Adding wildcard support (#190)

* Commenting out unused functions. TODO: remove when it is not needed * Update README with namespace and template example * Adding note about changing the record name format via a template * Adding test scripts to automate k8s startup * Automating k8s namespace creation * Adding automation to start 4 k8s services * Updating documentation for k8s tests * Avoid downloading kubectl if already exists * Adding debug statement when namespace is not exposed. * Adding basic kubernetes integration tests * Makefile now contains a "testk8s" target. This target requires k8s to be running. * Adding test/kubernetes_test.go file with a couple of basic A record tests. * Updating k8s integration tests to only run k8s integration tests * Adding support for namespace wildcards * Refactoring to move filtering logic to kubernetes.go file * go fmt fixes * Adding wildcard support for namespaces and service names * Kubernetes integration tests updated for A records. * Expanded record name assembly for answer section not yet implemented. * Refactoring to focus k8sclient code just on accessing k8s API. Filtering now handled in kubernetes.go * Adding wildcard test cases * Adding skydns startup script. (To allow side by side testing of wildcards.) * Commenting out record name assmebly based on NameTemplate. Need to improve template before this makes sense. * Adding basic SRV integration tests * Need to add verification for additional answer section * Fixing comments and formatting * Moving wildcard constants to vars * Travis test execution appears to be failing on access to these constants * Fixing access to util package * Trying to work around Travis test bug * Reverting to access kubernetes/util as "util" Travis breakage is due to "Infoblox-CTO" in src path
2025-10-27 08:14:18 -04:00 · 2016-07-14 14:50:14 -07:00
parent 319d30697a
commit 3f4ec783d2
17 changed files with 527 additions and 67 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ query.log
 Corefile
 *.swp
 coredns
+kubectl
--- a/7
+++ b/7
@@ -2,7 +2,7 @@
 BUILD_VERBOSE := -v

 TEST_VERBOSE :=
-#TEST_VERBOSE := -v
+TEST_VERBOSE := -v

 all:
 	go build $(BUILD_VERBOSE)
@@ -20,6 +20,11 @@ deps:
 test:
 	go test $(TEST_VERBOSE) ./...

+.PHONY: testk8s
+testk8s:
+#	go test $(TEST_VERBOSE) -tags=k8sIntegration ./...
+	go test $(TEST_VERBOSE) -tags=k8sIntegration -run 'TestK8sIntegration' ./test
+
 .PHONY: clean
 clean:
 	go clean
--- a/middleware/kubernetes/README.md
+++ b/middleware/kubernetes/README.md
@@ -7,6 +7,7 @@ are constructed as "myservice.mynamespace.coredns.local" where:
 * "mynamespace" is the k8s namespace for the service, and
 * "coredns.local" is the zone configured for `kubernetes`.

+The record name format can be changed by specifying a name template in the Corefile.

 ## Syntax

@@ -36,6 +37,10 @@ This is the default kubernetes setup, with everything specified in full:
    kubernetes coredns.local {
        # Use url for k8s API endpoint
        endpoint http://localhost:8080
+        # Assemble k8s record names with the template
+        template {service}.{namespace}.{zone}
+        # Only expose the k8s namespace "demo"
+        namespaces demo
    }
 #    cache 160 coredns.local
 }
@@ -247,7 +252,7 @@ return the IP addresses for all services with "nginx" in the service name.

