mw/kubernetes: remove kService and kPod

Remove the intermediate step of gathering everyhing in a kPod and
kService and extracting the msg.Service from there. Now findPods and
findServices return []msg.Service.

This cuts down on the code and also removed the double looping of
finding the data we need, so it should be faster.

middleware/kubernetes/kubernetes.go

@@ -75,27 +75,6 @@ const (
 	DNSSchemaVersion = "1.0.1"
 )
 
-type endpoint struct {
-	addr api.EndpointAddress
-	port api.EndpointPort
-}
-
-// kService is a service as retrieved via the k8s API.
-type kService struct {
-	name      string
-	namespace string
-	addr      string
-	ports     []api.ServicePort
-	endpoints []endpoint
-}
-
-// kPod is a pod as retrieved via the k8s API.
-type kPod struct {
-	name      string
-	namespace string
-	addr      string
-}
-
 var (
 	errNoItems        = errors.New("no items found")
 	errNsNotExposed   = errors.New("namespace is not exposed")
@@ -301,7 +280,7 @@ func (k *Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
 
 // Entries looks up services in kubernetes.
 func (k *Kubernetes) Entries(state request.Request) ([]msg.Service, error) {
-	r, e := k.parseRequest(state)
+	r, e := parseRequest(state)
 	if e != nil {
 		return nil, e
 	}
@@ -310,16 +289,13 @@ func (k *Kubernetes) Entries(state request.Request) ([]msg.Service, error) {
 		return nil, errNsNotExposed
 	}
 
-	services, pods, err := k.get(r)
-	if err != nil {
-		return nil, err
-	}
-	if len(services) == 0 && len(pods) == 0 {
-		return nil, errNoItems
+	if r.podOrSvc == Pod {
+		pods, err := k.findPods(r, state.Zone)
+		return pods, err
 	}
 
-	records := k.getRecordsForK8sItems(services, pods, state.Zone)
-	return records, nil
+	services, err := k.findServices(r, state.Zone)
+	return services, err
 }
 
 func endpointHostname(addr api.EndpointAddress) string {
@@ -335,51 +311,18 @@ func endpointHostname(addr api.EndpointAddress) string {
 	return ""
 }
 
-func (k *Kubernetes) getRecordsForK8sItems(services []kService, pods []kPod, zone string) (records []msg.Service) {
-	zonePath := msg.Path(zone, "coredns")
-
-	for _, svc := range services {
-		if svc.addr == api.ClusterIPNone || len(svc.endpoints) > 0 {
-			// This is a headless service or endpoints are present, create records for each endpoint
-			for _, ep := range svc.endpoints {
-				s := msg.Service{Host: ep.addr.IP, Port: int(ep.port.Port)}
-				s.Key = strings.Join([]string{zonePath, Svc, svc.namespace, svc.name, endpointHostname(ep.addr)}, "/")
-
-				records = append(records, s)
-			}
-			continue
-		}
-
-		// Create records for each exposed port...
-		for _, p := range svc.ports {
-			s := msg.Service{Host: svc.addr, Port: int(p.Port)}
-			s.Key = strings.Join([]string{zonePath, Svc, svc.namespace, svc.name}, "/")
-
-			records = append(records, s)
-		}
-		// If the addr is not an IP (i.e. an external service), add the record ...
-		s := msg.Service{Key: strings.Join([]string{zonePath, Svc, svc.namespace, svc.name}, "/"), Host: svc.addr}
-		if t, _ := s.HostType(); t == dns.TypeCNAME {
-			s.Key = strings.Join([]string{zonePath, Svc, svc.namespace, svc.name}, "/")
-
-			records = append(records, s)
-		}
-	}
-
-	for _, p := range pods {
-		s := msg.Service{Key: strings.Join([]string{zonePath, Pod, p.namespace, p.name}, "/"), Host: p.addr}
-		records = append(records, s)
-	}
-
-	return records
-}
-
-func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error) {
+// findPods returns the pods matching r from the cache.
+func (k *Kubernetes) findPods(r recordRequest, zone string) (pods []msg.Service, err error) {
 	if k.PodMode == PodModeDisabled {
-		return pods, errPodsDisabled
+		return nil, errPodsDisabled
 	}
 
-	var ip string
+	namespace := r.namespace
+	podname := r.service
+	zonePath := msg.Path(zone, "coredns")
+	ip := ""
+	err = errNoItems
+
 	if strings.Count(podname, "-") == 3 && !strings.Contains(podname, "--") {
 		ip = strings.Replace(podname, "-", ".", -1)
 	} else {
@@ -387,9 +330,7 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error
 	}
 
 	if k.PodMode == PodModeInsecure {
-		s := kPod{name: podname, namespace: namespace, addr: ip}
-		pods = append(pods, s)
-		return pods, nil
+		return []msg.Service{{Key: strings.Join([]string{zonePath, Pod, namespace, podname}, "/"), Host: ip}}, nil
 	}
 
 	// PodModeVerified
@@ -406,29 +347,20 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error
 		}
 		// check for matching ip and namespace
 		if ip == p.Status.PodIP && match(namespace, p.Namespace) {
-			s := kPod{name: podname, namespace: namespace, addr: ip}
+			s := msg.Service{Key: strings.Join([]string{zonePath, Pod, namespace, podname}, "/"), Host: ip}
 			pods = append(pods, s)
-			return pods, nil
+
+			err = nil
 		}
 	}
-	return pods, nil
+	return pods, err
 }
 
