo {
	return ic.cfg.Backend.Info()
}

// IngressClass returns information about the backend
func (ic GenericController) IngressClass() string {
	return ic.cfg.IngressClass
}

// GetDefaultBackend returns the default backend
func (ic GenericController) GetDefaultBackend() defaults.Backend {
	return ic.cfg.Backend.BackendDefaults()
}

// GetSecret searches for a secret in the local secrets Store
func (ic GenericController) GetSecret(name string) (*api.Secret, error) {
	s, exists, err := ic.secrLister.Store.GetByKey(name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, fmt.Errorf("secret %v was not found", name)
	}
	return s.(*api.Secret), nil
}

func (ic *GenericController) getConfigMap(ns, name string) (*api.ConfigMap, error) {
	s, exists, err := ic.mapLister.Store.GetByKey(fmt.Sprintf("%v/%v", ns, name))
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, fmt.Errorf("configmap %v was not found", name)
	}
	return s.(*api.ConfigMap), nil
}

// sync collects all the pieces required to assemble the configuration file and
// then sends the content to the backend (OnUpdate) receiving the populated
// template as response reloading the backend if is required.
func (ic *GenericController) sync(key interface{}) error {
	ic.syncRateLimiter.Accept()

	if ic.syncQueue.IsShuttingDown() {
		return nil
	}

	if !ic.controllersInSync() {
		time.Sleep(podStoreSyncedPollPeriod)
		return fmt.Errorf("deferring sync till endpoints controller has synced")
	}

	upstreams, servers := ic.getBackendServers()
	var passUpstreams []*ingress.SSLPassthroughBackend
	for _, server := range servers {
		if !server.SSLPassthrough {
			continue
		}

		for _, loc := range server.Locations {
			if loc.Path != rootLocation {
				continue
			}
			passUpstreams = append(passUpstreams, &ingress.SSLPassthroughBackend{
				Backend:  loc.Backend,
				Hostname: server.Hostname,
			})
			break
		}
	}

	data, err := ic.cfg.Backend.OnUpdate(ingress.Configuration{
		Backends:            upstreams,
		Servers:             servers,
		TCPEndpoints:        ic.getStreamServices(ic.cfg.TCPConfigMapName, api.ProtocolTCP),
		UDPEndpoints:        ic.getStreamServices(ic.cfg.UDPConfigMapName, api.ProtocolUDP),
		PassthroughBackends: passUpstreams,
	})
	if err != nil {
		return err
	}

	out, reloaded, err := ic.cfg.Backend.Reload(data)
	if err != nil {
		incReloadErrorCount()
		glog.Errorf("unexpected failure restarting the backend: \n%v", string(out))
		return err
	}
	if reloaded {
		glog.Infof("ingress backend successfully reloaded...")
		incReloadCount()
	}
	return nil
}

func (ic *GenericController) getStreamServices(configmapName string, proto api.Protocol) []ingress.L4Service {
	glog.V(3).Infof("obtaining information about stream services of type %v located in configmap %v", proto, configmapName)
	if configmapName == "" {
		// no configmap configured
		return []ingress.L4Service{}
	}

	ns, name, err := k8s.ParseNameNS(configmapName)
	if err != nil {
		glog.Errorf("unexpected error reading configmap %v: %v", name, err)
		return []ingress.L4Service{}
	}

	configmap, err := ic.getConfigMap(ns, name)
	if err != nil {
		glog.Errorf("unexpected error reading configmap %v: %v", name, err)
		return []ingress.L4Service{}
	}

	var svcs []ingress.L4Service
	// k -> port to expose
	// v -> <namespace>/<service name>:<port from service to be used>
	for k, v := range configmap.Data {
		externalPort, err := strconv.Atoi(k)
		if err != nil {
			glog.Warningf("%v is not valid as a TCP/UDP port", k)
			continue
		}

