A really crappy SNI implementation

I've developed a poor and embarrassing form of SNI support into the
ingress controller based on the existing TCP "support". This probably
only works with nginx.

I don't think anyone should attempt to merge this code anywhere,
however, functionally this is the behavior that I wanted.

controllers/nginx/Makefile

@@ -26,7 +26,7 @@ ARCH ?= $(shell go env GOARCH)
 GOARCH = ${ARCH}
 DUMB_ARCH = ${ARCH}
 
-ALL_ARCH = amd64 arm arm64 ppc64le
+ALL_ARCH ?= amd64 arm arm64 ppc64le
 
 QEMUVERSION=v2.9.1
 

controllers/nginx/pkg/cmd/controller/nginx.go

@@ -649,6 +649,7 @@ func (n *NGINXController) OnUpdate(ingressCfg ingress.Configuration) error {
 		PassthroughBackends:     ingressCfg.PassthroughBackends,
 		Servers:                 ingressCfg.Servers,
 		TCPBackends:             ingressCfg.TCPEndpoints,
+		SNIBackends:             ingressCfg.SNIEndpoints,
 		UDPBackends:             ingressCfg.UDPEndpoints,
 		HealthzURI:              ngxHealthPath,
 		CustomErrors:            len(cfg.CustomHTTPErrors) > 0,

controllers/nginx/pkg/config/config.go

@@ -478,6 +478,7 @@ type TemplateConfig struct {
 	PassthroughBackends     []*ingress.SSLPassthroughBackend
 	Servers                 []*ingress.Server
 	TCPBackends             []ingress.L4Service
+	SNIBackends             []ingress.L4Service
 	UDPBackends             []ingress.L4Service
 	HealthzURI              string
 	CustomErrors            bool

core/pkg/ingress/controller/controller.go

@@ -136,6 +136,8 @@ type Configuration struct {
 	// optional
 	TCPConfigMapName string
 	// optional
+	SNIConfigMapName string
+	// optional
 	UDPConfigMapName      string
 	DefaultSSLCertificate string
 	DefaultHealthzURL     string
@@ -293,7 +295,7 @@ func newIngressController(config *Configuration) *GenericController {
 					ic.forceReload = true
 				}
 				// updates to configuration configmaps can trigger an update
-				if mapKey == ic.cfg.ConfigMapName || mapKey == ic.cfg.TCPConfigMapName || mapKey == ic.cfg.UDPConfigMapName {
+				if mapKey == ic.cfg.ConfigMapName || mapKey == ic.cfg.TCPConfigMapName || mapKey == ic.cfg.SNIConfigMapName || mapKey == ic.cfg.UDPConfigMapName {
 					ic.recorder.Eventf(upCmap, api.EventTypeNormal, "UPDATE", fmt.Sprintf("ConfigMap %v", mapKey))
 					ic.syncQueue.Enqueue(cur)
 				}
@@ -465,6 +467,7 @@ func (ic *GenericController) syncIngress(key interface{}) error {
 		Backends:            upstreams,
 		Servers:             servers,
 		TCPEndpoints:        ic.getStreamServices(ic.cfg.TCPConfigMapName, api.ProtocolTCP),
+		SNIEndpoints:        ic.getStreamServices(ic.cfg.SNIConfigMapName, api.ProtocolSNI),
 		UDPEndpoints:        ic.getStreamServices(ic.cfg.UDPConfigMapName, api.ProtocolUDP),
 		PassthroughBackends: passUpstreams,
 	}
@@ -513,21 +516,44 @@ func (ic *GenericController) getStreamServices(configmapName string, proto api.P
 	}
 
 	var svcs []ingress.L4Service
-	// k -> port to expose
-	// v -> <namespace>/<service name>:<port from service to be used>
+	// k -> port to expose for TCP and UDP, hostname for SNI
+	// v -> <namespace>/<service name>:<port from service to be used> for TCP and UDP
+	// v -> <namespace>/<service name>:<port from service to be used>!<service-upstream true/false> for SNI
 	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
+		glog.V(3).Infof("Evaluating: %v => %v", k, v)
+		var externalPort int
+		var hostname string
+		if proto == api.ProtocolSNI {
+			hostname = k
+			externalPort = 8443
+		} else {
+			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
+		// this port is 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
 		}
 
