Handle both cases where node can be registered with master either

by host name or FQDN. kubelet can be started with --hostname-override with configurable value.
In AWS envirinment typcally its set FQDN obtained from the metda data. This fix ensures
we can deploy kube-router in case nodes are registered with FQDN

Fixes #17

Author: Murali Reddy

app/controllers/network_policy_controller.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/cloudnativelabs/kube-router/app/options"
 	"github.com/cloudnativelabs/kube-router/app/watchers"
+	"github.com/cloudnativelabs/kube-router/utils"
 	"github.com/coreos/go-iptables/iptables"
 	"github.com/golang/glog"
 	"github.com/janeczku/go-ipset/ipset"
@@ -775,12 +776,19 @@ func NewNetworkPolicyController(clientset *kubernetes.Clientset, config *options
 	if err != nil {
 		panic(err.Error())
 	}
-	npc.nodeHostName = nodeHostName
+	nodeFqdnHostName := utils.GetFqdn()
 
 	node, err := clientset.Core().Nodes().Get(nodeHostName, metav1.GetOptions{})
 	if err != nil {
-		panic(err.Error())
+		node, err = clientset.Core().Nodes().Get(nodeFqdnHostName, metav1.GetOptions{})
+		if err != nil {
+			panic(err.Error())
+		}
+		npc.nodeHostName = nodeFqdnHostName
+	} else {
+		npc.nodeHostName = nodeHostName
 	}
+
 	nodeIP, err := getNodeIP(node)
 	if err != nil {
 		panic(err.Error())

app/controllers/network_routes_controller.go

@@ -258,12 +258,19 @@ func NewNetworkRoutingController(clientset *kubernetes.Clientset, kubeRouterConf
 	if err != nil {
 		panic(err.Error())
 	}
-	nrc.nodeHostName = nodeHostName
+	nodeFqdnHostName := utils.GetFqdn()
 
 	node, err := clientset.Core().Nodes().Get(nodeHostName, metav1.GetOptions{})
 	if err != nil {
-		panic(err.Error())
+		node, err = clientset.Core().Nodes().Get(nodeFqdnHostName, metav1.GetOptions{})
+		if err != nil {
+			panic(err.Error())
+		}
+		nrc.nodeHostName = nodeFqdnHostName
+	} else {
+		nrc.nodeHostName = nodeHostName
 	}
+
 	nodeIP, err := getNodeIP(node)
 	if err != nil {
 		panic(err.Error())

app/controllers/network_services_controller.go

@@ -547,11 +547,17 @@ func NewNetworkServicesController(clientset *kubernetes.Clientset, config *optio
 	if err != nil {
 		panic(err.Error())
 	}
-	nsc.nodeHostName = nodeHostName
+	nodeFqdnHostName := utils.GetFqdn()
 
 	node, err := clientset.Core().Nodes().Get(nodeHostName, v1.GetOptions{})
 	if err != nil {
-		panic(err.Error())
+		node, err = clientset.Core().Nodes().Get(nodeFqdnHostName, v1.GetOptions{})
+		if err != nil {
+			panic(err.Error())
+		}
+		nsc.nodeHostName = nodeFqdnHostName
+	} else {
+		nsc.nodeHostName = nodeHostName
 	}
 	nodeIP, err := getNodeIP(node)
 	if err != nil {

utils/fqdn.go

@@ -0,0 +1,16 @@
+package utils
+
+import (
+	"bytes"
+	"os/exec"
+)
+
+func GetFqdn() string {
+	cmd := exec.Command("hostname", "-f")
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	cmd.Run()
+	fqdn := out.String()
+	fqdn = fqdn[:len(fqdn)-1]
+	return fqdn
+}