controller: - Replace panics with errors

- Add context to errors for debugging
            - Refactor init() code so ipset isn't required to run
              "kube-router --help" for example

app/controllers/network_policy_controller.go

@@ -92,7 +92,10 @@ func (npc *NetworkPolicyController) Run(stopCh <-chan struct{}, wg *sync.WaitGro
 
 		if watchers.PodWatcher.HasSynced() && watchers.NetworkPolicyWatcher.HasSynced() {
 			glog.Infof("Performing periodic syn of the iptables to reflect network policies")
-			npc.Sync()
+			err := npc.Sync()
+			if err != nil {
+				glog.Errorf("Error during periodic sync: ", err)
+			}
 		} else {
 			continue
 		}
@@ -109,7 +112,10 @@ func (npc *NetworkPolicyController) Run(stopCh <-chan struct{}, wg *sync.WaitGro
 func (npc *NetworkPolicyController) OnPodUpdate(podUpdate *watchers.PodUpdate) {
 	glog.Infof("Received pod update namspace:%s pod name:%s", podUpdate.Pod.Namespace, podUpdate.Pod.Name)
 	if watchers.PodWatcher.HasSynced() && watchers.NetworkPolicyWatcher.HasSynced() {
-		npc.Sync()
+		err := npc.Sync()
+		if err != nil {
+			glog.Errorf("Error syncing on pod update: ", err)
+		}
 	} else {
 		glog.Infof("Received pod update, but controller not in sync")
 	}
@@ -118,7 +124,10 @@ func (npc *NetworkPolicyController) OnPodUpdate(podUpdate *watchers.PodUpdate) {
 func (npc *NetworkPolicyController) OnNetworkPolicyUpdate(networkPolicyUpdate *watchers.NetworkPolicyUpdate) {
 	glog.Infof("Received network policy update namspace:%s policy name:%s", networkPolicyUpdate.NetworkPolicy.Namespace, networkPolicyUpdate.NetworkPolicy.Name)
 	if watchers.PodWatcher.HasSynced() && watchers.NetworkPolicyWatcher.HasSynced() {
-		npc.Sync()
+		err := npc.Sync()
+		if err != nil {
+			glog.Errorf("Error syncing on network policy update: ", err)
+		}
 	} else {
 		glog.Infof("Received network policy update, but controller not in sync")
 	}
@@ -127,19 +136,27 @@ func (npc *NetworkPolicyController) OnNetworkPolicyUpdate(networkPolicyUpdate *w
 func (npc *NetworkPolicyController) OnNamespaceUpdate(namespaceUpdate *watchers.NamespaceUpdate) {
 	glog.Infof("Received namesapce update namspace:%s", namespaceUpdate.Namespace.Name)
 	if watchers.PodWatcher.HasSynced() && watchers.NetworkPolicyWatcher.HasSynced() {
-		npc.Sync()
+		err := npc.Sync()
+		if err != nil {
+			glog.Errorf("Error syncing on namespace update: ", err)
+		}
 	} else {
 		glog.Infof("Received namspace update, but controller not in sync")
 	}
 }
 
 // Sync synchronizes iptables to desired state of network policies
-func (npc *NetworkPolicyController) Sync() {
+func (npc *NetworkPolicyController) Sync() error {
 
 	var err error
 	npc.mu.Lock()
 	defer npc.mu.Unlock()
 
+	_, err = exec.LookPath("ipset")
+	if err != nil {
+		return errors.New("Ensure ipset package is installed: " + err.Error())
+	}
+
 	start := time.Now()
 	defer func() {
 		glog.Infof("sync iptables took %v", time.Since(start))
@@ -147,27 +164,25 @@ func (npc *NetworkPolicyController) Sync() {
 
 	npc.networkPoliciesInfo, err = buildNetworkPoliciesInfo()
 	if err != nil {
-		glog.Errorf("Aborting sync. Failed to build network policies: %s", err.Error())
-		return
+		return errors.New("Aborting sync. Failed to build network policies: %s" + err.Error())
 	}
 
 	activePolicyChains, err := npc.syncNetworkPolicyChains()
 	if err != nil {
-		glog.Errorf("Aborting sync. Failed to sync network policy chains: %s", err.Error())
-		return
+		return errors.New("Aborting sync. Failed to sync network policy chains: %s" + err.Error())
 	}
 
 	activePodFwChains, err := npc.syncPodFirewallChains()
 	if err != nil {
-		glog.Errorf("Aborting sync. Failed to sync pod firewalls: %s", err.Error())
-		return
+		return errors.New("Aborting sync. Failed to sync pod firewalls: %s" + err.Error())
 	}
 
 	err = cleanupStaleRules(activePolicyChains, activePodFwChains)
 	if err != nil {
-		glog.Errorf("Aborting sync. Failed to cleanup stale iptable rules: %s", err.Error())
-		return
+		return errors.New("Aborting sync. Failed to cleanup stale iptable rules: %s" + err.Error())
 	}
+
+	return nil
 }
 
