fixed some linting errors

found them using

```
gometalinter --skip=vendor --disable-all --enable=megacheck --enable=deadcode --enable=ineffassign --enable=interfacer --enable=errcheck ./...
```

cmd/dht.go

@@ -62,7 +62,11 @@ func dhtCmd(cmd *cobra.Command, args []string) {
 		}
 
 		d := dht.New(dhtConf)
-		d.Start()
+		err := d.Start()
+		if err != nil {
+			log.Println("error starting dht: " + err.Error())
+			return
+		}
 
 		interruptChan := make(chan os.Signal, 1)
 		signal.Notify(interruptChan, os.Interrupt, syscall.SIGTERM, syscall.SIGINT)

cmd/root.go

@@ -116,9 +116,5 @@ func loadConfig(path string) (Config, error) {
 	}
 
 	err = json.Unmarshal(raw, &c)
-	if err != nil {
 	return c, err
 }
-
-	return c, nil
-}

db/db.go

@@ -296,6 +296,7 @@ func (s *SQL) GetStoredHashesInRange(ctx context.Context, start, end bits.Bitmap
 		}
 
 		var hash string
+	ScanLoop:
 		for rows.Next() {
 			err := rows.Scan(&hash)
 			if err != nil {
@@ -304,7 +305,7 @@ func (s *SQL) GetStoredHashesInRange(ctx context.Context, start, end bits.Bitmap
 			}
 			select {
 			case <-ctx.Done():
-				break
+				break ScanLoop
 			case ch <- bits.FromHexP(hash):
 			}
 		}

dht/contact.go

@@ -108,12 +108,7 @@ func (c *Contact) UnmarshalBencode(b []byte) error {
 		return errors.Err("invalid IP")
 	}
 
-	err = bencode.DecodeBytes(raw[2], &c.Port)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return bencode.DecodeBytes(raw[2], &c.Port)
 }
 
 func sortByDistance(contacts []Contact, target bits.Bitmap) {

dht/dht.go

@@ -70,11 +70,7 @@ func (dht *DHT) connect(conn UDPConn) error {
 	dht.node = NewNode(contact.ID)
 	dht.tokenCache = newTokenCache(dht.node, tokenSecretRotationInterval)
 
-	err = dht.node.Connect(conn)
-	if err != nil {
-		return err
-	}
-	return nil
+	return dht.node.Connect(conn)
 }
 
 // Start starts the dht

dht/dht_announce.go

@@ -57,7 +57,11 @@ func (dht *DHT) runAnnouncer() {
 		defer dht.grp.Done()
 		limiter := rate.NewLimiter(rate.Limit(dht.conf.AnnounceRate), dht.conf.AnnounceRate)
 		for {
-			limiter.Wait(context.Background()) // TODO: should use grp.ctx somehow? so when grp is closed, wait returns
+			err := limiter.Wait(context.Background()) // TODO: should use grp.ctx somehow? so when grp is closed, wait returns
+			if err != nil {
+				log.Error(errors.Prefix("rate limiter", err))
+				continue
+			}
 			select {
 			case limitCh <- time.Now():
 			case <-dht.grp.Ch():

dht/node_finder.go

@@ -250,10 +250,6 @@ func (cf *contactFinder) probe(cycleID string) *Contact {
 	return cf.closest(res.Contacts...)
 }
 
-func (cf *contactFinder) probeClosestOutstanding() {
-
-}
-
 // appendNewToShortlist appends any new contacts to the shortlist and sorts it by distance
 // contacts that have already been added to the shortlist in the past are ignored
 func (cf *contactFinder) appendNewToShortlist(contacts []Contact) {
@@ -320,11 +316,7 @@ func (cf *contactFinder) isSearchFinished() bool {
 
 	cf.activeContactsMutex.Lock()
 	defer cf.activeContactsMutex.Unlock()
-	if len(cf.activeContacts) >= bucketSize {
-		return true
-	}
-
-	return false
+	return len(cf.activeContacts) >= bucketSize
 }
 
 func (cf *contactFinder) debug(format string, args ...interface{}) {

dht/routing_table.go

@@ -263,14 +263,20 @@ func (rt *routingTable) Update(c Contact) {
 		}
 	}
 
-	b.UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, true)
+	err := b.UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, true)
+	if err != nil {
+		log.Error(err)
+	}
 }
 
