Supporting CaseInsensitive Queries

common/k8sctrl/ctrl.go

@@ -139,13 +139,60 @@ func endpointHostnameIndexFunc(obj interface{}) ([]string, error) {
 
 func (ctrl *KubeController) getEndpointByName(host string, clientIP net.IP) (lep LocalDNSEndpoint) {
 	log.Infof("Index key %+v", host)
-	objs, _ := ctrl.epc.GetIndexer().ByIndex(endpointHostnameIndex, strings.ToLower(host))
-	for _, obj := range objs {
+	endpoints := ctrl.getEndpointsByCaseInsensitiveName(host, clientIP)
+	lep = ctrl.margeLocalDNSEndpoints(host, endpoints)
+	return lep
+}
+
+// The function tries to find all case sensitive variants.  Returns a map where the call is hostname and the value is LocalDNSEndpoint
+func (ctrl *KubeController) getEndpointsByCaseInsensitiveName(host string, clientIP net.IP) (result map[string]LocalDNSEndpoint) {
+
+	// The function extracts LocalDNSEndpoints from *DNSEndpoint. The function is hardwired with a case-sensitive extraction scenario and is only used in a
+	// single location, so it is currently declared inside the calling function.
+	extractLocalEndpoints := func(ep *endpoint.DNSEndpoint, ip net.IP, host string) (result []LocalDNSEndpoint) {
+		result = []LocalDNSEndpoint{}
+		for _, e := range ep.Spec.Endpoints {
+			if strings.EqualFold(e.DNSName, host) {
+				r := LocalDNSEndpoint{}
+				r.DNSName = e.DNSName
+				r.Labels = e.Labels
+				r.TTL = e.RecordTTL
+				r.Targets = e.Targets
+				if e.Labels["strategy"] == "geoip" {
+					targets := r.extractGeo(e, ip)
+					if len(targets) > 0 {
+						r.Targets = targets
+					}
+				}
+				result = append(result, r)
+			}
+		}
+		return result
+	}
+
+	epList := ctrl.epc.GetIndexer().List()
+	result = make(map[string]LocalDNSEndpoint, 0)
+	for _, obj := range epList {
 		ep := obj.(*endpoint.DNSEndpoint)
-		lep = extractLocalEndpoint(ep, clientIP, host)
-		if !lep.isEmpty() {
-			break
+		extracts := extractLocalEndpoints(ep, clientIP, host)
+		for _, extracted := range extracts {
+			if strings.EqualFold(extracted.DNSName, host) {
+				result[extracted.DNSName] = extracted
+				log.Debugf("including DNSEndpoint: %s", extracted.String())
+			}
 		}
 	}
-	return lep
+	return result
+}
+
+func (ctrl *KubeController) margeLocalDNSEndpoints(host string, endpoints map[string]LocalDNSEndpoint) LocalDNSEndpoint {
+	result := LocalDNSEndpoint{
+		DNSName: host,
+	}
+	result.Labels = endpoints[host].Labels
+	result.TTL = endpoints[host].TTL
+	for _, ep := range endpoints {
+		result.Targets = append(result.Targets, ep.Targets...)
+	}
+	return result
 }

common/k8sctrl/ctrl_test.go

@@ -21,6 +21,7 @@ Generated by GoLic, for more details see: https://github.com/AbsaOSS/golic
 import (
 	"context"
 	"reflect"
+	"sort"
 	"testing"
 	"unsafe"
 