 // Configure iptable rules representing each network policy. All pod's matched by
@@ -763,13 +778,6 @@ func (npc *NetworkPolicyController) Cleanup() {
 	glog.Infof("Successfully cleaned the iptables configuration done by kube-router")
 }
 
-func init() {
-	_, err := exec.LookPath("ipset")
-	if err != nil {
-		panic("ipset command not found ensure ipset package is installed")
-	}
-}
-
 func NewNetworkPolicyController(clientset *kubernetes.Clientset, config *options.KubeRouterConfig) (*NetworkPolicyController, error) {
 
 	npc := NetworkPolicyController{}
@@ -778,14 +786,14 @@ func NewNetworkPolicyController(clientset *kubernetes.Clientset, config *options
 
 	node, err := utils.GetNodeObject(clientset, config.HostnameOverride)
 	if err != nil {
-		panic(err.Error())
+		return nil, err
 	}
 
 	npc.nodeHostName = node.Name
 
 	nodeIP, err := getNodeIP(node)
 	if err != nil {
-		panic(err.Error())
+		return nil, err
 	}
 	npc.nodeIP = nodeIP
 

app/controllers/network_routes_controller.go

@@ -1,6 +1,7 @@
 package controllers
 
 import (
+	"errors"
 	"fmt"
 	"net"
 	"strconv"
@@ -85,15 +86,17 @@ func (nrc *NetworkRoutingController) Run(stopCh <-chan struct{}, wg *sync.WaitGr
 
 	// Wait till we are ready to launch BGP server
 	for {
-		ok := nrc.startBgpServer()
-		if !ok {
+		err := nrc.startBgpServer()
+		if err != nil {
+			glog.Errorf("Failed to start node BGP server: %s", err)
 			select {
 			case <-stopCh:
 				glog.Infof("Shutting down network routes controller")
 				return
 			case <-t.C:
+				glog.Infof("Retrying start of node BGP server")
+				continue
 			}
-			continue
 		} else {
 			break
 		}
@@ -348,12 +351,12 @@ func (nrc *NetworkRoutingController) OnNodeUpdate(nodeUpdate *watchers.NodeUpdat
 	}
 }
 
-func (nrc *NetworkRoutingController) startBgpServer() bool {
+func (nrc *NetworkRoutingController) startBgpServer() error {
 
 	var nodeAsnNumber uint32
 	node, err := utils.GetNodeObject(nrc.clientset, nrc.hostnameOverride)
 	if err != nil {
-		panic("Failed to get node object from api server due to " + err.Error())
+		return errors.New("Failed to get node object from api server: " + err.Error())
 	}
 
 	if nrc.bgpFullMeshMode {
@@ -361,14 +364,12 @@ func (nrc *NetworkRoutingController) startBgpServer() bool {
 	} else {
 		nodeasn, ok := node.ObjectMeta.Annotations["net.kuberouter.nodeasn"]
 		if !ok {
-			glog.Infof("Could not find ASN number for the node. Node need to be annotated with ASN number details to start BGP server.")
-			return false
+			return errors.New("Could not find ASN number for the node. Node need to be annotated with ASN number details to start BGP server.")
 		} else {
 			glog.Infof("Found ASN for the node to be %s from the node annotations", nodeasn)
 			asnNo, err := strconv.ParseUint(nodeasn, 0, 32)
 			if err != nil {
-				glog.Errorf("Failed to parse ASN number specified for the the node")
-				return false
+				return errors.New("Failed to parse ASN number specified for the the node")
 			}
 			nodeAsnNumber = uint32(asnNo)
 		}
@@ -389,7 +390,7 @@ func (nrc *NetworkRoutingController) startBgpServer() bool {
 	}
 
 	if err := nrc.bgpServer.Start(global); err != nil {
-		panic("Failed to start BGP server due to : " + err.Error())
+		return errors.New("Failed to start BGP server due to : " + err.Error())
 	}
 
