feat(.golangci.yml): enable gocritic and remediate

.golangci.yml

@@ -10,6 +10,7 @@ linters:
     - exportloopref
     - gochecknoinits
     - goconst
+    - gocritic
     - gofmt
     - goimports
     - misspell

pkg/cmd/kube-router.go

@@ -73,15 +73,16 @@ func (kr *KubeRouter) Run() error {
 	var err error
 	var ipsetMutex sync.Mutex
 	var wg sync.WaitGroup
-	healthChan := make(chan *healthcheck.ControllerHeartbeat, 10)
-	defer close(healthChan)
-	stopCh := make(chan struct{})
 
 	if !(kr.Config.RunFirewall || kr.Config.RunServiceProxy || kr.Config.RunRouter) {
 		klog.Info("Router, Firewall or Service proxy functionality must be specified. Exiting!")
 		os.Exit(0)
 	}
 
+	healthChan := make(chan *healthcheck.ControllerHeartbeat, 10)
+	defer close(healthChan)
+	stopCh := make(chan struct{})
+
 	hc, err := healthcheck.NewHealthController(kr.Config)
 	if err != nil {
 		return errors.New("Failed to create health controller: " + err.Error())
@@ -107,7 +108,7 @@ func (kr *KubeRouter) Run() error {
 	wg.Add(1)
 	go hc.RunCheck(healthChan, stopCh, &wg)
 
-	if kr.Config.MetricsPort > 0 {
+	if kr.Config.MetricsPort > 0 && kr.Config.MetricsPort < 65535 {
 		kr.Config.MetricsEnabled = true
 		mc, err := metrics.NewMetricsController(kr.Config)
 		if err != nil {
@@ -116,10 +117,8 @@ func (kr *KubeRouter) Run() error {
 		wg.Add(1)
 		go mc.Run(healthChan, stopCh, &wg)
 
-	} else if kr.Config.MetricsPort > 65535 {
-		klog.Errorf("Metrics port must be over 0 and under 65535, given port: %d", kr.Config.MetricsPort)
-		kr.Config.MetricsEnabled = false
 	} else {
+		klog.Errorf("Metrics port must be over 0 and under 65535, given port: %d", kr.Config.MetricsPort)
 		kr.Config.MetricsEnabled = false
 	}
 

pkg/controllers/netpol/network_policy_controller.go

@@ -581,7 +581,6 @@ func (npc *NetworkPolicyController) Cleanup() {
 		klog.Errorf("error encountered attempting to cleanup iptables rules: %v", err)
 		return
 	}
-	//klog.Infof("Final rules to save: %s", npc.filterTableRules)
 	// Restore (iptables-restore) npc's cleaned up version of the iptables filter chain
 	if err = utils.Restore("filter", npc.filterTableRules.Bytes()); err != nil {
 		klog.Errorf(

pkg/controllers/netpol/policy.go

@@ -415,11 +415,12 @@ func (npc *NetworkPolicyController) appendRuleToPolicyChain(policyChainName, com
 		}
 	}
 
+	// nolint:gocritic // we want to append to a separate array here so that we can re-use args below
 	markArgs := append(args, "-j", "MARK", "--set-xmark", "0x10000/0x10000", "\n")
 	npc.filterTableRules.WriteString(strings.Join(markArgs, " "))
 
-	returnArgs := append(args, "-m", "mark", "--mark", "0x10000/0x10000", "-j", "RETURN", "\n")
-	npc.filterTableRules.WriteString(strings.Join(returnArgs, " "))
+	args = append(args, "-m", "mark", "--mark", "0x10000/0x10000", "-j", "RETURN", "\n")
+	npc.filterTableRules.WriteString(strings.Join(args, " "))
 
 	return nil
 }
@@ -451,11 +452,12 @@ func (npc *NetworkPolicyController) buildNetworkPoliciesInfo() ([]networkPolicyI
 				egressType = true
 			}
 		}
-		if ingressType && egressType {
+		switch {
+		case ingressType && egressType:
 			newPolicy.policyType = kubeBothPolicyType
-		} else if egressType {
+		case egressType:
 			newPolicy.policyType = kubeEgressPolicyType
-		} else if ingressType {
+		case ingressType:
 			newPolicy.policyType = kubeIngressPolicyType
 		}
 