 TBD:
 * How does this relate the the k8s load-balancer configuration?
-* Do wildcards search across namespaces?
+* Do wildcards search across namespaces? (Yes)
 * Initial implementation assumes that a namespace maps to the first DNS label
  below the zone managed by the kubernetes middleware. This assumption may
  need to be revised.
@@ -344,4 +349,5 @@ TBD:
 	  and A-record queries. Automate testing with cache in place.
 	* Automate CoreDNS performance tests. Initially for zone files, and for
 	  pre-loaded k8s API cache.
-    * Automate integration testing with kubernetes.
+    * Automate integration testing with kubernetes. (k8s launch and service start-up
+      automation is in middleware/kubernetes/tests)
--- a/middleware/kubernetes/handler.go
+++ b/middleware/kubernetes/handler.go
@@ -10,7 +10,6 @@ import (
 )

 func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
-
 	fmt.Printf("[debug] here entering ServeDNS: ctx:%v dnsmsg:%v\n", ctx, r)

 	state := middleware.State{W: w, Req: r}
--- a/middleware/kubernetes/k8sclient/k8sclient.go
+++ b/middleware/kubernetes/k8sclient/k8sclient.go
@@ -117,30 +117,6 @@ func (c *K8sConnector) GetServicesByNamespace() (map[string][]ServiceItem, error
 	return items, nil
 }

-// GetServiceItemsInNamespace returns the ServiceItems that match
-// servicename in the namespace
-func (c *K8sConnector) GetServiceItemsInNamespace(namespace string, servicename string) ([]*ServiceItem, error) {
-
-	itemMap, err := c.GetServicesByNamespace()
-
-	if err != nil {
-		fmt.Printf("[ERROR] Getting service list produced error: %v", err)
-		return nil, err
-	}
-
-	// TODO: Handle case where namespace == nil
-
-	var serviceItems []*ServiceItem
-
-	for _, x := range itemMap[namespace] {
-		if x.Metadata.Name == servicename {
-			serviceItems = append(serviceItems, &x)
-		}
-	}
-
-	return serviceItems, nil
-}
-
 func NewK8sConnector(baseURL string) *K8sConnector {
 	k := new(K8sConnector)

--- a/middleware/kubernetes/kubernetes.go
+++ b/middleware/kubernetes/kubernetes.go
@@ -62,7 +62,7 @@ func (g Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
 		typeName    string
 	)

-	fmt.Println("enter Records('", name, "', ", exact, ")")
+	fmt.Println("[debug] enter Records('", name, "', ", exact, ")")
 	zone, serviceSegments := g.getZoneForName(name)

 	/*
@@ -83,6 +83,18 @@ func (g Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
 	serviceName = g.NameTemplate.GetServiceFromSegmentArray(serviceSegments)
 	typeName = g.NameTemplate.GetTypeFromSegmentArray(serviceSegments)

+	if namespace == "" {
+		err := errors.New("Parsing query string did not produce a namespace value. Assuming wildcard namespace.")
+		fmt.Printf("[WARN] %v\n", err)
+		namespace = util.WildcardStar
+	}
+
+	if serviceName == "" {
+		err := errors.New("Parsing query string did not produce a serviceName value. Assuming wildcard serviceName.")
+		fmt.Printf("[WARN] %v\n", err)
+		serviceName = util.WildcardStar
+	}
+
 	fmt.Println("[debug] exact: ", exact)
 	fmt.Println("[debug] zone: ", zone)
 	fmt.Println("[debug] servicename: ", serviceName)
@@ -90,21 +102,18 @@ func (g Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
 	fmt.Println("[debug] typeName: ", typeName)
 	fmt.Println("[debug] APIconn: ", g.APIConn)

-	// TODO: Implement wildcard support to allow blank namespace value
-	if namespace == "" {
-		err := errors.New("Parsing query string did not produce a namespace value")
-		fmt.Printf("[ERROR] %v\n", err)
-		return nil, err
-	}
+	nsWildcard := util.SymbolContainsWildcard(namespace)
+	serviceWildcard := util.SymbolContainsWildcard(serviceName)

-	// Abort if the namespace is not published per CoreFile
-	if g.Namespaces != nil && !util.StringInSlice(namespace, *g.Namespaces) {
+	// Abort if the namespace does not contain a wildcard, and namespace is not published per CoreFile
+	// Case where namespace contains a wildcard is handled in Get(...) method.
+	if (!nsWildcard) && (g.Namespaces != nil && !util.StringInSlice(namespace, *g.Namespaces)) {
+		fmt.Printf("[debug] Namespace '%v' is not published by Corefile\n", namespace)
 		return nil, nil
 	}