 	go nrc.watchBgpUpdates()
@@ -405,38 +406,38 @@ func (nrc *NetworkRoutingController) startBgpServer() bool {
 				},
 			}
 			if err := nrc.bgpServer.AddNeighbor(n); err != nil {
-				panic("Failed to peer with global peer router due to: " + peer)
+				return errors.New("Failed to peer with global peer router \"" + peer + "\" due to: " + err.Error())
 			}
 		}
 	} else {
 		nodeBgpPeerAsn, ok := node.ObjectMeta.Annotations["net.kuberouter.node.bgppeer.asn"]
 		if !ok {
 			glog.Infof("Could not find BGP peer info for the node in the node annotations so skipping configuring peer.")
-			return true
+			return nil
 		}
 		asnNo, err := strconv.ParseUint(nodeBgpPeerAsn, 0, 32)
 		if err != nil {
-			panic("Failed to parse ASN number specified for the the node in the annotations")
+			return errors.New("Failed to parse ASN number specified for the the node in the annotations")
 		}
 		peerAsnNo := uint32(asnNo)
 
 		nodeBgpPeersAnnotation, ok := node.ObjectMeta.Annotations["net.kuberouter.node.bgppeer.address"]
 		if !ok {
 			glog.Infof("Could not find BGP peer info for the node in the node annotations so skipping configuring peer.")
-			return true
+			return nil
 		}
 		nodePeerRouters := make([]string, 0)
 		if strings.Contains(nodeBgpPeersAnnotation, ",") {
 			ips := strings.Split(nodeBgpPeersAnnotation, ",")
 			for _, ip := range ips {
 				if net.ParseIP(ip) == nil {
-					panic("Invalid node BGP peer router ip in the annotation: " + ip)
+					return errors.New("Invalid node BGP peer router ip in the annotation: " + ip)
 				}
 			}
 			nodePeerRouters = append(nodePeerRouters, ips...)
 		} else {
 			if net.ParseIP(nodeBgpPeersAnnotation) == nil {
-				panic("Invalid node BGP peer router ip: " + nodeBgpPeersAnnotation)
+				return errors.New("Invalid node BGP peer router ip: " + nodeBgpPeersAnnotation)
 			}
 			nodePeerRouters = append(nodePeerRouters, nodeBgpPeersAnnotation)
 		}
@@ -449,14 +450,14 @@ func (nrc *NetworkRoutingController) startBgpServer() bool {
 				},
 			}
 			if err := nrc.bgpServer.AddNeighbor(n); err != nil {
-				panic("Failed to peer with node specific BGP peer router: " + peer + " due to " + err.Error())
+				return errors.New("Failed to peer with node specific BGP peer router: " + peer + " due to " + err.Error())
 			}
 		}
 
 		glog.Infof("Successfully configured  %s in ASN %v as BGP peer to the node", nodeBgpPeersAnnotation, peerAsnNo)
 	}
 
-	return true
+	return nil
 }
 
 func NewNetworkRoutingController(clientset *kubernetes.Clientset, kubeRouterConfig *options.KubeRouterConfig) (*NetworkRoutingController, error) {
@@ -471,10 +472,10 @@ func NewNetworkRoutingController(clientset *kubernetes.Clientset, kubeRouterConf
 	if len(kubeRouterConfig.ClusterAsn) != 0 {
 		asn, err := strconv.ParseUint(kubeRouterConfig.ClusterAsn, 0, 32)
 		if err != nil {
-			panic("Invalid cluster ASN: " + err.Error())
+			return nil, errors.New("Invalid cluster ASN: " + err.Error())
 		}
 		if asn > 65534 || asn < 64512 {
-			panic("Invalid ASN number for cluster ASN")
+			return nil, errors.New("Invalid ASN number for cluster ASN")
 		}
 		nrc.defaultNodeAsnNumber = uint32(asn)
 	} else {
@@ -485,7 +486,7 @@ func NewNetworkRoutingController(clientset *kubernetes.Clientset, kubeRouterConf
 
 	if (len(kubeRouterConfig.PeerRouter) != 0 && len(kubeRouterConfig.PeerAsn) == 0) ||
 		(len(kubeRouterConfig.PeerRouter) == 0 && len(kubeRouterConfig.PeerAsn) != 0) {
-		panic("Either both or none of the params --peer-asn, --peer-router must be specified")
+		return nil, errors.New("Either both or none of the params --peer-asn, --peer-router must be specified")
 	}
 
 	if len(kubeRouterConfig.PeerRouter) != 0 && len(kubeRouterConfig.PeerAsn) != 0 {
@@ -494,24 +495,24 @@ func NewNetworkRoutingController(clientset *kubernetes.Clientset, kubeRouterConf
 			ips := strings.Split(kubeRouterConfig.PeerRouter, ",")
 			for _, ip := range ips {
 				if net.ParseIP(ip) == nil {
-					panic("Invalid global BGP peer router ip: " + kubeRouterConfig.PeerRouter)
+					return nil, errors.New("Invalid global BGP peer router ip: " + kubeRouterConfig.PeerRouter)
 				}
 			}
 			nrc.globalPeerRouters = append(nrc.globalPeerRouters, ips...)
 