@@ -628,16 +630,15 @@ func (npc *NetworkPolicyController) processNetworkPolicyPorts(npPorts []networki
 		if npPort.Port == nil {
 			numericPorts = append(numericPorts, protocolAndPort{port: "", protocol: protocol})
 		} else if npPort.Port.Type == intstr.Int {
-			var portproto protocolAndPort
+			var portProto protocolAndPort
 			if npPort.EndPort != nil {
 				if *npPort.EndPort >= npPort.Port.IntVal {
-					portproto.endport = strconv.Itoa(int(*npPort.EndPort))
+					portProto.endport = strconv.Itoa(int(*npPort.EndPort))
 				}
 			}
-			portproto.protocol, portproto.port = protocol, npPort.Port.String()
-			numericPorts = append(numericPorts, portproto)
-		} else {
-			if protocol2eps, ok := namedPort2eps[npPort.Port.String()]; ok {
+			portProto.protocol, portProto.port = protocol, npPort.Port.String()
+			numericPorts = append(numericPorts, portProto)
+		} else if protocol2eps, ok := namedPort2eps[npPort.Port.String()]; ok {
 			if numericPort2eps, ok := protocol2eps[protocol]; ok {
 				for _, eps := range numericPort2eps {
 					namedPorts = append(namedPorts, *eps)
@@ -645,7 +646,6 @@ func (npc *NetworkPolicyController) processNetworkPolicyPorts(npPorts []networki
 			}
 		}
 	}
-	}
 	return
 }
 

pkg/controllers/proxy/network_service_graceful.go

@@ -102,13 +102,11 @@ func (nsc *NetworkServicesController) gracefulDeleteIpvsDestination(req graceful
 	aConn, iConn, err := nsc.getIpvsDestinationConnStats(req.ipvsSvc, req.ipvsDst)
 	if err != nil {
 		klog.V(1).Infof("Could not get connection stats for destination: %s", err.Error())
-	} else {
+	} else if aConn == 0 && iConn == 0 {
 		// Do we have active or inactive connections to this destination
 		// if we don't, proceed and delete the destination ahead of graceful period
-		if aConn == 0 && iConn == 0 {
 		deleteDestination = true
 	}
-	}
 
 	// Check if our destinations graceful termination period has passed
 	if time.Since(req.deletionTime) > req.gracefulTerminationPeriod {

pkg/controllers/proxy/network_services_controller.go

@@ -477,14 +477,14 @@ func (nsc *NetworkServicesController) doSync() error {
 }
 
 // Lookup service ip, protocol, port by given fwmark value (reverse of generateFwmark)
-func (nsc *NetworkServicesController) lookupServiceByFWMark(FWMark uint32) (string, string, int, error) {
+func (nsc *NetworkServicesController) lookupServiceByFwMark(fwMark uint32) (string, string, int, error) {
 	for _, svc := range nsc.serviceMap {
 		for _, externalIP := range svc.externalIPs {
 			gfwmark, err := generateFwmark(externalIP, svc.protocol, fmt.Sprint(svc.port))
 			if err != nil {
 				return "", "", 0, err
 			}
-			if FWMark == gfwmark {
+			if fwMark == gfwmark {
 				return externalIP, svc.protocol, svc.port, nil
 			}
 		}
@@ -762,7 +762,7 @@ func (nsc *NetworkServicesController) syncIpvsFirewall() error {
 			}
 			port = int(ipvsService.Port)
 		} else if ipvsService.FWMark != 0 {
-			address, protocol, port, err = nsc.lookupServiceByFWMark(ipvsService.FWMark)
+			address, protocol, port, err = nsc.lookupServiceByFwMark(ipvsService.FWMark)
 			if err != nil {
 				klog.Errorf("failed to lookup %d by FWMark: %s", ipvsService.FWMark, err)
 			}
@@ -888,7 +888,7 @@ func unsortedListsEquivalent(a, b []endpointsInfo) bool {
 		values[val] = 1
 	}
 	for _, val := range b {
-		values[val] = values[val] + 1
+		values[val]++
 	}
 
