Merge pull request #589 from go-redis/fix/avoid-cluster-loopback

Use node address instead of relying on loopback reported by redis

Author: vmihailenco

Diff for: cluster.go

@@ -3,6 +3,7 @@ package redis
 import (
 	"fmt"
 	"math/rand"
+	"net"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -244,16 +245,22 @@ type clusterState struct {
 	slots [][]*clusterNode
 }
 
-func newClusterState(nodes *clusterNodes, slots []ClusterSlot) (*clusterState, error) {
+func newClusterState(nodes *clusterNodes, slots []ClusterSlot, origin string) (*clusterState, error) {
 	c := clusterState{
 		nodes: nodes,
 		slots: make([][]*clusterNode, hashtag.SlotNumber),
 	}
 
+	isLoopbackOrigin := isLoopbackAddr(origin)
 	for _, slot := range slots {
 		var nodes []*clusterNode
 		for _, slotNode := range slot.Nodes {
-			node, err := c.nodes.Get(slotNode.Addr)
+			addr := slotNode.Addr
+			if !isLoopbackOrigin && isLoopbackAddr(addr) {
+				addr = origin
+			}
+
+			node, err := c.nodes.Get(addr)
 			if err != nil {
 				return nil, err
 			}
@@ -661,7 +668,7 @@ func (c *ClusterClient) reloadSlots() (*clusterState, error) {
 		return nil, err
 	}
 
-	return newClusterState(c.nodes, slots)
+	return newClusterState(c.nodes, slots, node.Client.opt.Addr)
 }
 
 // reaper closes idle connections to the cluster.
@@ -960,3 +967,17 @@ func (c *ClusterClient) txPipelineReadQueued(
 
 	return firstErr
 }
+
+func isLoopbackAddr(addr string) bool {
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		return false
+	}
+
+	ip := net.ParseIP(host)
+	if ip == nil {
+		return false
+	}
+
+	return ip.IsLoopback()
+}

Diff for: commands_test.go

@@ -2888,12 +2888,12 @@ var _ = Describe("Commands", func() {
 		It("returns map of commands", func() {
 			cmds, err := client.Command().Result()
 			Expect(err).NotTo(HaveOccurred())
-			Expect(len(cmds)).To(BeNumerically("~", 173, 5))
+			Expect(len(cmds)).To(BeNumerically("~", 180, 10))
 
 			cmd := cmds["mget"]
 			Expect(cmd.Name).To(Equal("mget"))
 			Expect(cmd.Arity).To(Equal(int8(-2)))
-			Expect(cmd.Flags).To(Equal([]string{"readonly"}))
+			Expect(cmd.Flags).To(ContainElement("readonly"))
 			Expect(cmd.FirstKeyPos).To(Equal(int8(1)))
 			Expect(cmd.LastKeyPos).To(Equal(int8(-1)))
 			Expect(cmd.StepCount).To(Equal(int8(1)))