@@ -37,6 +38,11 @@ import (
 func TestKubeController(t *testing.T) {
 	const label = "k8gb.absa.oss/dnstype=local"
 	const host = "roundrobin.cloud.example.com"
+	const hOSTCaseInsensitive = "roundrobin-case-insensitive.CLOUD.EXAMPLE.COM"
+	const hostCaseInsensitive = "roundrobin-case-insensitive.cloud.example.com"
+	const embeddedCaseSensitive = "embedded.CLOUD.EXAMPLE.COM"
+	const embeddedCaseInsensitive = "embedded.cloud.example.com"
+	var clientIP = []byte{0x0A, 0x0A, 0x0A, 0x01}
 	defaultEP := &endpoint.DNSEndpoint{
 		Spec: endpoint.DNSEndpointSpec{
 			Endpoints: []*endpoint.Endpoint{
@@ -48,16 +54,77 @@ func TestKubeController(t *testing.T) {
 					Labels:  map[string]string{"strategy": "roundrobin"},
 					Targets: []string{"10.0.0.1", "10.0.0.2"},
 				},
+				{
+					DNSName: hOSTCaseInsensitive,
+					Labels:  map[string]string{"strategy": "roundrobin"},
+					Targets: []string{"1.1.1.1", "1.1.1.2"},
+				},
+				{
+					DNSName: hostCaseInsensitive,
+					Labels:  map[string]string{"strategy": "roundrobin"},
+					Targets: []string{"2.2.2.2"},
+				},
+			},
+		},
+	}
+
+	ep1 := &endpoint.DNSEndpoint{
+		Spec: endpoint.DNSEndpointSpec{
+			Endpoints: []*endpoint.Endpoint{
+				{
+					DNSName: "localtargets-" + hOSTCaseInsensitive,
+				},
+				{
+					DNSName: hOSTCaseInsensitive,
+					Labels:  map[string]string{"strategy": "roundrobin"},
+					Targets: []string{"1.1.1.1", "1.1.1.2"},
+				},
+			},
+		},
+	}
+
+	ep2 := &endpoint.DNSEndpoint{
+		Spec: endpoint.DNSEndpointSpec{
+			Endpoints: []*endpoint.Endpoint{
+				{
+					DNSName: "localtargets-" + hOSTCaseInsensitive,
+				},
+				{
+					DNSName: hostCaseInsensitive,
+					Labels:  map[string]string{"strategy": "roundrobin"},
+					Targets: []string{"2.2.2.2"},
+				},
+			},
+		},
+	}
+
+	epEmbedded := &endpoint.DNSEndpoint{
+		Spec: endpoint.DNSEndpointSpec{
+			Endpoints: []*endpoint.Endpoint{
+				{
+					DNSName: "localtargets-" + embeddedCaseSensitive,
+				},
+				{
+					DNSName: embeddedCaseInsensitive,
+					Labels:  map[string]string{"strategy": "roundrobin"},
+					Targets: []string{"10.10.10.32", "10.10.10.30"},
+				},
+				{
+					DNSName: embeddedCaseSensitive,
+					Labels:  map[string]string{"strategy": "roundrobin"},
+					Targets: []string{"10.10.10.2"},
+				},
 			},
 		},
 	}
+
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
 	mctrl := mocks.NewMockInterface(ctrl)
 	mcache := mocks.NewMockSharedIndexInformer(ctrl)
 	midx := mocks.NewMockIndexer(ctrl)
-	midx.EXPECT().ByIndex(endpointHostnameIndex, host).Return([]interface{}{defaultEP}, nil).Times(1)
-	mcache.EXPECT().GetIndexer().Return(midx)
+	midx.EXPECT().List().Return([]interface{}{defaultEP, ep1, ep2, epEmbedded}).AnyTimes()
+	mcache.EXPECT().GetIndexer().Return(midx).AnyTimes()
 
 	client := getClient(mctrl)
 
@@ -72,11 +139,82 @@ func TestKubeController(t *testing.T) {
 	k8sctrl.epc = mcache
 
 	t.Run("get no-geo endpoint by name", func(t *testing.T) {
-		lep := k8sctrl.getEndpointByName("roundrobin.cloud.example.com", []byte{0x0A, 0x0A, 0x0A, 0x01})
+		lep := k8sctrl.getEndpointByName(host, clientIP)
 		assert.NotNil(t, lep)
 		assert.Equal(t, "roundrobin.cloud.example.com: 0, Targets: [10.0.0.1 10.0.0.2], Labels: map[strategy:roundrobin]", lep.String())
 	})
 