-	k8sItems, err := g.APIConn.GetServiceItemsInNamespace(namespace, serviceName)
+	k8sItems, err := g.Get(namespace, nsWildcard, serviceName, serviceWildcard)
 	fmt.Println("[debug] k8s items:", k8sItems)
-
 	if err != nil {
 		fmt.Printf("[ERROR] Got error while looking up ServiceItems. Error is: %v\n", err)
 		return nil, err
@@ -114,29 +123,27 @@ func (g Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
 		return nil, nil
 	}

-	//	test := g.NameTemplate.GetRecordNameFromNameValues(nametemplate.NameValues{ServiceName: serviceName, TypeName: typeName, Namespace: namespace, Zone: zone})
-	//	fmt.Printf("[debug] got recordname %v\n", test)
-
-	records := g.getRecordsForServiceItems(k8sItems, name)
-
+	records := g.getRecordsForServiceItems(k8sItems, nametemplate.NameValues{TypeName: typeName, ServiceName: serviceName, Namespace: namespace, Zone: zone})
 	return records, nil
 }

 // TODO: assemble name from parts found in k8s data based on name template rather than reusing query string
-func (g Kubernetes) getRecordsForServiceItems(serviceItems []*k8sc.ServiceItem, name string) []msg.Service {
+func (g Kubernetes) getRecordsForServiceItems(serviceItems []k8sc.ServiceItem, values nametemplate.NameValues) []msg.Service {
 	var records []msg.Service

 	for _, item := range serviceItems {
-		fmt.Println("[debug] clusterIP:", item.Spec.ClusterIP)
+		clusterIP := item.Spec.ClusterIP
+		fmt.Println("[debug] clusterIP:", clusterIP)
+
+		// Create records by constructing record name from template...
+		//values.Namespace = item.Metadata.Namespace
+		//values.ServiceName = item.Metadata.Name
+		//s := msg.Service{Host: g.NameTemplate.GetRecordNameFromNameValues(values)}
+		//records = append(records, s)
+
+		// Create records for each exposed port...
 		for _, p := range item.Spec.Ports {
 			fmt.Println("[debug]    port:", p.Port)
-		}
-
-		clusterIP := item.Spec.ClusterIP
-
-		s := msg.Service{Host: name}
-		records = append(records, s)
-		for _, p := range item.Spec.Ports {
 			s := msg.Service{Host: clusterIP, Port: p.Port}
 			records = append(records, s)
 		}
@@ -146,17 +153,50 @@ func (g Kubernetes) getRecordsForServiceItems(serviceItems []*k8sc.ServiceItem,
 	return records
 }

-/*
 // Get performs the call to the Kubernetes http API.
-func (g Kubernetes) Get(path string, recursive bool) (bool, error) {
+func (g Kubernetes) Get(namespace string, nsWildcard bool, servicename string, serviceWildcard bool) ([]k8sc.ServiceItem, error) {
+	serviceList, err := g.APIConn.GetServiceList()

-    fmt.Println("[debug] in Get path: ", path)
-    fmt.Println("[debug] in Get recursive: ", recursive)
+	if err != nil {
+		fmt.Printf("[ERROR] Getting service list produced error: %v", err)
+		return nil, err
+	}

-	return false, nil
+	var resultItems []k8sc.ServiceItem
+
+	for _, item := range serviceList.Items {
+		if symbolMatches(namespace, item.Metadata.Namespace, nsWildcard) && symbolMatches(servicename, item.Metadata.Name, serviceWildcard) {
+			// If namespace has a wildcard, filter results against Corefile namespace list.
+			// (Namespaces without a wildcard were filtered before the call to this function.)
+			if nsWildcard && (g.Namespaces != nil && !util.StringInSlice(item.Metadata.Namespace, *g.Namespaces)) {
+				fmt.Printf("[debug] Namespace '%v' is not published by Corefile\n", item.Metadata.Namespace)
+				continue
+			}
+			resultItems = append(resultItems, item)
+		}
+	}
+
+	return resultItems, nil
 }
-*/

