Fix linter findings

- always start error messages with a non-capital charachter (error
  messages are stacked)
- when returnig (foo, error), error should always be last

Author: damyan

metalbond.go

@@ -69,7 +69,7 @@ func (m *MetalBond) AddPeer(addr, localIP string) error {
 
 	m.log().Infof("Adding peer %s", addr)
 	if _, exists := m.peers[addr]; exists {
-		return fmt.Errorf("Peer already registered")
+		return fmt.Errorf("peer already registered")
 	}
 
 	m.peers[addr] = newMetalBondPeer(
@@ -114,7 +114,7 @@ func (m *MetalBond) PeerState(addr string) (ConnectionState, error) {
 		state := m.peers[addr].GetState()
 		return state, nil
 	} else {
-		return CLOSED, fmt.Errorf("Peer %s does not exist", addr)
+		return CLOSED, fmt.Errorf("peer %s does not exist", addr)
 	}
 }
 
@@ -126,14 +126,14 @@ func (m *MetalBond) Subscribe(vni VNI) error {
 	}()
 
 	if _, exists := m.mySubscriptions[vni]; exists {
-		return fmt.Errorf("Already subscribed to VNI %d", vni)
+		return fmt.Errorf("already subscribed to VNI %d", vni)
 	}
 
 	m.mySubscriptions[vni] = true
 
 	for _, p := range m.peers {
 		if err := p.Subscribe(vni); err != nil {
-			return fmt.Errorf("Could not subscribe to vni %d: %v", vni, err)
+			return fmt.Errorf("could not subscribe to vni %d: %v", vni, err)
 		}
 	}
 
@@ -156,7 +156,7 @@ func (m *MetalBond) Unsubscribe(vni VNI) error {
 	defer m.mtxMySubscriptions.Unlock()
 
 	if _, exists := m.mySubscriptions[vni]; !exists {
-		return fmt.Errorf("Already unsubscribed from VNI %d", vni)
+		return fmt.Errorf("already unsubscribed from VNI %d", vni)
 	}
 
 	for _, p := range m.peers {
@@ -168,7 +168,7 @@ func (m *MetalBond) Unsubscribe(vni VNI) error {
 		for dest, nhs := range m.routeTable.GetDestinationsByVNI(vni) {
 			for _, nh := range nhs {
 				if m.routeTable.NextHopExists(vni, dest, nh, p) {
-					if err, _ := m.routeTable.RemoveNextHop(vni, dest, nh, p); err != nil {
+					if _, err := m.routeTable.RemoveNextHop(vni, dest, nh, p); err != nil {
 						p.log().Errorf("Could not remove received route from peer's receivedRoutes Table: %v", err)
 					}
 				}
@@ -189,7 +189,7 @@ func (m *MetalBond) AnnounceRoute(vni VNI, dest Destination, hop NextHop) error
 	m.log().Infof("Announcing VNI %d: %s via %s", vni, dest, hop)
 
 	if err := m.myAnnouncements.AddNextHop(vni, dest, hop, nil); err != nil {
-		return fmt.Errorf("Cannot announce route: %v", err)
+		return fmt.Errorf("cannot announce route: %v", err)
 	}
 
 	if err := m.distributeRouteToPeers(ADD, vni, dest, hop, nil); err != nil {
@@ -203,7 +203,7 @@ func (m *MetalBond) WithdrawRoute(vni VNI, dest Destination, hop NextHop) error
 
 	m.log().Infof("withdraw a route for VNI %d: %s via %s", vni, dest, hop)
 
-	err, remaining := m.myAnnouncements.RemoveNextHop(vni, dest, hop, nil)
+	remaining, err := m.myAnnouncements.RemoveNextHop(vni, dest, hop, nil)
 	if err != nil {
 		return fmt.Errorf("cannot remove route from the local announcement route table: %v", err)
 	}
@@ -334,7 +334,7 @@ func (m *MetalBond) addReceivedRoute(fromPeer *metalBondPeer, vni VNI, dest Dest
 }
 
 func (m *MetalBond) removeReceivedRoute(fromPeer *metalBondPeer, vni VNI, dest Destination, hop NextHop) error {
-	err, remaining := m.routeTable.RemoveNextHop(vni, dest, hop, fromPeer)
+	remaining, err := m.routeTable.RemoveNextHop(vni, dest, hop, fromPeer)
 	if err != nil {
 		return fmt.Errorf("Cannot remove route from route table: %v", err)
 	}
@@ -370,7 +370,7 @@ func (m *MetalBond) addSubscriber(peer *metalBondPeer, vni VNI) error {
 	}
 
 	if _, exists := m.subscribers[vni][peer]; exists {
-		return fmt.Errorf("Peer is already subscribed!")
+		return fmt.Errorf("peer is already subscribed")
 	}
 
 	m.subscribers[vni][peer] = true
@@ -410,20 +410,20 @@ func (m *MetalBond) removeSubscriber(peer *metalBondPeer, vni VNI) error {
 	m.mtxSubscribers.RLock()
 	if _, exists := m.subscribers[vni]; !exists {
 		m.mtxSubscribers.RUnlock()
-		return fmt.Errorf("Peer is not subscribed!")
+		return fmt.Errorf("peer is not subscribed")
 	}
 
 	if _, exists := m.subscribers[vni][peer]; !exists {
 		m.mtxSubscribers.RUnlock()
-		return fmt.Errorf("Peer is not subscribed!")
+		return fmt.Errorf("peer is not subscribed")
 	}
 	m.mtxSubscribers.RUnlock()
 