 	for _, val := range values {
@@ -1147,15 +1147,16 @@ func (nsc *NetworkServicesController) buildServicesInfo() serviceInfoMap {
 			svcInfo.scheduler = ipvs.RoundRobin
 			schedulingMethod, ok := svc.ObjectMeta.Annotations[svcSchedulerAnnotation]
 			if ok {
-				if schedulingMethod == ipvs.RoundRobin {
+				switch {
+				case schedulingMethod == ipvs.RoundRobin:
 					svcInfo.scheduler = ipvs.RoundRobin
-				} else if schedulingMethod == ipvs.LeastConnection {
+				case schedulingMethod == ipvs.LeastConnection:
 					svcInfo.scheduler = ipvs.LeastConnection
-				} else if schedulingMethod == ipvs.DestinationHashing {
+				case schedulingMethod == ipvs.DestinationHashing:
 					svcInfo.scheduler = ipvs.DestinationHashing
-				} else if schedulingMethod == ipvs.SourceHashing {
+				case schedulingMethod == ipvs.SourceHashing:
 					svcInfo.scheduler = ipvs.SourceHashing
-				} else if schedulingMethod == IpvsMaglevHashing {
+				case schedulingMethod == IpvsMaglevHashing:
 					svcInfo.scheduler = IpvsMaglevHashing
 				}
 			}
@@ -1579,27 +1580,27 @@ func ipvsServiceString(s *ipvs.Service) string {
 	}
 
 	if s.Flags&0x0001 != 0 {
-		flags = flags + "[persistent port]"
+		flags += "[persistent port]"
 	}
 
 	if s.Flags&0x0002 != 0 {
-		flags = flags + "[hashed entry]"
+		flags += "[hashed entry]"
 	}
 
 	if s.Flags&0x0004 != 0 {
-		flags = flags + "[one-packet scheduling]"
+		flags += "[one-packet scheduling]"
 	}
 
 	if s.Flags&0x0008 != 0 {
-		flags = flags + "[flag-1(fallback)]"
+		flags += "[flag-1(fallback)]"
 	}
 
 	if s.Flags&0x0010 != 0 {
-		flags = flags + "[flag-2(port)]"
+		flags += "[flag-2(port)]"
 	}
 
 	if s.Flags&0x0020 != 0 {
-		flags = flags + "[flag-3]"
+		flags += "[flag-3]"
 	}
 
 	return fmt.Sprintf("%s:%s:%v (Flags: %s)", protocol, s.Address, s.Port, flags)
@@ -1743,11 +1744,12 @@ func generateFwmark(ip, protocol, port string) (uint32, error) {
 func (ln *linuxNetworking) ipvsAddFWMarkService(vip net.IP, protocol, port uint16, persistent bool, persistentTimeout int32, scheduler string, flags schedFlags) (*ipvs.Service, error) {
 
 	var protocolStr string
-	if protocol == syscall.IPPROTO_TCP {
+	switch {
+	case protocol == syscall.IPPROTO_TCP:
 		protocolStr = tcpProtocol
-	} else if protocol == syscall.IPPROTO_UDP {
+	case protocol == syscall.IPPROTO_UDP:
 		protocolStr = udpProtocol
-	} else {
+	default:
 		protocolStr = "unknown"
 	}
 

pkg/controllers/proxy/service_endpoints_sync.go

@@ -517,11 +517,12 @@ func (nsc *NetworkServicesController) cleanupStaleIPVSConfig(activeServiceEndpoi
 			protocol = udpProtocol
 		}
 		var key string
-		if ipvsSvc.Address != nil {
+		switch {
+		case ipvsSvc.Address != nil:
 			key = generateIPPortID(ipvsSvc.Address.String(), protocol, strconv.Itoa(int(ipvsSvc.Port)))
-		} else if ipvsSvc.FWMark != 0 {
+		case ipvsSvc.FWMark != 0:
 			key = fmt.Sprint(ipvsSvc.FWMark)
-		} else {
+		default:
 			continue
 		}
 

