Calculate node name by using network stack

cmd/olricd/server/memberlist.go

@@ -15,12 +15,11 @@
 package server
 
 import (
-	"fmt"
-	"net"
 	"os"
 	"time"
 
 	"github.com/buraksezer/olric/config"
+	"github.com/buraksezer/olric/internal/network"
 	m "github.com/hashicorp/memberlist"
 )
 
@@ -100,19 +99,11 @@ func newMemberlistConf(c *Config) (*m.Config, error) {
 	if c.Memberlist.AdvertiseAddr != nil {
 		mc.AdvertiseAddr = *c.Memberlist.AdvertiseAddr
 	} else {
-		if ip := net.ParseIP(mc.BindAddr); ip != nil {
-			mc.AdvertiseAddr = ip.String()
-		} else {
-			ans, err := net.LookupIP(mc.BindAddr)
-			if err != nil {
-				return nil, err
-			}
-			// Fail early.
-			if len(ans) == 0 {
-				return nil, fmt.Errorf("no IP address found for %s", mc.BindAddr)
-			}
-			mc.AdvertiseAddr = ans[0].String()
+		advertiseAddr, err := network.ParseOrLookupIP(mc.BindAddr)
+		if err != nil {
+			return nil, err
 		}
+		mc.AdvertiseAddr = advertiseAddr.String()
 	}
 	if c.Memberlist.AdvertisePort != nil {
 		mc.AdvertisePort = *c.Memberlist.AdvertisePort

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/cespare/xxhash v1.1.0
 	github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e
 	github.com/hashicorp/go-multierror v1.0.0
+	github.com/hashicorp/go-sockaddr v1.0.0
 	github.com/hashicorp/logutils v1.0.0
 	github.com/hashicorp/memberlist v0.1.5
 	github.com/pkg/errors v0.9.1

internal/discovery/discovery.go

@@ -1,4 +1,4 @@
-// Copyright 2018-2019 Burak Sezer
+// Copyright 2018-2020 Burak Sezer
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -123,16 +123,15 @@ func (d *Discovery) DecodeNodeMeta(buf []byte) (Member, error) {
 // New creates a new memberlist with a proper configuration and returns a new Discovery instance along with it.
 func New(log *flog.Logger, c *config.Config) (*Discovery, error) {
 	// Calculate host's identity. It's useful to compare hosts.
-	name := net.JoinHostPort(c.BindAddr, strconv.Itoa(c.BindPort))
 	birthdate := time.Now().UnixNano()
 
-	buf := make([]byte, 8+len(name))
+	buf := make([]byte, 8+len(c.MemberlistConfig.Name))
 	binary.BigEndian.PutUint64(buf, uint64(birthdate))
-	buf = append(buf, []byte(name)...)
+	buf = append(buf, []byte(c.MemberlistConfig.Name)...)
 
 	id := c.Hasher.Sum64(buf)
 	host := &Member{
-		Name:      name,
+		Name:      c.MemberlistConfig.Name,
 		ID:        id,
 		Birthdate: birthdate,
 	}

internal/network/ip.go

@@ -0,0 +1,78 @@
+// Copyright 2018-2020 Burak Sezer
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*Package network provides utility functions for network-related tasks*/
+package network
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/hashicorp/go-sockaddr"
+)
+
+func ParseOrLookupIP(addr string) (net.IP, error) {
+	if ip := net.ParseIP(addr); ip != nil {
+		return ip, nil
+	}
+
+	ans, err := net.LookupIP(addr)
+	if err != nil {
+		return nil, err
+	}
+	// Fail early.
+	if len(ans) == 0 {
+		return nil, fmt.Errorf("no IP address found for %s", addr)
+	}
+	return ans[0], nil
+}
+
+func AddrToIP(addr string) (net.IP, error) {
+	ip, err := ParseOrLookupIP(addr)
+	if err != nil {
+		return nil, err
+	}
+	ipStr := ip.String()
+
+	var advertiseAddr net.IP
+	if ipStr == "0.0.0.0" {
+		// Otherwise, if we're not bound to a specific IP, let's
+		// use a suitable private IP address.
+		var err error
+		ipStr, err = sockaddr.GetPrivateIP()
+		if err != nil {
+			return nil, fmt.Errorf("failed to get interface addresses: %v", err)
+		}
+		if ipStr == "" {
+			return nil, fmt.Errorf("no private IP address found, and explicit IP not provided")
+		}
+
+		advertiseAddr = net.ParseIP(ipStr)
+		if advertiseAddr == nil {
+			return nil, fmt.Errorf("failed to parse advertise address: %q", ipStr)
+		}
+	} else {
+		// If they've supplied an address, use that.
+		advertiseAddr = net.ParseIP(ipStr)
+		if advertiseAddr == nil {
+			return nil, fmt.Errorf("failed to parse advertise address %q", ipStr)
+		}
+
+		// Ensure IPv4 conversion if necessary.
+		if ip4 := advertiseAddr.To4(); ip4 != nil {
+			advertiseAddr = ip4
+		}
+	}
+	return advertiseAddr, nil
+}

olric.go

@@ -32,6 +32,7 @@ import (
 	"github.com/buraksezer/olric/internal/discovery"
 	"github.com/buraksezer/olric/internal/flog"
 	"github.com/buraksezer/olric/internal/locker"
+	"github.com/buraksezer/olric/internal/network"
 	"github.com/buraksezer/olric/internal/protocol"
 	"github.com/buraksezer/olric/internal/storage"
 	"github.com/buraksezer/olric/internal/transport"
@@ -234,9 +235,12 @@ func New(c *config.Config) (*Olric, error) {
 		return nil, err
 	}
 
+	bindAddr, err := network.AddrToIP(c.BindAddr)
+	if err != nil {
+		return nil, err
+	}
 	// Set the name of this node in the cluster
-	name := net.JoinHostPort(c.BindAddr, strconv.Itoa(c.BindPort))
-	c.MemberlistConfig.Name = name
+	c.MemberlistConfig.Name = net.JoinHostPort(bindAddr.String(), strconv.Itoa(c.BindPort))
 
 	cfg := consistent.Config{
 		Hasher:            c.Hasher,
@@ -266,7 +270,7 @@ func New(c *config.Config) (*Olric, error) {
 	}
 
 	db := &Olric{
-		name:       name,
+		name:       c.MemberlistConfig.Name,
 		ctx:        ctx,
 		cancel:     cancel,
 		log:        flogger,
@@ -485,6 +489,8 @@ func (db *Olric) Start() error {
 				db.config.WriteQuorum)
 	}
 
+	db.log.V(2).Printf("[INFO] Node name in the cluster: %s", db.name)
+
 	// Start periodic tasks.
 	db.wg.Add(2)
 	go db.updateRoutingPeriodically()