middleware/kubernetes: cleanup (#818)

Drop the interfaceAddr interfaces and just use a function. Cleanup
all fallout from that. Remove the use of global variables and cleanup
the tests a bit.

8 files changed, 25 insertions, 53 deletions

diff --git a/middleware/kubernetes/federation.go b/middleware/kubernetes/federation.go
index 4c058b839..6f7e5f122 100644
--- a/middleware/kubernetes/federation.go
+++ b/middleware/kubernetes/federation.go
@@ -13,10 +13,6 @@ type Federation struct {
 	zone string
 }
 
-var localNodeName string
-var federationZone string
-var federationRegion string
-
 const (
 	// TODO: Do not hardcode these labels. Pull them out of the API instead.
 	//
@@ -80,21 +76,18 @@ func (k *Kubernetes) federationCNAMERecord(r recordRequest) msg.Service {
 }
 
 func (k *Kubernetes) localNodeName() string {
-	if localNodeName != "" {
-		return localNodeName
-	}
-	localIP := k.localPodIP()
+	localIP := k.interfaceAddrsFunc()
 	if localIP == nil {
 		return ""
 	}
+
 	// Find endpoint matching localIP
 	endpointsList := k.APIConn.EndpointsList()
 	for _, ep := range endpointsList.Items {
 		for _, eps := range ep.Subsets {
 			for _, addr := range eps.Addresses {
 				if localIP.Equal(net.ParseIP(addr.IP)) {
-					localNodeName = *addr.NodeName
-					return localNodeName
+					return *addr.NodeName
 				}
 			}
 		}
diff --git a/middleware/kubernetes/federation_test.go b/middleware/kubernetes/federation_test.go
index a938159ff..95dbc9024 100644
--- a/middleware/kubernetes/federation_test.go
+++ b/middleware/kubernetes/federation_test.go
@@ -88,11 +88,9 @@ func TestFederationCNAMERecord(t *testing.T) {
 	k := Kubernetes{Zones: []string{"inter.webs"}}
 	k.Federations = []Federation{{name: "fed", zone: "era.tion.com"}}
 	k.APIConn = apiConnFedTest{}
+	k.interfaceAddrsFunc = func() net.IP { return net.ParseIP("10.9.8.7") }
 
-	var r recordRequest
-
-	r, _ = k.parseRequest("s1.ns.fed.svc.inter.webs", dns.TypeA)
-	localPodIP = net.ParseIP("10.9.8.7")
+	r, _ := k.parseRequest("s1.ns.fed.svc.inter.webs", dns.TypeA)
 	testFederationCNAMERecord(t, k, r, msg.Service{Key: "/coredns/webs/inter/svc/fed/ns/s1", Host: "s1.ns.fed.svc.fd-az.fd-r.era.tion.com"})
 
 	r, _ = k.parseRequest("ep1.s1.ns.fed.svc.inter.webs", dns.TypeA)
@@ -100,5 +98,4 @@ func TestFederationCNAMERecord(t *testing.T) {
 
 	r, _ = k.parseRequest("ep1.s1.ns.foo.svc.inter.webs", dns.TypeA)
 	testFederationCNAMERecord(t, k, r, msg.Service{Key: "", Host: ""})
-
 }
diff --git a/middleware/kubernetes/handler_test.go b/middleware/kubernetes/handler_test.go
index 8d9417b8d..9e38bc59f 100644
--- a/middleware/kubernetes/handler_test.go
+++ b/middleware/kubernetes/handler_test.go
@@ -269,7 +269,7 @@ func TestServeDNS(t *testing.T) {
 	k.APIConn = &APIConnServeTest{}
 	k.AutoPath.Enabled = true
 	k.AutoPath.HostSearchPath = []string{"hostdom.test"}
-	//k.Proxy = test.MockHandler(nextMWMap)
+	k.interfaceAddrsFunc = localPodIP
 	k.Next = testHandler(nextMWMap)
 
 	ctx := context.TODO()
diff --git a/middleware/kubernetes/kubernetes.go b/middleware/kubernetes/kubernetes.go
index 58d3656ae..8a87322e8 100644
--- a/middleware/kubernetes/kubernetes.go
+++ b/middleware/kubernetes/kubernetes.go
@@ -46,7 +46,7 @@ type Kubernetes struct {
 	ReverseCidrs  []net.IPNet
 	Fallthrough   bool
 	AutoPath
-	interfaceAddrs interfaceAddrser
+	interfaceAddrsFunc func() net.IP
 }
 
 type AutoPath struct {
@@ -98,8 +98,6 @@ type recordRequest struct {
 	federation string
 }
 