+func symbolMatches(queryString string, candidateString string, wildcard bool) bool {
+	result := false
+	switch {
+	case !wildcard:
+		result = (queryString == candidateString)
+	case queryString == util.WildcardStar:
+		result = true
+	case queryString == util.WildcardAny:
+		result = true
+	}
+	return result
+}
+
+// TODO: Remove these unused functions. One is related to Ttl calculation
+//       Implement Ttl and priority calculation based on service count before
+//       removing this code.
+/*
+// splitDNSName separates the name into DNS segments and reverses the segments.
 func (g Kubernetes) splitDNSName(name string) []string {
 	l := dns.SplitDomainName(name)

@@ -166,16 +206,15 @@ func (g Kubernetes) splitDNSName(name string) []string {

 	return l
 }
-
+*/
 // skydns/local/skydns/east/staging/web
 // skydns/local/skydns/west/production/web
 //
 // skydns/local/skydns/*/*/web
 // skydns/local/skydns/*/web
-
+/*
 // loopNodes recursively loops through the nodes and returns all the values. The nodes' keyname
 // will be match against any wildcards when star is true.
-/*
 func (g Kubernetes) loopNodes(ns []*etcdc.Node, nameParts []string, star bool, bx map[msg.Service]bool) (sx []msg.Service, err error) {
 	if bx == nil {
 		bx = make(map[msg.Service]bool)
--- a/middleware/kubernetes/test/00_run_k8s.sh
+++ b/middleware/kubernetes/test/00_run_k8s.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+# Based on instructions at: http://kubernetes.io/docs/getting-started-guides/docker/
+
+#K8S_VERSION=$(curl -sS https://storage.googleapis.com/kubernetes-release/release/latest.txt)
+K8S_VERSION="v1.2.4"
+
+ARCH="amd64"
+
+
+export K8S_VERSION
+export ARCH
+
+#RUN_SKYDNS="yes"
+RUN_SKYDNS="no"
+
+if [ "${RUN_SKYDNS}" = "yes" ]; then
+	DNS_ARGUMENTS="--cluster-dns=10.0.0.10 --cluster-domain=cluster.local"
+else
+	DNS_ARGUMENTS=""
+fi
+
+docker run -d \
+    --volume=/:/rootfs:ro \
+    --volume=/sys:/sys:ro \
+    --volume=/var/lib/docker/:/var/lib/docker:rw \
+    --volume=/var/lib/kubelet/:/var/lib/kubelet:rw \
+    --volume=/var/run:/var/run:rw \
+    --net=host \
+    --pid=host \
+    --privileged \
+    gcr.io/google_containers/hyperkube-${ARCH}:${K8S_VERSION} \
+    /hyperkube kubelet \
+    --containerized \
+    --hostname-override=127.0.0.1 \
+    --api-servers=http://localhost:8080 \
+    --config=/etc/kubernetes/manifests \
+    ${DNS_ARGUMENTS} \
+    --allow-privileged --v=2
--- a/middleware/kubernetes/test/10_setup_kubectl.sh
+++ b/middleware/kubernetes/test/10_setup_kubectl.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+PWD=`pwd`
+BASEDIR=`realpath $(dirname ${0})`
+
+cd ${BASEDIR}
