HA setup with pg pool in docker

Hi Team,

We are planning to build a HA setup with pgpool in docker, Could you please
let us know prerequisites for it.

1. How many servers are needed for this?, can we plan with 2 servers like
below config.
Primary instance and pgpool in two different docker containers in server
1 and standby instance in docker container server 2.

2. User requirement: any user needs password less authentication between
nodes.

3. Port or firewall rules between servers.

4. If planning to create a network bridge between all docker containers
between 2 servers will be any prerequisites for that.

Thanks in advance.

Regards,
Vasu Madhineni