-var localPodIP net.IP
-
 var (
 	errNoItems           = errors.New("no items found")
 	errNsNotExposed      = errors.New("namespace is not exposed")
@@ -651,11 +649,11 @@ func symbolContainsWildcard(symbol string) bool {
 	return (symbol == "*" || symbol == "any")
 }
 
-func (k *Kubernetes) localPodIP() net.IP {
-	if localPodIP != nil {
-		return localPodIP
+func localPodIP() net.IP {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return nil
 	}
-	addrs, _ := k.interfaceAddrs.interfaceAddrs()
 
 	for _, addr := range addrs {
 		ip, _, _ := net.ParseCIDR(addr.String())
@@ -663,8 +661,7 @@ func (k *Kubernetes) localPodIP() net.IP {
 		if ip == nil || ip.IsLoopback() {
 			continue
 		}
-		localPodIP = ip
-		return localPodIP
+		return ip
 	}
 	return nil
 }
diff --git a/middleware/kubernetes/kubernetes_test.go b/middleware/kubernetes/kubernetes_test.go
index 530e2234e..c93270cbe 100644
--- a/middleware/kubernetes/kubernetes_test.go
+++ b/middleware/kubernetes/kubernetes_test.go
@@ -432,6 +432,7 @@ func TestServices(t *testing.T) {
 
 	k := Kubernetes{Zones: []string{"interwebs.test"}}
 	k.Federations = []Federation{{name: "fed", zone: "era.tion.com"}}
+	k.interfaceAddrsFunc = localPodIP
 	k.APIConn = &APIConnServiceTest{}
 
 	type svcAns struct {
diff --git a/middleware/kubernetes/ns.go b/middleware/kubernetes/ns.go
index af6f83f21..488713d8b 100644
--- a/middleware/kubernetes/ns.go
+++ b/middleware/kubernetes/ns.go
@@ -41,25 +41,15 @@ func isDefaultNS(name string, r recordRequest) bool {
 }
 
 func (k *Kubernetes) coreDNSRecord() dns.A {
-	var localIP net.IP
-	var svcName string
-	var svcNamespace string
-	var dnsIP net.IP
+	var (
+		svcName      string
+		svcNamespace string
+		dnsIP        net.IP
+	)
 
 	if len(corednsRecord.Hdr.Name) == 0 || corednsRecord.A == nil {
 		// get local Pod IP
-		addrs, _ := k.interfaceAddrs.interfaceAddrs()
-
-		for _, addr := range addrs {
-			ip, _, _ := net.ParseCIDR(addr.String())
-			ip = ip.To4()
-
-			if ip == nil || ip.IsLoopback() {
-				continue
-			}
-			localIP = ip
-			break
-		}
+		localIP := k.interfaceAddrsFunc()
 		// Find endpoint matching IP to get service and namespace
 		endpointsList := k.APIConn.EndpointsList()
 
diff --git a/middleware/kubernetes/ns_test.go b/middleware/kubernetes/ns_test.go
index c7500a3fc..1aa4f910d 100644
--- a/middleware/kubernetes/ns_test.go
+++ b/middleware/kubernetes/ns_test.go
@@ -96,19 +96,13 @@ func (APIConnTest) EndpointsList() api.EndpointsList {
 
 func (APIConnTest) GetNodeByName(name string) (api.Node, error) { return api.Node{}, nil }
 
-type interfaceAddrsTest struct{}
-
-func (i interfaceAddrsTest) interfaceAddrs() ([]net.Addr, error) {
-	_, ipnet, _ := net.ParseCIDR("172.0.40.10/32")
-	return []net.Addr{ipnet}, nil
-}
-
 func TestDoCoreDNSRecord(t *testing.T) {
 
 	corednsRecord = dns.A{}
 	k := Kubernetes{Zones: []string{"inter.webs.test"}}
 
-	k.interfaceAddrs = &interfaceAddrsTest{}
+	k.interfaceAddrsFunc = func() net.IP { return net.ParseIP("172.0.40.10") }
+
 	k.APIConn = &APIConnTest{}
 
 	cdr := k.coreDNSRecord()
diff --git a/middleware/kubernetes/setup.go b/middleware/kubernetes/setup.go
index 08bc9b02d..a12673a13 100644
--- a/middleware/kubernetes/setup.go
+++ b/middleware/kubernetes/setup.go
@@ -56,10 +56,10 @@ func setup(c *caddy.Controller) error {
 
 func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 	k8s := &Kubernetes{
-		ResyncPeriod:   defaultResyncPeriod,
-		interfaceAddrs: &interfaceAddrs{},
-		PodMode:        PodModeDisabled,
-		Proxy:          proxy.Proxy{},
+		ResyncPeriod:       defaultResyncPeriod,
+		interfaceAddrsFunc: localPodIP,
+		PodMode:            PodModeDisabled,
+		Proxy:              proxy.Proxy{},
 	}
 
 	for c.Next() {