+if [ ! -e kubectl ]; then
+	curl -O http://storage.googleapis.com/kubernetes-release/release/v1.2.4/bin/linux/amd64/kubectl
+	chmod u+x kubectl
+fi
+
+${BASEDIR}/kubectl config set-cluster test-doc --server=http://localhost:8080
+${BASEDIR}/kubectl config set-context test-doc --cluster=test-doc
+${BASEDIR}/kubectl config use-context test-doc
+
+cd ${PWD}
+
+alias kubctl="${BASEDIR}/kubectl"
--- a/middleware/kubernetes/test/15_run_skydns.sh
+++ b/middleware/kubernetes/test/15_run_skydns.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+# Running skydns based on instructions at: https://testdatamanagement.wordpress.com/2015/09/01/running-kubernetes-in-docker-with-dns-on-a-single-node/
+
+KUBECTL='./kubectl'
+
+#RUN_SKYDNS="yes"
+RUN_SKYDNS="no"
+
+wait_until_k8s_ready() {
+	# Wait until kubernetes is up and fully responsive
+	while :
+	do
+   	 ${KUBECTL} get nodes 2>/dev/null | grep -q '127.0.0.1'
+		if [ "${?}" = "0" ]; then
+			break
+		else
+			echo "sleeping for 5 seconds"
+			sleep 5
+		fi
+	done
+	echo "kubernetes nodes:"
+	${KUBECTL} get nodes
+}
+
+
+if [ "${RUN_SKYDNS}" = "yes" ]; then
+	wait_until_k8s_ready
+
+	echo "Launch kube2sky..."
+	docker run -d --net=host gcr.io/google_containers/kube2sky:1.11 --kube_master_url=http://127.0.0.1:8080 --domain=cluster.local
+
+	echo ""
+
+	echo "Launch SkyDNS..."
+	docker run -d --net=host gcr.io/google_containers/skydns:2015-03-11-001 --machines=http://localhost:4001 --addr=0.0.0.0:53 --domain=cluster.local
+else
+	true
+fi
--- a/middleware/kubernetes/test/20_setup_k8s_services.sh
+++ b/middleware/kubernetes/test/20_setup_k8s_services.sh
@@ -0,0 +1,80 @@
+#!/bin/bash
+
+KUBECTL='./kubectl'
+
+wait_until_k8s_ready() {
+	# Wait until kubernetes is up and fully responsive
+	while :
+	do
+   	 ${KUBECTL} get nodes 2>/dev/null | grep -q '127.0.0.1'
+		if [ "${?}" = "0" ]; then
+			break
+		else
+			echo "sleeping for 5 seconds"
+			sleep 5
+		fi
+	done
+	echo "kubernetes nodes:"
+	${KUBECTL} get nodes
+}
+
+create_namespaces() {
+	for n in ${NAMESPACES};
+	do
+			echo "Creating namespace: ${n}"
+			${KUBECTL} get namespaces --no-headers 2>/dev/null | grep -q ${n}
+			if [ "${?}" != "0" ]; then
+				${KUBECTL} create namespace ${n}
+			fi
+	done
+
+	echo "kubernetes namespaces:"
+	${KUBECTL} get namespaces
+}
+
+# run_and_expose_service <servicename> <namespace> <image> <port>
+run_and_expose_service() {
+
+    if [ "${#}" != "4" ]; then
+        return -1
+    fi
+
+    service="${1}"
+    namespace="${2}"
+    image="${3}"
+    port="${4}"
+
+    echo "   starting service '${service}' in namespace '${namespace}"
+