+		serviceUpstream := false
+		if proto == api.ProtocolSNI {
+			glog.V(3).Infof("proto is sni, looking for serviceUpstream info")
+			tokens := strings.Split(v, "!")
+			if len(tokens) == 2 {
+				glog.V(3).Infof("Found the bang")
+				if tokens[1] == "true" {
+					glog.V(3).Infof("serviceUpstream is requested")
+					serviceUpstream = true
+				}
+				glog.V(3).Infof("setting v to %v", tokens[0])
+				v = tokens[0]
+			}
+		}
 		nsSvcPort := strings.Split(v, ":")
 		if len(nsSvcPort) < 2 {
 			glog.Warningf("invalid format (namespace/name:port:[PROXY]) '%v'", k)
@@ -538,8 +564,8 @@ func (ic *GenericController) getStreamServices(configmapName string, proto api.P
 		svcPort := nsSvcPort[1]
 		useProxyProtocol := false
 
-		// Proxy protocol is possible if the service is TCP
-		if len(nsSvcPort) == 3 && proto == api.ProtocolTCP {
+		// Proxy protocol is possible if the service is TCP or SNI
+		if len(nsSvcPort) == 3 && (proto == api.ProtocolTCP || proto == api.ProtocolSNI) {
 			if strings.ToUpper(nsSvcPort[2]) == "PROXY" {
 				useProxyProtocol = true
 			}
@@ -565,25 +591,63 @@ func (ic *GenericController) getStreamServices(configmapName string, proto api.P
 		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 {
-					if sp.Protocol == proto {
-						endps = ic.getEndpoints(svc, &sp, proto, &healthcheck.Upstream{})
-						break
+		// Add the service cluster endpoint as the upstream instead of individual endpoints
+		// if the serviceUpstream annotation is enabled
+		if serviceUpstream {
+			svcKey := fmt.Sprintf("%v/%v", svcNs, svcName)
+			svcObj, svcExists, err := ic.svcLister.Store.GetByKey(svcKey)
+
+			if err != nil {
+				// XXX This is stupid. If the kube API server is down or
+				// something we'll start tearing apart our perfectly good
+				// configuration. The better option here is to noop.
+				glog.Warningf("Unable to query for info about service %v, skipping", svcKey)
+				continue
+			}
+
+			if !svcExists {
+				glog.Warningf("Service %v was not found, ignoring.", svcKey)
+				continue
+			}
+
+			svc := svcObj.(*api.Service)
+			if svc.Spec.ClusterIP == "" {
+				glog.Warningf("No ClusterIP found for service %s", svcKey)
+				continue
+			}
+			endps = []ingress.Endpoint{ingress.Endpoint{
+				Address: svc.Spec.ClusterIP,
+				Port:    svcPort,
+			}}
+		} else {
+			targetPort, err := strconv.Atoi(svcPort)
+			// We're going to go searching through service endpoints for the port
+			// and proto we're trying to forward to. SNI, however, is not a valid
+			// protocol for services. We continue our hack here by mapping SNI to
+			// TCP for these purposes.
+			searchProto := proto
+			if searchProto == api.ProtocolSNI {
+				searchProto = api.ProtocolTCP
+			}
+			if err != nil {
+				glog.V(3).Infof("searching service %v/%v endpoints using the name '%v' and proto '%v'", svcNs, svcName, svcPort, searchProto)
+				for _, sp := range svc.Spec.Ports {
+					if sp.Name == svcPort {
+						if sp.Protocol == searchProto {
+							endps = ic.getEndpoints(svc, &sp, searchProto, &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) {
-					if sp.Protocol == proto {
-						endps = ic.getEndpoints(svc, &sp, 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' and proto '%v'", svcNs, svcName, targetPort, searchProto)
+				for _, sp := range svc.Spec.Ports {
+					if sp.Port == int32(targetPort) {
+						if sp.Protocol == searchProto {
+							endps = ic.getEndpoints(svc, &sp, searchProto, &healthcheck.Upstream{})
+							break
+						}
 					}
 				}
 			}
@@ -604,6 +668,7 @@ func (ic *GenericController) getStreamServices(configmapName string, proto api.P
 				Port:             intstr.FromString(svcPort),
 				Protocol:         proto,
 				UseProxyProtocol: useProxyProtocol,
+				ServerName:       hostname,
 			},
 			Endpoints: endps,
 		})

