I'm looking for the best way to get access to a service running in container in ECS cluster "A" from another container running in ECS cluster "B".
I don't want to make any ports public.

Currently I found a way to have it working in the same VPC - by adding security group of instance of cluster "B" to inbound rule of security group of cluster "A", after that services from cluster "A" are available in containers running in "B" by 'private ip address'.

But that requires this security rule to be added (which is not convenient) and won't work for different regions. Maybe there's better solution which covers both cases - same VPC and region and different VPCs and regions?