+    ${KUBECTL} get deployment --namespace=${namespace} --no-headers 2>/dev/null | grep -q ${service}
+    if [ "${?}" != "0" ]; then
+        ${KUBECTL} run ${service} --namespace=${namespace} --image=${image}
+    else
+        echo "warn: service '${service}' already running in namespace '${namespace}'"
+    fi
+
+    ${KUBECTL} get service --namespace=${namespace} --no-headers 2>/dev/null | grep -q ${service}
+    if [ "${?}" != "0" ]; then
+        ${KUBECTL} expose deployment ${service} --namespace=${namespace} --port=${port}
+    else
+        echo "warn: service '${service}' already exposed in namespace '${namespace}'"
+    fi
+}
+
+
+wait_until_k8s_ready
+
+NAMESPACES="demo test"
+create_namespaces
+
+echo ""
+echo "Starting services:"
+
+run_and_expose_service mynginx demo nginx 80
+run_and_expose_service webserver demo nginx 80
+run_and_expose_service mynginx test nginx 80
+run_and_expose_service webserver test nginx 80
+
+echo ""
+echo "Services exposed:"
+${KUBECTL} get services --all-namespaces
--- a/middleware/kubernetes/test/README.md
+++ b/middleware/kubernetes/test/README.md
@@ -0,0 +1,35 @@
+## Test scripts to automate kubernetes startup
+
+Requirements:
+	docker
+	curl
+
+The scripts in this directory startup kubernetes with docker as the container runtime.
+After starting kubernetes, a couple of kubernetes services are started to allow automatic
+testing of CoreDNS with kubernetes.
+
+To use, run the scripts as:
+
+~~~
+$ ./00_run_k8s.sh && ./10_setup_kubectl.sh && ./20_setup_k8s_services.sh
+~~~
+
+After running the above scripts, kubernetes will be running on the localhost with the following services
+exposed:
+
+~~
+NAMESPACE   NAME         CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
+default     kubernetes   10.0.0.1     <none>        443/TCP   48m
+demo        mynginx      10.0.0.168   <none>        80/TCP    9m
+demo        webserver    10.0.0.28    <none>        80/TCP    2m
+test        mynginx      10.0.0.4     <none>        80/TCP    2m
+test        webserver    10.0.0.39    <none>        80/TCP    2m
+~~
+
+
+Kubernetes and all running containers can be uncerimoniously stopped by
+running the `kill_all_containers.sh` script.
+
+~~~
+$ ./kill_all_containers.sh
+~~~
--- a/middleware/kubernetes/test/kill_all_containers.sh
+++ b/middleware/kubernetes/test/kill_all_containers.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+docker rm -f $(docker ps -a -q)
+sleep 1
+docker rm -f $(docker ps -a -q)
--- a/middleware/kubernetes/util/util.go
+++ b/middleware/kubernetes/util/util.go
@@ -1,6 +1,10 @@
 // Package kubernetes/util provides helper functions for the kubernetes middleware
 package util