core/pkg/ingress/controller/launch.go

@@ -60,6 +60,15 @@ func NewIngressController(backend ingress.Controller) *GenericController {
 		number of the name of the port.
 		The ports 80 and 443 are not allowed as external ports. This ports are reserved for the backend`)
 
+		sniConfigMapName = flags.String("sni-services-configmap", "",
+			`Name of the ConfigMap that contains the definition of the SNI services to expose.
+		The key in the map indicates the SNI name to look for in a TLS client
+		hello and the external port to be used. The value is the name of the
+		service with the format namespace/serviceName and the port of the
+		service could be a number of the name of the port. The ports 80 and 443
+		are not allowed as external ports. This ports are reserved for the
+		backend`)
+
 		udpConfigMapName = flags.String("udp-services-configmap", "",
 			`Name of the ConfigMap that contains the definition of the UDP services to expose.
 		The key in the map indicates the external port to be used. The value is the name of the
@@ -180,6 +189,7 @@ func NewIngressController(backend ingress.Controller) *GenericController {
 		Namespace:               *watchNamespace,
 		ConfigMapName:           *configMap,
 		TCPConfigMapName:        *tcpConfigMapName,
+		SNIConfigMapName:        *sniConfigMapName,
 		UDPConfigMapName:        *udpConfigMapName,
 		DefaultSSLCertificate:   *defSSLCertificate,
 		DefaultHealthzURL:       *defHealthzURL,

core/pkg/ingress/types.go

@@ -140,6 +140,9 @@ type Configuration struct {
 	// TCPEndpoints contain endpoints for tcp streams handled by this backend
 	// +optional
 	TCPEndpoints []L4Service `json:"tcpEndpoints,omitempty"`
+	// SNIEndpoints contain endpoints for SNI streams handled by this backend
+	// +optional
+	SNIEndpoints []L4Service `json:"sniEndpoints,omitempty"`
 	// UDPEndpoints contain endpoints for udp streams handled by this backend
 	// +optional
 	UDPEndpoints []L4Service `json:"udpEndpoints,omitempty"`
@@ -349,7 +352,7 @@ type L4Service struct {
 	// Backend of the service
 	Backend L4Backend `json:"backend"`
 	// Endpoints active endpoints of the service
-	Endpoints []Endpoint `json:"endpoins,omitEmpty"`
+	Endpoints []Endpoint `json:"endpoints,omitEmpty"`
 }
 
 // L4Backend describes the kubernetes service behind L4 Ingress service
@@ -360,4 +363,6 @@ type L4Backend struct {
 	Protocol  api.Protocol       `json:"protocol"`
 	// +optional
 	UseProxyProtocol bool `json:"useProxyProtocol"`
+	// +optional This is the name we'll route SNI requests on when proto is SNI
+	ServerName string `json:"servername"`
 }

vendor/k8s.io/api/core/v1/types.go

@@ -847,6 +847,8 @@ type Protocol string
 const (
 	// ProtocolTCP is the TCP protocol.
 	ProtocolTCP Protocol = "TCP"
+	// ProtocolSNI is the TCP protocol where we will inspect the TLS client hello for name information.
+	ProtocolSNI Protocol = "SNI"
 	// ProtocolUDP is the UDP protocol.
 	ProtocolUDP Protocol = "UDP"
 )