Connecting to AWS ElastiCache Redis in cluster mode behind NAT

### Expected behavior I want to be able to use Redisson when Redis Cluster is behind NAT. I can think of following solutions:

1. Disable auto discovery and use ElastiCache Management Nodes for all request (prefered approach recommendation in aws doc).
2. Disabling auto discovery by manually registering all nodes in Redisson.
3. Provide customer provide DNS mapping

I am using AWS ElastiCache Redis in cluster mode where AWS creates a management endpoint for whole cluster and separate endpoint for each master node. My whole cluster is behind NAT, so when Redisson tries to discover all the nodes in the cluster it find their local IP not the NAT IP, as a result it fails to connect to clustered nodes.

Actual behavior

Redisson discovers all the nodes in the clusters and tries to connect to them. However it fails because those IP/endpoints are behind NAT.

Steps to reproduce or test case

Create an AWS ElastiCache Redis stack in cluster mode. Create a NAT on top of it and try to connect to the NATed cluster.

Redis version

3.2.10

Redisson version

3.6.5

Redisson configuration

        config.useReplicatedServers().addNodeAddress("Cluster Management Endpoint)
            .setConnectTimeout(500)
            .setMasterConnectionPoolSize(20)
            .setReadMode(ReadMode.MASTER);

[jackygurui]

Based on the redis document, NAT is currently not supported in cluster mode.

https://redis.io/topics/cluster-tutorial#redis-cluster-and-docker

[sailsgo]

@soheil-jazayeri I also encountered the same problem,How do you solve this issue? thanks