Ignore zero addresses in CLUSTER SLOTS response

rediscluster/redisclusterutil/cluster.go

@@ -75,9 +75,16 @@ func ParseSlotsInfo(res interface{}) ([]SlotsRange, error) {
 				return errf("address format mismatch: res[%d][%d] = %+v",
 					i, j, rawrange[j])
 			}
-			host, ok := rawaddr[0].([]byte)
-			port, ok2 := rawaddr[1].(int64)
-			if !ok || !ok2 || port <= 0 || port+10000 > 65535 {
+			host, hasHost := rawaddr[0].([]byte)
+			port, hasPort := rawaddr[1].(int64)
+			if !hasHost && hasPort && port == 0 {
+				// fallback to skip zero address
+				arr, isArray := rawaddr[0].([]interface{})
+				if isArray && len(arr) == 0 {
+					continue
+				}
+			}
+			if !hasHost || !hasPort || port <= 0 || port+10000 > 65535 {
 				return errf("address format mismatch: res[%d][%d] = %+v",
 					i, j, rawaddr)
 			}

rediscluster/redisclusterutil/cluster_test.go

@@ -0,0 +1,182 @@
+package redisclusterutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseSlotsInfo(t *testing.T) {
+	clusterSlotsResponse := []interface{}{
+		[]interface{}{
+			int64(0),
+			int64(5460),
+			[]interface{}{
+				[]byte("127.0.0.1"),
+				int64(30001),
+				[]byte("09dbe9720cda62f7865eabc5fd8857c5d2678366"),
+				[]interface{}{
+					"hostname",
+					"host-1.redis.example.com",
+				},
+			},
+			[]interface{}{
+				[]byte("127.0.0.1"),
+				int64(30004),
+				[]byte("821d8ca00d7ccf931ed3ffc7e3db0599d2271abf"),
+				[]interface{}{
+					"hostname",
+					"host-2.redis.example.com",
+				},
+			},
+		},
+		[]interface{}{
+			int64(5461),
+			int64(10922),
+			[]interface{}{
+				[]byte("127.0.0.1"),
+				int64(30002),
+				[]byte("c9d93d9f2c0c524ff34cc11838c2003d8c29e013"),
+				[]interface{}{
+					"hostname",
+					"host-3.redis.example.com",
+				},
+			},
+			[]interface{}{
+				[]byte("127.0.0.1"),
+				int64(30005),
+				[]byte("faadb3eb99009de4ab72ad6b6ed87634c7ee410f"),
+				[]interface{}{
+					"hostname",
+					"host-4.redis.example.com",
+				},
+			},
+		},
+		[]interface{}{
+			int64(10923),
+			int64(16383),
+			[]interface{}{
+				[]byte("192.168.11.131"),
+				int64(30003),
+				[]byte("044ec91f325b7595e76dbcb18cc688b6a5b434a1"),
+				[]interface{}{
+					"hostname",
+					"host-5.redis.example.com",
+				},
+			},
+			[]interface{}{
+				[]byte("127.0.0.1"),
+				int64(30006),
+				[]byte("58e6e48d41228013e5d9c1c37c5060693925e97e"),
+				[]interface{}{
+					"hostname",
+					"host-6.redis.example.com",
+				},
+			},
+		},
+	}
+
+	expectedSlots := []SlotsRange{
+		{
+			From: 0,
+			To:   5460,
+			Addrs: []string{
+				"127.0.0.1:30001",
+				"127.0.0.1:30004",
+			},
+		},
+		{
+			From: 5461,
+			To:   10922,
+			Addrs: []string{
+				"127.0.0.1:30002",
+				"127.0.0.1:30005",
+			},
+		},
+		{
+			From: 10923,
+			To:   16383,
+			Addrs: []string{
+				"192.168.11.131:30003",
+				"127.0.0.1:30006",
+			},
+		},
+	}
+
+	slots, err := ParseSlotsInfo(clusterSlotsResponse)
+	require.NoError(t, err)
+
+	assert.Equal(t, expectedSlots, slots)
+}
+
+func TestParseSlotsInfo_EmptyAddress(t *testing.T) {
+	clusterSlotsResponse := []interface{}{
+		[]interface{}{
+			int64(0),
+			int64(5460),
+			[]interface{}{
+				[]byte("127.0.0.1"),
+				int64(30001),
+				[]byte("09dbe9720cda62f7865eabc5fd8857c5d2678366"),
+				[]interface{}{
+					"hostname",
+					"host-1.redis.example.com",
+				},
+			},
+			[]interface{}{
+				[]interface{}{},
+				int64(0),
+				[]byte("821d8ca00d7ccf931ed3ffc7e3db0599d2271abf"),
+				[]interface{}{
+					"hostname",
+					"host-2.redis.example.com",
+				},
+			},
+		},
+		[]interface{}{
+			int64(5461),
+			int64(10922),
+			[]interface{}{
+				[]interface{}{},
+				int64(0),
+				[]byte("c9d93d9f2c0c524ff34cc11838c2003d8c29e013"),
+				[]interface{}{
+					"hostname",
+					"host-3.redis.example.com",
+				},
+			},
+			[]interface{}{
+				[]byte("127.0.0.1"),
+				int64(30005),
+				[]byte("faadb3eb99009de4ab72ad6b6ed87634c7ee410f"),
+				[]interface{}{
+					"hostname",
+					"host-4.redis.example.com",
+				},
+			},
+		},
+	}
+
+	expectedSlots := []SlotsRange{
+		{
+			From: 0,
+			To:   5460,
+			Addrs: []string{
+				"127.0.0.1:30001",
+			},
+		},
+		{
+			From: 5461,
+			To:   10922,
+			Addrs: []string{
+				"127.0.0.1:30005",
+			},
+		},
+	}
+
+	slots, err := ParseSlotsInfo(clusterSlotsResponse)
+	require.NoError(t, err)
+
+	assert.Equal(t, expectedSlots, slots)
+}