		// this ports used by the backend
		if local_strings.StringInSlice(k, reservedPorts) {
			glog.Warningf("port %v cannot be used for TCP or UDP services. It is reserved for the Ingress controller", k)
			continue
		}

		nsSvcPort := strings.Split(v, ":")
		if len(nsSvcPort) != 2 {
			glog.Warningf("invalid format (namespace/name:port) '%v'", k)
			continue
		}

		nsName := nsSvcPort[0]
		svcPort := nsSvcPort[1]

		svcNs, svcName, err := k8s.ParseNameNS(nsName)
		if err != nil {
			glog.Warningf("%v", err)
			continue
		}

		svcObj, svcExists, err := ic.svcLister.Indexer.GetByKey(nsName)
		if err != nil {
			glog.Warningf("error getting service %v: %v", nsName, err)
			continue
		}

		if !svcExists {
			glog.Warningf("service %v was not found", nsName)
			continue
		}

		svc := svcObj.(*api.Service)

		var endps []ingress.Endpoint
		targetPort, err := strconv.Atoi(svcPort)
		if err != nil {
			glog.V(3).Infof("searching service %v/%v endpoints using the name '%v'", svcNs, svcName, svcPort)
			for _, sp := range svc.Spec.Ports {
				if sp.Name == svcPort {
					endps = ic.getEndpoints(svc, sp.TargetPort, proto, &healthcheck.Upstream{})
					break
				}
			}
		} else {
			// we need to use the TargetPort (where the endpoints are running)
			glog.V(3).Infof("searching service %v/%v endpoints using the target port '%v'", svcNs, svcName, targetPort)
			for _, sp := range svc.Spec.Ports {
				if sp.Port == int32(targetPort) {
					endps = ic.getEndpoints(svc, sp.TargetPort, proto, &healthcheck.Upstream{})
					break
				}
			}
		}

		// stream services cannot contain empty upstreams and there is no
		// default backend equivalent
		if len(endps) == 0 {
			glog.Warningf("service %v/%v does not have any active endpoints for port %v and protocol %v", svcNs, svcName, svcPort, proto)
			continue
		}

		svcs = append(svcs, ingress.L4Service{
			Port: externalPort,
			Backend: ingress.L4Backend{
				Name:      svcName,
				Namespace: svcNs,
				Port:      intstr.FromString(svcPort),
				Protocol:  proto,
			},
			Endpoints: endps,
		})
	}

	return svcs
}

// getDefaultUpstream returns an upstream associated with the
// default backend service. In case of error retrieving information
// configure the upstream to return http code 503.
func (ic *GenericController) getDefaultUpstream() *ingress.Backend {
	upstream := &ingress.Backend{
		Name: defUpstreamName,
	}
	svcKey := ic.cfg.DefaultService
	svcObj, svcExists, err := ic.svcLister.Indexer.GetByKey(svcKey)
	if err != nil {
		glog.Warningf("unexpected error searching the default backend %v: %v", ic.cfg.DefaultService, err)
		upstream.Endpoints = append(upstream.Endpoints, newDefaultServer())
		return upstream
	}

	if !svcExists {
		glog.Warningf("service %v does not exists", svcKey)
		upstream.Endpoints = append(upstream.Endpoints, newDefaultServer())
		return upstream
	}

	svc := svcObj.(*api.Service)
	endps := ic.getEndpoints(svc, svc.Spec.Ports[0].TargetPort, api.ProtocolTCP, &healthcheck.Upstream{})
	if len(endps) == 0 {
		glog.Warningf("service %v does not have any active endpoints", svcKey)
		endps = []ingress.Endpoint{newDefaultServer()}
	}

	upstream.Endpoints = append(upstream.Endpoints, endps...)
	return upstream
}

type ingressByRevision []interface{}

func (c ingressByRevision) Len() int      { return len(c) }
func (c ingressByRevision) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
func (c ingressByRevision) Less(i, j int) bool {
	ir := c[i].(*extensions.Ingress).ResourceVersion
	jr := c[j].(*extensions.Ingress).ResourceVersion
	return ir < jr
}

