add readOnly on failover opts

universal.go

@@ -163,6 +163,8 @@ func (o *UniversalOptions) Failover() *FailoverOptions {
 
 		TLSConfig: o.TLSConfig,
 
+		ReplicaOnly:     o.ReadOnly,
+
 		DisableIndentity: o.DisableIndentity,
 		IdentitySuffix:   o.IdentitySuffix,
 		UnstableResp3:    o.UnstableResp3,

universal_test.go

@@ -60,6 +60,29 @@ var _ = Describe("UniversalClient", func() {
 		Expect(a).ToNot(Panic())
 	})
 
+	It("should connect to failover servers on slaves when readonly Options is ok", Label("NonRedisEnterprise"), func() {
+		client = redis.NewUniversalClient(&redis.UniversalOptions{
+			MasterName: sentinelName,
+			Addrs:      sentinelAddrs,
+			ReadOnly: true,
+		})
+		Expect(client.Ping(ctx).Err()).NotTo(HaveOccurred())
+
+
+		roleCmd := client.Do(ctx, "ROLE")
+        role, err := roleCmd.Result()
+        Expect(err).NotTo(HaveOccurred())
+
+        roleSlice, ok := role.([]interface{})
+        Expect(ok).To(BeTrue())
+        Expect(roleSlice[0]).To(Equal("slave"))
+
+
+		err = client.Set(ctx, "somekey", "somevalue", 0).Err()
+        Expect(err).To(HaveOccurred())
+
+	})
+
 	It("should connect to clusters if IsClusterMode is set even if only a single address is provided", Label("NonRedisEnterprise"), func() {
 		client = redis.NewUniversalClient(&redis.UniversalOptions{
 			Addrs:         []string{cluster.addrs()[0]},
@@ -77,3 +100,4 @@ var _ = Describe("UniversalClient", func() {
 		Expect(client.ClusterSlots(ctx).Val()).To(HaveLen(3))
 	})
 })
+