Docs: Feedback for Start a Local Cluster in Docker

[iodog]

Hi, I have some feedback about this page
I changed the instructions so that I don't have to enter the IP of the host (which ca change), so I added to the creation of the container:
--add-host host.docker.internal:host-gateway
-e HZ_NETWORK_PUBLICADDRESS=host.docker.internal:5701
Then, following the guide I'm getting a problem where the members cannot find each other, with each member blacklisting the others for some reason.
I know it is caused by some rule in UFW (firewall, just enabled, with no additional rules) because when I disable it everything works, but that is not a good solution.
Do you have any idea how to configure UFW so that it works with the firewall enabled and preferably locally (not opening ports to external access).
Thanks.

[atilsensalduz]

The problem was UFW blocking local Docker traffic when members advertised host.docker.internal.

Fixed it by allowing traffic from the Docker network subnet to the cluster ports:

sudo ufw allow from <docker-subnet> to any port 5701 proto tcp
sudo ufw allow from <docker-subnet> to any port 5702 proto tcp

Replace with the subnet shown by:

docker network inspect hazelcast-network

Now the cluster members discover each other successfully with UFW enabled.