+	t.Run("valid uppercase domain query", func(t *testing.T) {
+		lep := k8sctrl.getEndpointByName(hOSTCaseInsensitive, clientIP)
+		assert.NotNil(t, lep)
+		sort.Strings(lep.Targets)
+		assert.Equal(t, "roundrobin-case-insensitive.CLOUD.EXAMPLE.COM: 0, Targets: [1.1.1.1 1.1.1.2 2.2.2.2], Labels: map[strategy:roundrobin]", lep.String())
+
+		lep = k8sctrl.getEndpointByName(hostCaseInsensitive, clientIP)
+		assert.NotNil(t, lep)
+		sort.Strings(lep.Targets)
+		assert.Equal(t, "roundrobin-case-insensitive.cloud.example.com: 0, Targets: [1.1.1.1 1.1.1.2 2.2.2.2], Labels: map[strategy:roundrobin]", lep.String())
+	})
+
+	t.Run("handle multiple embedded endpoints", func(t *testing.T) {
+		lep := k8sctrl.getEndpointByName(embeddedCaseInsensitive, clientIP)
+		assert.NotNil(t, lep)
+		sort.Strings(lep.Targets)
+		assert.Equal(t, "embedded.cloud.example.com: 0, Targets: [10.10.10.2 10.10.10.30 10.10.10.32], Labels: map[strategy:roundrobin]", lep.String())
+
+		lep = k8sctrl.getEndpointByName(embeddedCaseSensitive, clientIP)
+		assert.NotNil(t, lep)
+		sort.Strings(lep.Targets)
+		assert.Equal(t, "embedded.CLOUD.EXAMPLE.COM: 0, Targets: [10.10.10.2 10.10.10.30 10.10.10.32], Labels: map[strategy:roundrobin]", lep.String())
+	})
+
+	t.Run("handle multiple embedded endpoints but one EP is empty", func(t *testing.T) {
+		epEmbedded.Spec.Endpoints[1].Targets = []string{}
+		lep := k8sctrl.getEndpointByName(embeddedCaseInsensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.cloud.example.com: 0, Targets: [10.10.10.2], Labels: map[strategy:roundrobin]", lep.String())
+
+		lep = k8sctrl.getEndpointByName(embeddedCaseSensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.CLOUD.EXAMPLE.COM: 0, Targets: [10.10.10.2], Labels: map[strategy:roundrobin]", lep.String())
+
+	})
+
+	t.Run("EP has empty targets", func(t *testing.T) {
+		epEmbedded.Spec.Endpoints[1].Targets = []string{}
+		epEmbedded.Spec.Endpoints[2].Targets = []string{}
+		epEmbedded.Spec.Endpoints[0].Targets = []string{}
+		lep := k8sctrl.getEndpointByName(embeddedCaseInsensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.cloud.example.com: 0, Targets: [], Labels: map[strategy:roundrobin]", lep.String())
+
+		lep = k8sctrl.getEndpointByName(embeddedCaseSensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.CLOUD.EXAMPLE.COM: 0, Targets: [], Labels: map[strategy:roundrobin]", lep.String())
+	})
+
+	t.Run("EP has no dns endpoints", func(t *testing.T) {
+		epEmbedded.Spec.Endpoints = []*endpoint.Endpoint{}
+		lep := k8sctrl.getEndpointByName(embeddedCaseInsensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.cloud.example.com: 0, Targets: [], Labels: map[]", lep.String())
+
+		lep = k8sctrl.getEndpointByName(embeddedCaseSensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.CLOUD.EXAMPLE.COM: 0, Targets: [], Labels: map[]", lep.String())
+	})
+
+	t.Run("EP has nil dns endpoints", func(t *testing.T) {
+		epEmbedded.Spec.Endpoints = nil
+		lep := k8sctrl.getEndpointByName(embeddedCaseInsensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.cloud.example.com: 0, Targets: [], Labels: map[]", lep.String())
+
+		lep = k8sctrl.getEndpointByName(embeddedCaseSensitive, clientIP)
+		assert.NotNil(t, lep)
+		assert.Equal(t, "embedded.CLOUD.EXAMPLE.COM: 0, Targets: [], Labels: map[]", lep.String())
+	})
+
 }
 
 func getClient(i rest.Interface) (c *dnsendpoint.ExtDNSClient) {

common/k8sctrl/ep.go

@@ -41,30 +41,6 @@ func (lep LocalDNSEndpoint) String() string {
 	return fmt.Sprintf("%s: %v, Targets: %v, Labels: %v", lep.DNSName, lep.TTL, lep.Targets, lep.Labels)
 }
 
-func extractLocalEndpoint(ep *endpoint.DNSEndpoint, ip net.IP, host string) (result LocalDNSEndpoint) {
-	result = LocalDNSEndpoint{}
-	for _, e := range ep.Spec.Endpoints {
-		if e.DNSName == host {
-			result.DNSName = host
-			result.Labels = e.Labels
-			result.TTL = e.RecordTTL
-			result.Targets = e.Targets
-			if e.Labels["strategy"] == "geoip" {
-				targets := result.extractGeo(e, ip)
-				if len(targets) > 0 {
-					result.Targets = targets
-				}
-			}
-			break
-		}
-	}
-	return result
-}
-
-func (lep LocalDNSEndpoint) isEmpty() bool {
-	return len(lep.Targets) == 0 && (len(lep.Labels) == 0) && (lep.TTL == 0)
-}
-
 func (lep LocalDNSEndpoint) extractGeo(endpoint *endpoint.Endpoint, clientIP net.IP) (result []string) {
 	db, err := maxminddb.Open("geoip.mmdb")
 	if err != nil {