feat: support Elasticache cluster mode by introducing IsClusterMode config param

Author: joshirushikesh

universal.go

@@ -69,6 +69,10 @@ type UniversalOptions struct {
 	DisableIndentity bool
 	IdentitySuffix   string
 	UnstableResp3    bool
+
+	// This is required because Elasticache supports setting up cluster mode with configuration endpoint. So the check len(Addrs) > 1 is not enough for determining cluster mode.
+	// If IsClusterMode is true, the client will be created as a cluster client.
+	IsClusterMode bool
 }
 
 // Cluster returns cluster options created from the universal options.
@@ -243,7 +247,7 @@ var (
 func NewUniversalClient(opts *UniversalOptions) UniversalClient {
 	if opts.MasterName != "" {
 		return NewFailoverClient(opts.Failover())
-	} else if len(opts.Addrs) > 1 {
+	} else if len(opts.Addrs) > 1 || opts.IsClusterMode {
 		return NewClusterClient(opts.Cluster())
 	}
 	return NewClient(opts.Simple())

universal_test.go

@@ -38,4 +38,13 @@ var _ = Describe("UniversalClient", func() {
 		})
 		Expect(client.Ping(ctx).Err()).NotTo(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]},
+			IsClusterMode: true,
+		})
+		_, ok := client.(*redis.ClusterClient)
+		Expect(ok).To(BeTrue(), "expected a ClusterClient")
+	})
 })