-// get retrieves matching data from the cache.
-func (k *Kubernetes) get(r recordRequest) (services []kService, pods []kPod, err error) {
-	switch r.podOrSvc {
-	case Pod:
-		pods, err = k.findPods(r.namespace, r.service)
-		return nil, pods, err
-	default:
-		services, err = k.findServices(r)
-		return services, nil, err
-	}
-}
-
-func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
+// findServices returns the services matching r from the cache.
+func (k *Kubernetes) findServices(r recordRequest, zone string) (services []msg.Service, err error) {
 	serviceList := k.APIConn.ServiceList()
-	var resultItems []kService
+	zonePath := msg.Path(zone, "coredns")
+	err = errNoItems // Set to errNoItems to signal really nothing found, gets reset when name is matched.
 
 	for _, svc := range serviceList {
 		if !(match(r.namespace, svc.Namespace) && match(r.service, svc.Name)) {
@@ -440,17 +372,17 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
 		if wildcard(r.namespace) && !k.namespaceExposed(svc.Namespace) {
 			continue
 		}
-		s := kService{name: svc.Name, namespace: svc.Namespace}
 
 		// Endpoint query or headless service
 		if svc.Spec.ClusterIP == api.ClusterIPNone || r.endpoint != "" {
-			s.addr = svc.Spec.ClusterIP
 			endpointsList := k.APIConn.EndpointsList()
 			for _, ep := range endpointsList.Items {
 				if ep.ObjectMeta.Name != svc.Name || ep.ObjectMeta.Namespace != svc.Namespace {
 					continue
 				}
 
+				err = nil
+
 				for _, eps := range ep.Subsets {
 					for _, addr := range eps.Addresses {
 
@@ -466,36 +398,45 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
 							if !(match(r.port, p.Name) && match(r.protocol, string(p.Protocol))) {
 								continue
 							}
-							s.endpoints = append(s.endpoints, endpoint{addr: addr, port: p})
+							s := msg.Service{Host: addr.IP, Port: int(p.Port)}
+							s.Key = strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name, endpointHostname(addr)}, "/")
+
+							services = append(services, s)
 						}
 					}
 				}
 			}
-			if len(s.endpoints) > 0 {
-				resultItems = append(resultItems, s)
-			}
 			continue
 		}
 
 		// External service
 		if svc.Spec.ExternalName != "" {
-			s.addr = svc.Spec.ExternalName
-			resultItems = append(resultItems, s)
-			continue
+			s := msg.Service{Key: strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name}, "/"), Host: svc.Spec.ExternalName}
+			if t, _ := s.HostType(); t == dns.TypeCNAME {
+				s.Key = strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name}, "/")
+				services = append(services, s)
+
+				err = nil
+
+				continue
+			}
 		}
 
 		// ClusterIP service
-		s.addr = svc.Spec.ClusterIP
 		for _, p := range svc.Spec.Ports {
 			if !(match(r.port, p.Name) && match(r.protocol, string(p.Protocol))) {
 				continue
 			}
-			s.ports = append(s.ports, p)
-		}
 
-		resultItems = append(resultItems, s)
+			err = nil
+
+			s := msg.Service{Host: svc.Spec.ClusterIP, Port: int(p.Port)}
+			s.Key = strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name}, "/")
+
+			services = append(services, s)
+		}
 	}
-	return resultItems, nil
+	return services, err
 }
 
 // match checks if a and b are equal taking wildcards into account.
@@ -514,39 +455,6 @@ func wildcard(s string) bool {
 	return s == "*" || s == "any"
 }
 
-// serviceRecordForIP gets a service record with a cluster ip matching the ip argument
-// If a service cluster ip does not match, it checks all endpoints
-func (k *Kubernetes) serviceRecordForIP(ip, name string) []msg.Service {
-	// First check services with cluster ips
-	svcList := k.APIConn.ServiceList()
-
-	for _, service := range svcList {
-		if (len(k.Namespaces) > 0) && !k.namespaceExposed(service.Namespace) {
-			continue
-		}
-		if service.Spec.ClusterIP == ip {
-			domain := strings.Join([]string{service.Name, service.Namespace, Svc, k.primaryZone()}, ".")
-			return []msg.Service{{Host: domain}}
-		}
-	}
-	// If no cluster ips match, search endpoints
-	epList := k.APIConn.EndpointsList()
-	for _, ep := range epList.Items {
-		if (len(k.Namespaces) > 0) && !k.namespaceExposed(ep.ObjectMeta.Namespace) {
-			continue
-		}
-		for _, eps := range ep.Subsets {
-			for _, addr := range eps.Addresses {
-				if addr.IP == ip {
-					domain := strings.Join([]string{endpointHostname(addr), ep.ObjectMeta.Name, ep.ObjectMeta.Namespace, Svc, k.primaryZone()}, ".")
-					return []msg.Service{{Host: domain}}
-				}
-			}
-		}
-	}
-	return nil
-}
-
 // namespaceExposed returns true when the namespace is exposed.
 func (k *Kubernetes) namespaceExposed(namespace string) bool {
 	_, ok := k.Namespaces[namespace]