Use resolver module in CoreDNS plugin

Related to submariner-io#214

Signed-off-by: Tom Pantelis <[email protected]>

coredns/gateway/controller.go

@@ -36,20 +36,13 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/client-go/dynamic"
-	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/cache"
 	logf "sigs.k8s.io/controller-runtime/pkg/log"
 )
 
 var logger = log.Logger{Logger: logf.Log.WithName("Gateway")}
 
-type NewClientsetFunc func(c *rest.Config) (dynamic.Interface, error)
-
-// NewClientset is an indirection hook for unit tests to supply fake client sets.
-var NewClientset NewClientsetFunc
-
 type Controller struct {
-	NewClientset     NewClientsetFunc
 	informer         cache.Controller
 	store            cache.Store
 	queue            workqueue.Interface
@@ -61,7 +54,6 @@ type Controller struct {
 
 func NewController() *Controller {
 	controller := &Controller{
-		NewClientset:     getNewClientsetFunc(),
 		queue:            workqueue.New("Gateway Controller"),
 		stopCh:           make(chan struct{}),
 		gatewayAvailable: true,
@@ -77,18 +69,8 @@ func NewController() *Controller {
 	return controller
 }
 
-func getNewClientsetFunc() NewClientsetFunc {
-	if NewClientset != nil {
-		return NewClientset
-	}
-
-	return func(c *rest.Config) (dynamic.Interface, error) {
-		return dynamic.NewForConfig(c)
-	}
-}
-
-func (c *Controller) Start(kubeConfig *rest.Config) error {
-	gwClientset, err := c.getCheckedClientset(kubeConfig)
+func (c *Controller) Start(client dynamic.Interface) error {
+	gwClientset, err := c.getCheckedClientset(client)
 	if apierrors.IsNotFound(err) {
 		logger.Infof("Connectivity component is not installed, disabling Gateway status controller")
 
@@ -100,7 +82,7 @@ func (c *Controller) Start(kubeConfig *rest.Config) error {
 	if err != nil {
 		return err
 	}
-	
+
 	logger.Infof("Starting Gateway status Controller")
 
 	//nolint:wrapcheck // Let the caller wrap these errors.
@@ -211,7 +193,7 @@ func (c *Controller) updateClusterStatusMap(connections []interface{}) {
 }
 
 func (c *Controller) updateLocalClusterIDIfNeeded(clusterID string) {
-	updateNeeded := clusterID != "" && clusterID != c.LocalClusterID()
+	updateNeeded := clusterID != "" && clusterID != c.GetLocalClusterID()
 	if updateNeeded {
 		logger.Infof("Updating the gateway localClusterID %q ", clusterID)
 		c.localClusterID.Store(clusterID)
@@ -264,15 +246,10 @@ func (c *Controller) getClusterStatusMap() map[string]bool {
 	return c.clusterStatusMap.Load().(map[string]bool)
 }
 
-func (c *Controller) getCheckedClientset(kubeConfig *rest.Config) (dynamic.ResourceInterface, error) {
-	clientSet, err := c.NewClientset(kubeConfig)
-	if err != nil {
-		return nil, errors.Wrap(err, "error creating client set")
-	}
-
+func (c *Controller) getCheckedClientset(client dynamic.Interface) (dynamic.ResourceInterface, error) {
 	// First check if the Submariner resource is present.
 	gvr, _ := schema.ParseResourceArg("submariners.v1alpha1.submariner.io")
-	list, err := clientSet.Resource(*gvr).Namespace(v1.NamespaceAll).List(context.TODO(), metav1.ListOptions{})
+	list, err := client.Resource(*gvr).Namespace(v1.NamespaceAll).List(context.TODO(), metav1.ListOptions{})
 	if apierrors.IsNotFound(err) || meta.IsNoMatchError(err) || (err == nil && len(list.Items) == 0) {
 		return nil, apierrors.NewNotFound(gvr.GroupResource(), "")
 	}
@@ -282,7 +259,7 @@ func (c *Controller) getCheckedClientset(kubeConfig *rest.Config) (dynamic.Resou
 	}
 
 	gvr, _ = schema.ParseResourceArg("gateways.v1.submariner.io")
-	gwClient := clientSet.Resource(*gvr).Namespace(v1.NamespaceAll)
+	gwClient := client.Resource(*gvr).Namespace(v1.NamespaceAll)
 	_, err = gwClient.List(context.TODO(), metav1.ListOptions{})
 
 	if apierrors.IsNotFound(err) || meta.IsNoMatchError(err) {
@@ -310,6 +287,6 @@ func (c *Controller) IsConnected(clusterID string) bool {
 	return !c.gatewayAvailable || c.getClusterStatusMap()[clusterID]
 }
 