// getBackendServers returns a list of Upstream and Server to be used by the backend
// An upstream can be used in multiple servers if the namespace, service name and port are the same
func (ic *GenericController) getBackendServers() ([]*ingress.Backend, []*ingress.Server) {
	ings := ic.ingLister.Store.List()
	sort.Sort(ingressByRevision(ings))

	upstreams := ic.createUpstreams(ings)
	servers := ic.createServers(ings, upstreams)

	for _, ingIf := range ings {
		ing := ingIf.(*extensions.Ingress)

		if !IsValidClass(ing, ic.cfg) {
			continue
		}

		anns := ic.annotations.Extract(ing)

		for _, rule := range ing.Spec.Rules {
			host := rule.Host
			if host == "" {
				host = defServerName
			}
			server := servers[host]
			if server == nil {
				server = servers[defServerName]
			}

			if rule.HTTP == nil &&
				host != defServerName {
				glog.V(3).Infof("ingress rule %v/%v does not contains HTTP rules. using default backend", ing.Namespace, ing.Name)
				continue
			}

			for _, path := range rule.HTTP.Paths {
				upsName := fmt.Sprintf("%v-%v-%v",
					ing.GetNamespace(),
					path.Backend.ServiceName,
					path.Backend.ServicePort.String())

				ups := upstreams[upsName]

				// if there's no path defined we assume /
				nginxPath := rootLocation
				if path.Path != "" {
					nginxPath = path.Path
				}

				addLoc := true
				for _, loc := range server.Locations {
					if loc.Path == nginxPath {
						addLoc = false

						if !loc.IsDefBackend {
							glog.V(3).Infof("avoiding replacement of ingress rule %v/%v location %v upstream %v (%v)", ing.Namespace, ing.Name, loc.Path, ups.Name, loc.Backend)
							break
						}

						glog.V(3).Infof("replacing ingress rule %v/%v location %v upstream %v (%v)", ing.Namespace, ing.Name, loc.Path, ups.Name, loc.Backend)
						loc.Backend = ups.Name
						loc.IsDefBackend = false
						loc.Backend = ups.Name
						mergeLocationAnnotations(loc, anns)
						break
					}
				}
				// is a new location
				if addLoc {
					glog.V(3).Infof("adding location %v in ingress rule %v/%v upstream %v", nginxPath, ing.Namespace, ing.Name, ups.Name)
					loc := &ingress.Location{
						Path:         nginxPath,
						Backend:      ups.Name,
						IsDefBackend: false,
					}
					mergeLocationAnnotations(loc, anns)
					server.Locations = append(server.Locations, loc)
				}
			}
		}
	}

	// TODO: find a way to make this more readable
	// The structs must be ordered to always generate the same file
	// if the content does not change.
	aUpstreams := make([]*ingress.Backend, 0, len(upstreams))
	for _, value := range upstreams {
		if len(value.Endpoints) == 0 {
			glog.V(3).Infof("upstream %v does not have any active endpoints. Using default backend", value.Name)
			value.Endpoints = append(value.Endpoints, newDefaultServer())
		}
		aUpstreams = append(aUpstreams, value)
	}
	sort.Sort(ingress.BackendByNameServers(aUpstreams))

	aServers := make([]*ingress.Server, 0, len(servers))
	for _, value := range servers {
		sort.Sort(ingress.LocationByPath(value.Locations))
		aServers = append(aServers, value)
	}
	sort.Sort(ingress.ServerByName(aServers))

	return aUpstreams, aServers
}

// GetAuthCertificate ...
func (ic GenericController) GetAuthCertificate(secretName string) (*resolver.AuthSSLCert, error) {
	key, err := ic.GetSecret(secretName)
	if err != nil {
		return &resolver.AuthSSLCert{}, fmt.Errorf("unexpected error: %v", err)
	}
	if key != nil {
		ic.secretQueue.Enqueue(key)
	}

	bc, exists := ic.sslCertTracker.Get(secretName)
	if !exists {
		return &resolver.AuthSSLCert{}, fmt.Errorf("secret %v does not exists", secretName)
	}
	cert := bc.(*ingress.SSLCert)
	return &resolver.AuthSSLCert{
		Secret:     secretName,
		CAFileName: cert.CAFileName,
		PemSHA:     cert.PemSHA,
	}, nil
}