pkg/controllers/routing/bgp_policies.go

@@ -336,6 +336,7 @@ func (nrc *NetworkRoutingController) addAllBGPPeersDefinedSet(iBGPPeerCIDRs, ext
 	if err != nil {
 		return err
 	}
+	// nolint:gocritic // We intentionally append to a different array here so as to not change the passed in externalBGPPeerCIDRs
 	allBgpPeers := append(externalBGPPeerCIDRs, iBGPPeerCIDRs...)
 	if currentDefinedSet == nil {
 		allPeerNS := &gobgpapi.DefinedSet{

pkg/controllers/routing/network_routes_controller.go

@@ -570,7 +570,8 @@ func (nrc *NetworkRoutingController) injectRoute(path *gobgpapi.Path) error {
 		nrc.cleanupTunnel(dst, tunnelName)
 	}
 
-	if link != nil {
+	switch {
+	case link != nil:
 		// if we setup an overlay tunnel link, then use it for destination routing
 		route = &netlink.Route{
 			LinkIndex: link.Attrs().Index,
@@ -578,7 +579,7 @@ func (nrc *NetworkRoutingController) injectRoute(path *gobgpapi.Path) error {
 			Dst:       dst,
 			Protocol:  0x11,
 		}
-	} else if sameSubnet {
+	case sameSubnet:
 		// if the nextHop is within the same subnet, add a route for the destination so that traffic can bet routed
 		// at layer 2 and minimize the need to traverse a router
 		route = &netlink.Route{
@@ -586,7 +587,7 @@ func (nrc *NetworkRoutingController) injectRoute(path *gobgpapi.Path) error {
 			Gw:       nextHop,
 			Protocol: 0x11,
 		}
-	} else {
+	default:
 		// otherwise, let BGP do its thing, nothing to do here
 		return nil
 	}

pkg/controllers/routing/network_routes_controller_test.go

@@ -1646,7 +1646,6 @@ func Test_routeReflectorConfiguration(t *testing.T) {
 					Name: "node-1",
 					Annotations: map[string]string{
 						"kube-router.io/node.asn": "100",
-						//rrServerAnnotation:        "10_0_0_1",
 						rrServerAnnotation:        "hello world",
 					},
 				},
@@ -1712,11 +1711,9 @@ func Test_routeReflectorConfiguration(t *testing.T) {
 				if testcase.expectedClusterID != testcase.nrc.bgpClusterID {
 					t.Errorf("Node suppose to have cluster id '%s' but got %s", testcase.expectedClusterID, testcase.nrc.bgpClusterID)
 				}
-			} else {
-				if err == nil {
+			} else if err == nil {
 				t.Fatal("misconfigured BGP server not suppose to start")
 			}
-			}
 		})
 	}
 

pkg/controllers/routing/utils.go

@@ -119,7 +119,7 @@ func getNodeSubnet(nodeIP net.IP) (net.IPNet, string, error) {
 // is greater than 12 (after removing "."), then the interface name is tunXYZ
 // as opposed to tun-XYZ
 func generateTunnelName(nodeIP string) string {
-	hash := strings.Replace(nodeIP, ".", "", -1)
+	hash := strings.ReplaceAll(nodeIP, ".", "")
 
 	if len(hash) < 12 {
 		return "tun-" + hash
@@ -162,6 +162,7 @@ func parseBGPNextHop(path *gobgpapi.Path) (net.IP, error) {
 		if err := ptypes.UnmarshalAny(pAttr, &value); err != nil {
 			return nil, fmt.Errorf("failed to unmarshal path attribute: %s", err)
 		}
+		// nolint:gocritic // We can't change this to an if condition because it is a .(type) expression
 		switch a := value.Message.(type) {
 		case *gobgpapi.NextHopAttribute:
 			nextHop := net.ParseIP(a.NextHop).To4()

pkg/healthcheck/health_controller.go

@@ -156,8 +156,6 @@ func (hc *HealthController) RunServer(stopCh <-chan struct{}, wg *sync.WaitGroup
 				klog.Errorf("Health controller error: %s", err)
 			}
 		}()
-	} else if hc.Config.MetricsPort > 65535 {
-		klog.Errorf("Metrics port must be over 0 and under 65535, given port: %d", hc.Config.MetricsPort)
 	} else {
 		hc.HTTPEnabled = false
 	}