 		} else {
 			if net.ParseIP(kubeRouterConfig.PeerRouter) == nil {
-				panic("Invalid global BGP peer router ip: " + kubeRouterConfig.PeerRouter)
+				return nil, errors.New("Invalid global BGP peer router ip: " + kubeRouterConfig.PeerRouter)
 			}
 			nrc.globalPeerRouters = append(nrc.globalPeerRouters, kubeRouterConfig.PeerRouter)
 		}
 
 		asn, err := strconv.ParseUint(kubeRouterConfig.PeerAsn, 0, 32)
 		if err != nil {
-			panic("Invalid global BGP peer ASN: " + err.Error())
+			return nil, errors.New("Invalid global BGP peer ASN: " + err.Error())
 		}
 		if asn > 65534 {
-			panic("Invalid ASN number for global BGP peer")
+			return nil, errors.New("Invalid ASN number for global BGP peer")
 		}
 		nrc.globalPeerAsnNumber = uint32(asn)
 	}
@@ -519,14 +520,14 @@ func NewNetworkRoutingController(clientset *kubernetes.Clientset, kubeRouterConf
 	nrc.hostnameOverride = kubeRouterConfig.HostnameOverride
 	node, err := utils.GetNodeObject(clientset, nrc.hostnameOverride)
 	if err != nil {
-		panic(err.Error())
+		return nil, errors.New("Failed getting node object from API server: " + err.Error())
 	}
 
 	nrc.nodeHostName = node.Name
 
 	nodeIP, err := getNodeIP(node)
 	if err != nil {
-		panic(err.Error())
+		return nil, errors.New("Failed getting IP address from node object: " + err.Error())
 	}
 	nrc.nodeIP = nodeIP
 

app/controllers/network_services_controller.go

@@ -74,7 +74,7 @@ type endpointsInfo struct {
 type endpointsInfoMap map[string][]endpointsInfo
 
 // periodically sync ipvs configuration to reflect desired state of services and endpoints
-func (nsc *NetworkServicesController) Run(stopCh <-chan struct{}, wg *sync.WaitGroup) {
+func (nsc *NetworkServicesController) Run(stopCh <-chan struct{}, wg *sync.WaitGroup) error {
 
 	t := time.NewTicker(nsc.syncPeriod)
 	defer t.Stop()
@@ -85,13 +85,13 @@ func (nsc *NetworkServicesController) Run(stopCh <-chan struct{}, wg *sync.WaitG
 	// enable masquerade rule
 	err := ensureMasqueradeIptablesRule(nsc.masqueradeAll, nsc.podCidr)
 	if err != nil {
-		panic("Failed to do add masqurade rule in POSTROUTING chain of nat table due to: %s" + err.Error())
+		return errors.New("Failed to do add masqurade rule in POSTROUTING chain of nat table due to: %s" + err.Error())
 	}
 
 	// enable ipvs connection tracking
 	err = ensureIpvsConntrack()
 	if err != nil {
-		panic("Failed to do sysctl net.ipv4.vs.conntrack=1 due to: %s" + err.Error())
+		return errors.New("Failed to do sysctl net.ipv4.vs.conntrack=1 due to: %s" + err.Error())
 	}
 
 	// loop forever unitl notified to stop on stopCh
@@ -99,7 +99,7 @@ func (nsc *NetworkServicesController) Run(stopCh <-chan struct{}, wg *sync.WaitG
 		select {
 		case <-stopCh:
 			glog.Infof("Shutting down network services controller")
-			return
+			return nil
 		default:
 		}
 
@@ -113,7 +113,7 @@ func (nsc *NetworkServicesController) Run(stopCh <-chan struct{}, wg *sync.WaitG
 		select {
 		case <-stopCh:
 			glog.Infof("Shutting down network services controller")
-			return
+			return nil
 		case <-t.C:
 		}
 	}
@@ -174,14 +174,17 @@ func (nsc *NetworkServicesController) OnServiceUpdate(serviceUpdate *watchers.Se
 