// createUpstreams creates the NGINX upstreams for each service referenced in
// Ingress rules. The servers inside the upstream are endpoints.
func (ic *GenericController) createUpstreams(data []interface{}) map[string]*ingress.Backend {
	upstreams := make(map[string]*ingress.Backend)
	upstreams[defUpstreamName] = ic.getDefaultUpstream()

	for _, ingIf := range data {
		ing := ingIf.(*extensions.Ingress)

		if !IsValidClass(ing, ic.cfg) {
			continue
		}

		secUpstream := ic.annotations.SecureUpstream(ing)
		hz := ic.annotations.HealthCheck(ing)
		affinity := ic.annotations.SessionAffinity(ing)

		var defBackend string
		if ing.Spec.Backend != nil {
			defBackend = fmt.Sprintf("%v-%v-%v",
				ing.GetNamespace(),
				ing.Spec.Backend.ServiceName,
				ing.Spec.Backend.ServicePort.String())

			glog.V(3).Infof("creating upstream %v", defBackend)
			upstreams[defBackend] = newUpstream(defBackend)

			svcKey := fmt.Sprintf("%v/%v", ing.GetNamespace(), ing.Spec.Backend.ServiceName)
			endps, err := ic.serviceEndpoints(svcKey, ing.Spec.Backend.ServicePort.String(), hz)
			upstreams[defBackend].Endpoints = append(upstreams[defBackend].Endpoints, endps...)
			if err != nil {
				glog.Warningf("error creating upstream %v: %v", defBackend, err)
			}
		}

		for _, rule := range ing.Spec.Rules {
			if rule.HTTP == nil {
				continue
			}

			for _, path := range rule.HTTP.Paths {
				name := fmt.Sprintf("%v-%v-%v",
					ing.GetNamespace(),
					path.Backend.ServiceName,
					path.Backend.ServicePort.String())

				if _, ok := upstreams[name]; ok {
					continue
				}

				glog.V(3).Infof("creating upstream %v", name)
				upstreams[name] = newUpstream(name)
				if !upstreams[name].Secure {
					upstreams[name].Secure = secUpstream
				}
				if upstreams[name].SessionAffinity.AffinityType == "" {
					upstreams[name].SessionAffinity.AffinityType = affinity.AffinityType
					if affinity.AffinityType == "cookie" {
						upstreams[name].SessionAffinity.CookieSessionAffinity.Name = affinity.CookieConfig.Name
						upstreams[name].SessionAffinity.CookieSessionAffinity.Hash = affinity.CookieConfig.Hash
					}
				}

				svcKey := fmt.Sprintf("%v/%v", ing.GetNamespace(), path.Backend.ServiceName)
				endp, err := ic.serviceEndpoints(svcKey, path.Backend.ServicePort.String(), hz)
				if err != nil {
					glog.Warningf("error obtaining service endpoints: %v", err)
					continue
				}
				upstreams[name].Endpoints = endp
			}
		}
	}

	return upstreams
}

// serviceEndpoints returns the upstream servers (endpoints) associated
// to a service.
func (ic *GenericController) serviceEndpoints(svcKey, backendPort string,
	hz *healthcheck.Upstream) ([]ingress.Endpoint, error) {
	svcObj, svcExists, err := ic.svcLister.Indexer.GetByKey(svcKey)

	var upstreams []ingress.Endpoint
	if err != nil {
		return upstreams, fmt.Errorf("error getting service %v from the cache: %v", svcKey, err)
	}

	if !svcExists {
		err = fmt.Errorf("service %v does not exists", svcKey)
		return upstreams, err
	}

	svc := svcObj.(*api.Service)
	glog.V(3).Infof("obtaining port information for service %v", svcKey)
	for _, servicePort := range svc.Spec.Ports {
		// targetPort could be a string, use the name or the port (int)
		if strconv.Itoa(int(servicePort.Port)) == backendPort ||
			servicePort.TargetPort.String() == backendPort ||
			servicePort.Name == backendPort {

			endps := ic.getEndpoints(svc, servicePort.TargetPort, api.ProtocolTCP, hz)
			if len(endps) == 0 {
				glog.Warningf("service %v does not have any active endpoints", svcKey)
			}

			sort.Sort(ingress.EndpointByAddrPort(endps))
			upstreams = append(upstreams, endps...)
			break
		}
	}