 	// remove routes from peer and local and distribute the remove
 	peer.log().Infof("Removing all received nexthops from peer for vni %d", vni)
 	for dest, nhs := range peer.receivedRoutes.GetDestinationsByVNI(vni) {
 		for _, nh := range nhs {
-			if err, _ := peer.receivedRoutes.RemoveNextHop(vni, dest, nh, peer); err != nil {
+			if _, err := peer.receivedRoutes.RemoveNextHop(vni, dest, nh, peer); err != nil {
 				peer.log().Errorf("Could not remove received route from peer's receivedRoutes Table: %v", err)
 			}
 

peer.go

@@ -117,7 +117,7 @@ func (p *metalBondPeer) Unsubscribe(vni VNI) error {
 
 	for dest, nhs := range p.receivedRoutes.GetDestinationsByVNI(vni) {
 		for _, nh := range nhs {
-			err, _ := p.receivedRoutes.RemoveNextHop(vni, dest, nh, p)
+			_, err := p.receivedRoutes.RemoveNextHop(vni, dest, nh, p)
 			if err != nil {
 				p.log().Errorf("Could not remove received route from peer's receivedRoutes Table: %v", err)
 			}
@@ -230,7 +230,7 @@ func (p *metalBondPeer) cleanup() {
 	for _, vni := range p.receivedRoutes.GetVNIs() {
 		for dest, nhs := range p.receivedRoutes.GetDestinationsByVNI(vni) {
 			for _, nh := range nhs {
-				err, _ := p.receivedRoutes.RemoveNextHop(vni, dest, nh, p)
+				_, err := p.receivedRoutes.RemoveNextHop(vni, dest, nh, p)
 				if err != nil {
 					p.log().Errorf("Could not remove received route from peer's receivedRoutes Table: %v", err)
 					return
@@ -539,7 +539,7 @@ func (p *metalBondPeer) processRxUpdate(msg msgUpdate) {
 			p.log().Errorf("Could not process received route UPDATE ADD: %v", err)
 		}
 	case REMOVE:
-		err, _ = p.receivedRoutes.RemoveNextHop(msg.VNI, msg.Destination, msg.NextHop, p)
+		_, err = p.receivedRoutes.RemoveNextHop(msg.VNI, msg.Destination, msg.NextHop, p)
 		if err != nil {
 			p.log().Errorf("Could not remove received route from peer's receivedRoutes Table: %v", err)
 			return

routetable.go

@@ -102,7 +102,7 @@ func (rt *routeTable) GetNextHopsByDestination(vni VNI, dest Destination) []Next
 	return nh
 }
 
-func (rt *routeTable) RemoveNextHop(vni VNI, dest Destination, nh NextHop, receivedFrom *metalBondPeer) (error, int) {
+func (rt *routeTable) RemoveNextHop(vni VNI, dest Destination, nh NextHop, receivedFrom *metalBondPeer) (int, error) {
 	rt.rwmtx.Lock()
 	defer rt.rwmtx.Unlock()
 
@@ -112,19 +112,19 @@ func (rt *routeTable) RemoveNextHop(vni VNI, dest Destination, nh NextHop, recei
 
 	// TODO Performance: reused found map pointers
 	if _, exists := rt.routes[vni]; !exists {
-		return fmt.Errorf("VNI does not exist"), 0
+		return 0, fmt.Errorf("VNI does not exist")
 	}
 
 	if _, exists := rt.routes[vni][dest]; !exists {
-		return fmt.Errorf("Destination does not exist"), 0
+		return 0, fmt.Errorf("destination does not exist")
 	}
 
 	if _, exists := rt.routes[vni][dest][nh]; !exists {
-		return fmt.Errorf("Nexthop does not exist"), 0
+		return 0, fmt.Errorf("nexthop does not exist")
 	}
 
 	if _, exists := rt.routes[vni][dest][nh][receivedFrom]; !exists {
-		return fmt.Errorf("ReceivedFrom does not exist"), 0
+		return 0, fmt.Errorf("receivedFrom does not exist")
 	}
 
 	delete(rt.routes[vni][dest][nh], receivedFrom)
@@ -142,7 +142,7 @@ func (rt *routeTable) RemoveNextHop(vni VNI, dest Destination, nh NextHop, recei
 		delete(rt.routes, vni)
 	}
 
-	return nil, left
+	return left, nil
 }
 
 func (rt *routeTable) AddNextHop(vni VNI, dest Destination, nh NextHop, receivedFrom *metalBondPeer) error {