 // sync the ipvs service and server details configured to reflect the desired state of services and endpoint
 // as learned from services and endpoints information from the api server
-func (nsc *NetworkServicesController) syncIpvsServices(serviceInfoMap serviceInfoMap, endpointsInfoMap endpointsInfoMap) {
+func (nsc *NetworkServicesController) syncIpvsServices(serviceInfoMap serviceInfoMap, endpointsInfoMap endpointsInfoMap) error {
 
 	start := time.Now()
 	defer func() {
 		glog.Infof("sync ipvs servers took %v", time.Since(start))
 	}()
 
-	dummyVipInterface := getKubeDummyInterface()
+	dummyVipInterface, err := getKubeDummyInterface()
+	if err != nil {
+		return errors.New("Failed creating dummy interface: " + err.Error())
+	}
 
 	// map of active services and service endpoints
 	activeServiceEndpointMap := make(map[string][]string)
@@ -253,7 +256,7 @@ func (nsc *NetworkServicesController) syncIpvsServices(serviceInfoMap serviceInf
 	glog.Infof("Cleaning up if any, old ipvs service and servers which are no longer needed")
 	ipvsSvcs, err := h.ListServices()
 	if err != nil {
-		panic(err)
+		return errors.New("Failed to list IPVS services: " + err.Error())
 	}
 	for _, ipvsSvc := range ipvsSvcs {
 		key := generateIpPortId(ipvsSvc.Address.String(), ipvsSvc.Protocol.String(), strconv.Itoa(int(ipvsSvc.Port)))
@@ -290,6 +293,7 @@ func (nsc *NetworkServicesController) syncIpvsServices(serviceInfoMap serviceInf
 		}
 	}
 	glog.Infof("IPVS servers and services are synced to desired state!!")
+	return nil
 }
 
 func buildServicesInfo() serviceInfoMap {
@@ -394,7 +398,7 @@ func deleteMasqueradeIptablesRule() error {
 func ipvsAddService(vip net.IP, protocol, port uint16, persistent bool) (*libipvs.Service, error) {
 	svcs, err := h.ListServices()
 	if err != nil {
-		panic(err)
+		return nil, err
 	}
 	for _, svc := range svcs {
 		if strings.Compare(vip.String(), svc.Address.String()) == 0 &&
@@ -455,22 +459,22 @@ func generateIpPortId(ip, protocol, port string) string {
 	return ip + "-" + protocol + "-" + port
 }
 
-func getKubeDummyInterface() netlink.Link {
+func getKubeDummyInterface() (netlink.Link, error) {
 	var dummyVipInterface netlink.Link
 	dummyVipInterface, err := netlink.LinkByName(KUBE_DUMMY_IF)
 	if err != nil && err.Error() == IFACE_NOT_FOUND {
 		glog.Infof("Could not find dummy interface: " + KUBE_DUMMY_IF + " to assign cluster ip's, so creating one")
 		err = netlink.LinkAdd(&netlink.Dummy{netlink.LinkAttrs{Name: KUBE_DUMMY_IF}})
 		if err != nil {
-			panic("Failed to add dummy interface:  " + err.Error())
+			return nil, errors.New("Failed to add dummy interface:  " + err.Error())
 		}
 		dummyVipInterface, err = netlink.LinkByName(KUBE_DUMMY_IF)
 		err = netlink.LinkSetUp(dummyVipInterface)
 		if err != nil {
-			panic("Failed to bring dummy interface up: " + err.Error())
+			return nil, errors.New("Failed to bring dummy interface up: " + err.Error())
 		}
 	}
-	return dummyVipInterface
+	return dummyVipInterface, nil
 }
 
 // clean up all the configurations (IPVS, iptables, links)
@@ -511,7 +515,7 @@ func NewNetworkServicesController(clientset *kubernetes.Clientset, config *optio
 
 	handle, err := libipvs.New()
 	if err != nil {
-		panic(err)
+		return nil, err
 	}
 	h = handle
 
@@ -537,13 +541,13 @@ func NewNetworkServicesController(clientset *kubernetes.Clientset, config *optio
 
 	node, err := utils.GetNodeObject(clientset, config.HostnameOverride)
 	if err != nil {
-		panic(err.Error())
+		return nil, err
 	}
 
 	nsc.nodeHostName = node.Name
 	nodeIP, err := getNodeIP(node)
 	if err != nil {
-		panic(err.Error())
+		return nil, err
 	}
 	nsc.nodeIP = nodeIP