consumer: fix panic in nextLookupdEndpoint

consumer.go

@@ -340,20 +340,21 @@ func (r *Consumer) ConnectToNSQLookupd(addr string) error {
 		return errors.New("no handlers")
 	}
 
-	if err := validatedLookupAddr(addr); err != nil {
+	parsedAddr, err := buildLookupAddr(addr, r.topic)
+	if err != nil {
 		return err
 	}
 
 	atomic.StoreInt32(&r.connectedFlag, 1)
 
 	r.mtx.Lock()
 	for _, x := range r.lookupdHTTPAddrs {
-		if x == addr {
+		if x == parsedAddr {
 			r.mtx.Unlock()
 			return nil
 		}
 	}
-	r.lookupdHTTPAddrs = append(r.lookupdHTTPAddrs, addr)
+	r.lookupdHTTPAddrs = append(r.lookupdHTTPAddrs, parsedAddr)
 	numLookupd := len(r.lookupdHTTPAddrs)
 	r.mtx.Unlock()
 
@@ -383,20 +384,6 @@ func (r *Consumer) ConnectToNSQLookupds(addresses []string) error {
 	return nil
 }
 
-func validatedLookupAddr(addr string) error {
-	if strings.Contains(addr, "/") {
-		_, err := url.Parse(addr)
-		if err != nil {
-			return err
-		}
-		return nil
-	}
-	if !strings.Contains(addr, ":") {
-		return errors.New("missing port")
-	}
-	return nil
-}
-
 // poll all known lookup servers every LookupdPollInterval
 func (r *Consumer) lookupdLoop() {
 	// add some jitter so that multiple consumers discovering the same topic,
@@ -446,23 +433,7 @@ func (r *Consumer) nextLookupdEndpoint() string {
 	r.mtx.RUnlock()
 	r.lookupdQueryIndex = (r.lookupdQueryIndex + 1) % num
 
-	urlString := addr
-	if !strings.Contains(urlString, "://") {
-		urlString = "http://" + addr
-	}
-
-	u, err := url.Parse(urlString)
-	if err != nil {
-		panic(err)
-	}
-	if u.Path == "/" || u.Path == "" {
-		u.Path = "/lookup"
-	}
-
-	v, err := url.ParseQuery(u.RawQuery)
-	v.Add("topic", r.topic)
-	u.RawQuery = v.Encode()
-	return u.String()
+	return addr
 }
 
 type lookupResp struct {
@@ -659,10 +630,15 @@ func (r *Consumer) DisconnectFromNSQD(addr string) error {
 // DisconnectFromNSQLookupd removes the specified `nsqlookupd` address
 // from the list used for periodic discovery.
 func (r *Consumer) DisconnectFromNSQLookupd(addr string) error {
+	parsedAddr, err := buildLookupAddr(addr, r.topic)
+	if err != nil {
+		return err
+	}
+
 	r.mtx.Lock()
 	defer r.mtx.Unlock()
 
-	idx := indexOf(addr, r.lookupdHTTPAddrs)
+	idx := indexOf(parsedAddr, r.lookupdHTTPAddrs)
 	if idx == -1 {
 		return ErrNotConnected
 	}
@@ -1204,3 +1180,28 @@ func (r *Consumer) log(lvl LogLevel, line string, args ...interface{}) {
 		lvl, r.id, r.topic, r.channel,
 		fmt.Sprintf(line, args...)))
 }
+
+func buildLookupAddr(addr, topic string) (string, error) {
+	urlString := addr
+	if !strings.Contains(urlString, "://") {
+		urlString = "http://" + addr
+	}
+
+	u, err := url.Parse(urlString)
+	if err != nil {
+		return "", err
+	}
+
+	if u.Port() == "" {
+		return "", errors.New("missing port")
+	}
+
+	if u.Path == "/" || u.Path == "" {
+		u.Path = "/lookup"
+	}
+
+	v, err := url.ParseQuery(u.RawQuery)
+	v.Add("topic", topic)
+	u.RawQuery = v.Encode()
+	return u.String(), nil
+}