	return upstreams, nil
}

// createServers initializes a map that contains information about the list of
// FDQN referenced by ingress rules and the common name field in the referenced
// SSL certificates. Each server is configured with location / using a default
// backend specified by the user or the one inside the ingress spec.
func (ic *GenericController) createServers(data []interface{},
	upstreams map[string]*ingress.Backend) map[string]*ingress.Server {
	servers := make(map[string]*ingress.Server)

	bdef := ic.GetDefaultBackend()
	ngxProxy := proxy.Configuration{
		BodySize:       bdef.ProxyBodySize,
		ConnectTimeout: bdef.ProxyConnectTimeout,
		SendTimeout:    bdef.ProxySendTimeout,
		ReadTimeout:    bdef.ProxyReadTimeout,
		BufferSize:     bdef.ProxyBufferSize,
		CookieDomain:   bdef.ProxyCookieDomain,
		CookiePath:     bdef.ProxyCookiePath,
	}

	// This adds the Default Certificate to Default Backend and also for vhosts missing the secret
	var defaultPemFileName, defaultPemSHA string
	defaultCertificate, err := ic.getPemCertificate(ic.cfg.DefaultSSLCertificate)
	// If no default Certificate was supplied, tries to generate a new dumb one
	if err != nil {
		var cert *ingress.SSLCert

		fakeCertificate := "default-fake-certificate"
		fakeCertificatePath := fmt.Sprintf("%v/%v.pem", ingress.DefaultSSLDirectory, fakeCertificate)

		// Only generates a new certificate if it doesn't exists physically
		_, err := os.Stat(fakeCertificatePath)
		if err != nil {
			defCert, defKey := ssl.GetFakeSSLCert()
			cert, err = ssl.AddOrUpdateCertAndKey(fakeCertificate, defCert, defKey, []byte{})
			if err != nil {
				glog.Fatalf("Error generating self signed certificate: %v", err)
			}
			defaultPemFileName = cert.PemFileName
			defaultPemSHA = cert.PemSHA
		} else {
			defaultPemFileName = fakeCertificatePath
			defaultPemSHA = ssl.PemSHA1(fakeCertificatePath)
		}
	} else {
		defaultPemFileName = defaultCertificate.PemFileName
		defaultPemSHA = defaultCertificate.PemSHA
	}

	// initialize the default server
	servers[defServerName] = &ingress.Server{
		Hostname:       defServerName,
		SSLCertificate: defaultPemFileName,
		SSLPemChecksum: defaultPemSHA,
		Locations: []*ingress.Location{
			{
				Path:         rootLocation,
				IsDefBackend: true,
				Backend:      ic.getDefaultUpstream().Name,
				Proxy:        ngxProxy,
			},
		}}

	// initialize all the servers
	for _, ingIf := range data {
		ing := ingIf.(*extensions.Ingress)
		if !IsValidClass(ing, ic.cfg) {
			continue
		}

		// check if ssl passthrough is configured
		sslpt := ic.annotations.SSLPassthrough(ing)
		dun := ic.getDefaultUpstream().Name
		if ing.Spec.Backend != nil {
			// replace default backend
			defUpstream := fmt.Sprintf("%v-%v-%v", ing.GetNamespace(), ing.Spec.Backend.ServiceName, ing.Spec.Backend.ServicePort.String())
			if backendUpstream, ok := upstreams[defUpstream]; ok {
				dun = backendUpstream.Name
			}
		}

		for _, rule := range ing.Spec.Rules {
			host := rule.Host
			if host == "" {
				host = defServerName
			}
			if _, ok := servers[host]; ok {
				// server already configured
				continue
			}
			servers[host] = &ingress.Server{
				Hostname: host,
				Locations: []*ingress.Location{
					{
						Path:         rootLocation,
						IsDefBackend: true,
						Backend:      dun,
						Proxy:        ngxProxy,
					},
				}, SSLPassthrough: sslpt}
		}
	}

	// configure default location and SSL
	for _, ingIf := range data {
		ing := ingIf.(*extensions.Ingress)
		if !IsValidClass(ing, ic.cfg) {
			continue
		}

		for _, rule := range ing.Spec.Rules {
			host := rule.Host
			if host == "" {
				host = defServerName
			}