 // Fresh refreshes a contact if its already in the routing table
 func (rt *routingTable) Fresh(c Contact) {
 	rt.mu.RLock()
 	defer rt.mu.RUnlock()
-	rt.bucketFor(c.ID).UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, false)
+	err := rt.bucketFor(c.ID).UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, false)
+	if err != nil {
+		log.Error(err)
+	}
 }
 
 // FailContact marks a contact as having failed, and removes it if it failed too many times

dht/rpc.go

@@ -110,6 +110,9 @@ func (rpc *rpcReceiver) IterativeFindValue(r *http.Request, args *RpcIterativeFi
 		return err
 	}
 	foundContacts, found, err := FindContacts(rpc.dht.node, key, false, nil)
+	if err != nil {
+		return err
+	}
 	result.Contacts = foundContacts
 	result.FoundValue = found
 	return nil
@@ -153,7 +156,11 @@ func (dht *DHT) runRPCServer(port int) {
 	s := rpc2.NewServer()
 	s.RegisterCodec(json.NewCodec(), "application/json")
 	s.RegisterCodec(json.NewCodec(), "application/json;charset=UTF-8")
-	s.RegisterService(&rpcReceiver{dht: dht}, "rpc")
+	err := s.RegisterService(&rpcReceiver{dht: dht}, "rpc")
+	if err != nil {
+		log.Error(errors.Prefix("registering rpc service", err))
+		return
+	}
 
 	handler := mux.NewRouter()
 	handler.Handle("/", s)
@@ -171,6 +178,10 @@ func (dht *DHT) runRPCServer(port int) {
 	}()
 
 	<-dht.grp.Ch()
-	server.Shutdown(context.Background())
+	err = server.Shutdown(context.Background())
+	if err != nil {
+		log.Error(errors.Prefix("shutting down rpc service", err))
+		return
+	}
 	wg.Wait()
 }

peer/server.go

@@ -105,9 +105,8 @@ func (s *Server) handleConnection(conn net.Conn) {
 	for {
 		var request []byte
 		var response []byte
-		var err error
 
-		err = conn.SetReadDeadline(time.Now().Add(timeoutDuration))
+		err := conn.SetReadDeadline(time.Now().Add(timeoutDuration))
 		if err != nil {
 			log.Error(errors.FullTrace(err))
 		}

prism/prism.go

@@ -122,12 +122,7 @@ func (p *Prism) Start() error {
 		return err
 	}
 
-	err = p.cluster.Connect()
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return p.cluster.Connect()
 }
 
 // Shutdown gracefully shuts down the different prism components before exiting.

reflector/server.go

@@ -206,13 +206,9 @@ func (s *Server) doHandshake(conn net.Conn) error {
 	}
 
 	_, err = conn.Write(resp)
-	if err != nil {
 	return err
 }
 
-	return nil
-}
-
 func (s *Server) readBlobRequest(conn net.Conn) (int, string, bool, error) {
 	var sendRequest sendBlobRequest
 	err := json.NewDecoder(conn).Decode(&sendRequest)
@@ -257,11 +253,8 @@ func (s *Server) sendBlobResponse(conn net.Conn, blobExists, isSdBlob bool) erro
 	}
 
 	_, err = conn.Write(response)
-	if err != nil {
 	return err
 }
-	return nil
-}
 
 func (s *Server) sendTransferResponse(conn net.Conn, receivedBlob, isSdBlob bool) error {
 	var response []byte
@@ -278,8 +271,5 @@ func (s *Server) sendTransferResponse(conn net.Conn, receivedBlob, isSdBlob bool
 	}
 
 	_, err = conn.Write(response)
-	if err != nil {
 	return err
 }
-	return nil
-}