Question: Multiple pg clusters on one server can be reached with the standard port.

Hello all,

I am currently looking for a solution similar to Oracle Listener.

Current situation:
I have a system with multiple PostgreSQL clusters for different databases.
Each cluster is running on the same physical machine and is accessed through its own DNS alias and corresponding port.
I only have one single IP address available, and there is no possibility of obtaining additional addresses.

Here's an example:

DNS ALIAS Host
─> pgs1.server.net:5432 ─> PG_Cluster1(at)192(dot)168(dot)0(dot)1:5432
─> pgs2.server.net:5433 ─> PG_Cluster2(at)192(dot)168(dot)0(dot)1:5433
─> pgs3.server.net:5434 ─> PG_Cluster3(at)192(dot)168(dot)0(dot)1:5434
─> pgs4.server.net:5435 ─> PG_Cluster4(at)192(dot)168(dot)0(dot)1:5435
─> pgs5.server.net:5436 ─> PG_Cluster5(at)192(dot)168(dot)0(dot)1:5436

Desired solution:
I still want to use the same system with different PostgreSQL clusters for the various databases.
These clusters are internally accessible through different ports.
However, I would like a service on the server to receive all external requests on port 5432 and forward them to the corresponding internal cluster based on the DNS alias.
It would also be desirable if this service could provide additional features like connection pooling or other functionalities.
Similar to a reverse proxy.

Here's an example:

DNS ALIAS HOST
─> pgs1.server.net:5432 ─┐ ┌──────────────────┬──> PG_Cluster1(at)localhost:5433
─> pgs2.server.net:5432 ─┤ │ ├──> PG_Cluster2(at)localhost:5434
─> pgs3.server.net:5432 ─┼─>─┤ 192.168.0.1:5432 ├──> PG_Cluster3(at)localhost:5435
─> pgs4.server.net:5432 ─┤ │ ├──> PG_Cluster4(at)localhost:5436
─> pgs5.server.net:5432 ─┘ └──────────────────┴──> PG_Cluster5(at)localhost:5437

Is there a solution for this, and what are the advantages or limitations that arise from it?

Thank you in advance for your suggestions and help.

Regards,
Michael