+import (
+	"strings"
+)
+
 // StringInSlice check whether string a is a member of slice.
 func StringInSlice(a string, slice []string) bool {
 	for _, b := range slice {
@@ -10,3 +14,13 @@ func StringInSlice(a string, slice []string) bool {
 	}
 	return false
 }
+
+// SymbolContainsWildcard checks whether symbol contains a wildcard value
+func SymbolContainsWildcard(symbol string) bool {
+	return (strings.Contains(symbol, WildcardStar) || (symbol == WildcardAny))
+}
+
+const (
+	WildcardStar = "*"
+	WildcardAny  = "any"
+)
--- a/middleware/kubernetes/util/util_test.go
+++ b/middleware/kubernetes/util/util_test.go
@@ -31,3 +31,25 @@ func TestStringInSlice(t *testing.T) {
 		}
 	}
 }
+
+// Test data for TestSymbolContainsWildcard cases.
+var testdataSymbolContainsWildcard = []struct {
+	Symbol         string
+	ExpectedResult bool
+}{
+	{"mynamespace", false},
+	{"*", true},
+	{"any", true},
+	{"my*space", true},
+	{"*space", true},
+	{"myname*", true},
+}
+
+func TestSymbolContainsWildcard(t *testing.T) {
+	for _, example := range testdataSymbolContainsWildcard {
+		actualResult := SymbolContainsWildcard(example.Symbol)
+		if actualResult != example.ExpectedResult {
+			t.Errorf("Expected SymbolContainsWildcard result '%v' for example string='%v'. Instead got result '%v'.", example.ExpectedResult, example.Symbol, actualResult)
+		}
+	}
+}
--- a/test/kubernetes_test.go
+++ b/test/kubernetes_test.go
@@ -0,0 +1,182 @@
+// +build k8sIntegration
+
+package test
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"testing"
+
+	"github.com/miekg/dns"
+)
+
+// Test data for A records
+var testdataLookupA = []struct {
+	Query            string
+	TotalAnswerCount int
+	ARecordCount     int
+}{
+	// Matching queries
+	{"mynginx.demo.coredns.local.", 1, 1}, // One A record, should exist
+
+	// Failure queries
+	{"mynginx.test.coredns.local.", 0, 0},                     // One A record, is not exposed
+	{"someservicethatdoesnotexist.demo.coredns.local.", 0, 0}, // Record does not exist
+
+	// Namespace wildcards
+	{"mynginx.*.coredns.local.", 1, 1},                       // One A record, via wildcard namespace
+	{"mynginx.any.coredns.local.", 1, 1},                     // One A record, via wildcard namespace
+	{"someservicethatdoesnotexist.*.coredns.local.", 0, 0},   // Record does not exist with wildcard for namespace
+	{"someservicethatdoesnotexist.any.coredns.local.", 0, 0}, // Record does not exist with wildcard for namespace
+	{"*.demo.coredns.local.", 2, 2},                          // Two A records, via wildcard
+	{"any.demo.coredns.local.", 2, 2},                        // Two A records, via wildcard
+	{"*.test.coredns.local.", 0, 0},                          // Two A record, via wildcard that is not exposed
+	{"any.test.coredns.local.", 0, 0},                        // Two A record, via wildcard that is not exposed
+	{"*.*.coredns.local.", 2, 2},                             // Two A records, via namespace and service wildcard
+}
+
+// Test data for SRV records
+var testdataLookupSRV = []struct {
+	Query            string
+	TotalAnswerCount int
+	//	ARecordCount     int
+	SRVRecordCount int
+}{
+	// Matching queries
+	{"mynginx.demo.coredns.local.", 1, 1}, // One SRV record, should exist
+
+	// Failure queries
+	{"mynginx.test.coredns.local.", 0, 0},                     // One SRV record, is not exposed
+	{"someservicethatdoesnotexist.demo.coredns.local.", 0, 0}, // Record does not exist
+
+	// Namespace wildcards
+	{"mynginx.*.coredns.local.", 1, 1},                       // One SRV record, via wildcard namespace
+	{"mynginx.any.coredns.local.", 1, 1},                     // One SRV record, via wildcard namespace
+	{"someservicethatdoesnotexist.*.coredns.local.", 0, 0},   // Record does not exist with wildcard for namespace
+	{"someservicethatdoesnotexist.any.coredns.local.", 0, 0}, // Record does not exist with wildcard for namespace
+	{"*.demo.coredns.local.", 1, 1},                          // One SRV record, via wildcard
