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

12 files changed, 332 insertions, 60 deletions

diff --git a/middleware/kubernetes/README.md b/middleware/kubernetes/README.md
index c5ba32f72..2f2f7341d 100644
--- 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)
diff --git a/middleware/kubernetes/handler.go b/middleware/kubernetes/handler.go
index 168b65508..49d1c1573 100644
--- 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}
diff --git a/middleware/kubernetes/k8sclient/k8sclient.go b/middleware/kubernetes/k8sclient/k8sclient.go
index 95300f3b9..cb1d0fe4a 100644
--- 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)
 
diff --git a/middleware/kubernetes/kubernetes.go b/middleware/kubernetes/kubernetes.go
index d6d93f809..f9a0712fe 100644
--- 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)
-		for _, p := range item.Spec.Ports {
-			fmt.Println("[debug]    port:", p.Port)
-		}
-
 		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)
 
-		s := msg.Service{Host: name}
-		records = append(records, s)
+		// Create records for each exposed port...
 		for _, p := range item.Spec.Ports {
+			fmt.Println("[debug]    port:", p.Port)
 			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)
diff --git a/middleware/kubernetes/test/00_run_k8s.sh b/middleware/kubernetes/test/00_run_k8s.sh
new file mode 100755
index 000000000..3753cbd8e
--- /dev/null
+++ 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
diff --git a/middleware/kubernetes/test/10_setup_kubectl.sh b/middleware/kubernetes/test/10_setup_kubectl.sh
new file mode 100755
index 000000000..c47b779a3
--- /dev/null
+++ 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"
diff --git a/middleware/kubernetes/test/15_run_skydns.sh b/middleware/kubernetes/test/15_run_skydns.sh
new file mode 100755
index 000000000..b88cf8f9b
--- /dev/null
+++ 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
diff --git a/middleware/kubernetes/test/20_setup_k8s_services.sh b/middleware/kubernetes/test/20_setup_k8s_services.sh
new file mode 100755
index 000000000..0d067cf26
--- /dev/null
+++ 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
diff --git a/middleware/kubernetes/test/README.md b/middleware/kubernetes/test/README.md
new file mode 100644
index 000000000..eea1bf7d3
--- /dev/null
+++ 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
+~~~
diff --git a/middleware/kubernetes/test/kill_all_containers.sh b/middleware/kubernetes/test/kill_all_containers.sh
new file mode 100755
index 000000000..aa7f4255d
--- /dev/null
+++ 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)
diff --git a/middleware/kubernetes/util/util.go b/middleware/kubernetes/util/util.go
index 7fc03ffc1..259eaf596 100644
--- 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"
+)
diff --git a/middleware/kubernetes/util/util_test.go b/middleware/kubernetes/util/util_test.go
index b53b9f3f6..4af64ea50 100644
--- 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)
+		}
+	}
+}