-func (c *Controller) LocalClusterID() string {
+func (c *Controller) GetLocalClusterID() string {
 	return c.localClusterID.Load().(string)
 }

coredns/gateway/controller_test.go

@@ -35,7 +35,6 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/client-go/dynamic"
 	fakeClient "k8s.io/client-go/dynamic/fake"
-	"k8s.io/client-go/rest"
 )
 
 const (
@@ -209,17 +208,14 @@ func newTestDiver() *testDriver {
 
 	JustBeforeEach(func() {
 		t.controller = gateway.NewController()
-		t.controller.NewClientset = func(c *rest.Config) (dynamic.Interface, error) {
-			return t.dynClient, nil
-		}
 
 		if t.submarinerObj != nil {
 			_, err := t.dynClient.Resource(submarinersGVR).Namespace("submariner-operator").Create(context.TODO(), t.submarinerObj,
 				metav1.CreateOptions{})
 			Expect(err).To(Succeed())
 		}
 
-		Expect(t.controller.Start(&rest.Config{})).To(Succeed())
+		Expect(t.controller.Start(t.dynClient)).To(Succeed())
 	})
 
 	AfterEach(func() {
@@ -259,7 +255,7 @@ func (t *testDriver) localClusterIDUpdateValidationTest(originalLocalClusterID,
 
 func (t *testDriver) awaitValidLocalClusterID(clusterID string) {
 	Eventually(func() string {
-		return t.controller.LocalClusterID()
+		return t.controller.GetLocalClusterID()
 	}, 5).Should(Equal(clusterID))
 }
 

coredns/plugin/handler.go

@@ -26,7 +26,6 @@ import (
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/request"
 	"github.com/miekg/dns"
-	"github.com/submariner-io/lighthouse/coredns/serviceimport"
 )
 
 const PluginName = "lighthouse"
@@ -70,25 +69,10 @@ func (lh *Lighthouse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns
 func (lh *Lighthouse) getDNSRecord(ctx context.Context, zone string, state *request.Request, w dns.ResponseWriter,
 	r *dns.Msg, pReq *recordRequest,
 ) (int, error) {
-	var isHeadless bool
-	var (
-		dnsRecords []serviceimport.DNSRecord
-		found      bool
-		record     *serviceimport.DNSRecord
-	)
-
-	record, found = lh.getClusterIPForSvc(pReq)
+	dnsRecords, isHeadless, found := lh.Resolver.GetDNSRecords(pReq.namespace, pReq.service, pReq.cluster, pReq.hostname)
 	if !found {
-		dnsRecords, found = lh.EndpointSlices.GetDNSRecords(pReq.hostname, pReq.cluster, pReq.namespace,
-			pReq.service, lh.ClusterStatus.IsConnected)
-		if !found {
-			log.Debugf("No record found for %q", state.QName())
-			return lh.nextOrFailure(ctx, state, r, dns.RcodeNameError)
-		}
-
-		isHeadless = true
-	} else if record != nil && record.IP != "" {
-		dnsRecords = append(dnsRecords, *record)
+		log.Debugf("No record found for %q", state.QName())
+		return lh.nextOrFailure(ctx, state, r, dns.RcodeNameError)
 	}
 
 	if len(dnsRecords) == 0 {
@@ -102,7 +86,7 @@ func (lh *Lighthouse) getDNSRecord(ctx context.Context, zone string, state *requ
 	}
 
 	// Count records
-	localClusterID := lh.ClusterStatus.LocalClusterID()
+	localClusterID := lh.ClusterStatus.GetLocalClusterID()
 	for _, record := range dnsRecords {
 		incDNSQueryCounter(localClusterID, record.ClusterName, pReq.service, pReq.namespace, record.IP)
 	}