+	{"any.demo.coredns.local.", 1, 1},                        // One SRV record, via wildcard
+	{"*.test.coredns.local.", 0, 0},                          // One SRV record, via wildcard that is not exposed
+	{"any.test.coredns.local.", 0, 0},                        // One SRV record, via wildcard that is not exposed
+	{"*.*.coredns.local.", 1, 1},                             // One SRV record, via namespace and service wildcard
+}
+
+// checkKubernetesRunning performs a basic
+func checkKubernetesRunning() bool {
+	_, err := http.Get("http://localhost:8080/api/v1")
+	return err == nil
+}
+
+func TestK8sIntegration(t *testing.T) {
+	t.Log("   === RUN testLookupA")
+	testLookupA(t)
+	t.Log("   === RUN testLookupSRV")
+	testLookupSRV(t)
+}
+
+func testLookupA(t *testing.T) {
+	if !checkKubernetesRunning() {
+		t.Skip("Skipping Kubernetes Integration tests. Kubernetes is not running")
+	}
+
+	// Note: Use different port to avoid conflict with servers used in other tests.
+	coreFile :=
+		`.:2053 {
+    kubernetes coredns.local {
+		endpoint http://localhost:8080
+		namespaces demo
+    }
+`
+
+	server, _, udp, err := Server(t, coreFile)
+	if err != nil {
+		t.Fatal("Could not get server: %s", err)
+	}
+	defer server.Stop()
+
+	log.SetOutput(ioutil.Discard)
+
+	for _, testData := range testdataLookupA {
+		t.Logf("[log] Testing query string: '%v'\n", testData.Query)
+		dnsClient := new(dns.Client)
+		dnsMessage := new(dns.Msg)
+
+		dnsMessage.SetQuestion(testData.Query, dns.TypeA)
+		dnsMessage.SetEdns0(4096, true)
+
+		res, _, err := dnsClient.Exchange(dnsMessage, udp)
+		if err != nil {
+			t.Fatal("Could not send query: %s", err)
+		}
+		// Count A records in the answer section
+		ARecordCount := 0
+		for _, a := range res.Answer {
+			if a.Header().Rrtype == dns.TypeA {
+				ARecordCount++
+			}
+		}
+
+		if ARecordCount != testData.ARecordCount {
+			t.Errorf("Expected '%v' A records in response. Instead got '%v' A records. Test query string: '%v'", testData.ARecordCount, ARecordCount, testData.Query)
+		}
+		if len(res.Answer) != testData.TotalAnswerCount {
+			t.Errorf("Expected '%v' records in answer section. Instead got '%v' records in answer section. Test query string: '%v'", testData.TotalAnswerCount, len(res.Answer), testData.Query)
+		}
+	}
+}
+
+func testLookupSRV(t *testing.T) {
+	if !checkKubernetesRunning() {
+		t.Skip("Skipping Kubernetes Integration tests. Kubernetes is not running")
+	}
+
+	// Note: Use different port to avoid conflict with servers used in other tests.
+	coreFile :=
+		`.:2054 {
+    kubernetes coredns.local {
+		endpoint http://localhost:8080
+		namespaces demo
+    }
+`
+
+	server, _, udp, err := Server(t, coreFile)
+	if err != nil {
+		t.Fatal("Could not get server: %s", err)
+	}
+	defer server.Stop()
+
+	log.SetOutput(ioutil.Discard)
+
+	// TODO: Add checks for A records in additional section
+
+	for _, testData := range testdataLookupSRV {
+		t.Logf("[log] Testing query string: '%v'\n", testData.Query)
+		dnsClient := new(dns.Client)
+		dnsMessage := new(dns.Msg)
+
+		dnsMessage.SetQuestion(testData.Query, dns.TypeSRV)
+		dnsMessage.SetEdns0(4096, true)
+
+		res, _, err := dnsClient.Exchange(dnsMessage, udp)
+		if err != nil {
+			t.Fatal("Could not send query: %s", err)
+		}
+		// Count SRV records in the answer section
+		srvRecordCount := 0
+		for _, a := range res.Answer {
+			fmt.Printf("RR: %v\n", a)
+			if a.Header().Rrtype == dns.TypeSRV {
+				srvRecordCount++
+			}
+		}
+
+		if srvRecordCount != testData.SRVRecordCount {
+			t.Errorf("Expected '%v' SRV records in response. Instead got '%v' SRV records. Test query string: '%v'", testData.SRVRecordCount, srvRecordCount, testData.Query)
+		}
+		if len(res.Answer) != testData.TotalAnswerCount {
+			t.Errorf("Expected '%v' records in answer section. Instead got '%v' records in answer section. Test query string: '%v'", testData.TotalAnswerCount, len(res.Answer), testData.Query)
+		}
+	}
+}