			// only add a certificate if the server does not have one previously configured
			// TODO: TLS without secret?
			if len(ing.Spec.TLS) > 0 && servers[host].SSLCertificate == "" {
				tlsSecretName := ""
				for _, tls := range ing.Spec.TLS {
					for _, tlsHost := range tls.Hosts {
						if tlsHost == host {
							tlsSecretName = tls.SecretName
							break
						}
					}
				}

				key := fmt.Sprintf("%v/%v", ing.Namespace, tlsSecretName)
				bc, exists := ic.sslCertTracker.Get(key)
				if exists {
					cert := bc.(*ingress.SSLCert)
					if isHostValid(host, cert) {
						servers[host].SSLCertificate = cert.PemFileName
						servers[host].SSLPemChecksum = cert.PemSHA
					}
				}
			}
		}
	}

	return servers
}

// getEndpoints returns a list of <endpoint ip>:<port> for a given service/target port combination.
func (ic *GenericController) getEndpoints(
	s *api.Service,
	servicePort intstr.IntOrString,
	proto api.Protocol,
	hz *healthcheck.Upstream) []ingress.Endpoint {
	glog.V(3).Infof("getting endpoints for service %v/%v and port %v", s.Namespace, s.Name, servicePort.String())
	ep, err := ic.endpLister.GetServiceEndpoints(s)
	if err != nil {
		glog.Warningf("unexpected error obtaining service endpoints: %v", err)
		return []ingress.Endpoint{}
	}

	upsServers := []ingress.Endpoint{}

	for _, ss := range ep.Subsets {
		for _, epPort := range ss.Ports {

			if !reflect.DeepEqual(epPort.Protocol, proto) {
				continue
			}

			var targetPort int32

			switch servicePort.Type {
			case intstr.Int:
				if int(epPort.Port) == servicePort.IntValue() {
					targetPort = epPort.Port
				}
			case intstr.String:
				port, err := service.GetPortMapping(servicePort.StrVal, s)
				if err == nil {
					targetPort = port
					break
				}

				glog.Warningf("error mapping service port: %v", err)
				err = ic.checkSvcForUpdate(s)
				if err != nil {
					glog.Warningf("error mapping service ports: %v", err)
					continue
				}

				port, err = service.GetPortMapping(servicePort.StrVal, s)
				if err == nil {
					targetPort = port
				}
			}

			// check for invalid port value
			if targetPort <= 0 {
				continue
			}

			for _, epAddress := range ss.Addresses {
				ups := ingress.Endpoint{
					Address:     epAddress.IP,
					Port:        fmt.Sprintf("%v", targetPort),
					MaxFails:    hz.MaxFails,
					FailTimeout: hz.FailTimeout,
				}
				upsServers = append(upsServers, ups)
			}
		}
	}

	glog.V(3).Infof("endpoints found: %v", upsServers)
	return upsServers
}

// Stop stops the loadbalancer controller.
func (ic GenericController) Stop() error {
	ic.stopLock.Lock()
	defer ic.stopLock.Unlock()

	// Only try draining the workqueue if we haven't already.
	if !ic.syncQueue.IsShuttingDown() {
		glog.Infof("shutting down controller queues")
		close(ic.stopCh)
		go ic.syncQueue.Shutdown()
		go ic.secretQueue.Shutdown()
		if ic.syncStatus != nil {
			ic.syncStatus.Shutdown()
		}
		return nil
	}

	return fmt.Errorf("shutdown already in progress")
}

// Start starts the Ingress controller.
func (ic GenericController) Start() {
	glog.Infof("starting Ingress controller")

	go ic.ingController.Run(ic.stopCh)
	go ic.endpController.Run(ic.stopCh)
	go ic.svcController.Run(ic.stopCh)
	go ic.nodeController.Run(ic.stopCh)
	go ic.secrController.Run(ic.stopCh)
	go ic.mapController.Run(ic.stopCh)

	go ic.secretQueue.Run(5*time.Second, ic.stopCh)
	go ic.syncQueue.Run(5*time.Second, ic.stopCh)

	if ic.syncStatus != nil {
		go ic.syncStatus.Run(ic.stopCh)
	}

	<-ic.stopCh
}