Hello, I'm trying to setup a k3s cluster with 3 masters and 3 workers node, following the HA architecture detailed here. I have created the 3 masters (registered master2 and master3 using the IP address of master1) but I'm now wondering if it works the same for the agents/workers? Or do I need to do something like:

curl -sfL <https://get.k3s.io> | K3S_TOKEN=<K3S_TOKEN> sh -s - agent \
  --server <https://10.56.0.1:6443> \         # Master 1
  --server <https://10.56.0.2:6443> \         # Master 2
  --server <https://10.56.0.3:6443>           # Master 3

https://docs.k3s.io/datastore/ha-embedded

• Optional: A fixed registration address for agent nodes to register with the cluster

You can only point agents at a single address. This is why we recommend use of a fixed registration address - whether thats an external LB in front of the servers, or a DNS alias, or something else that you come up with.

whether thats an external LB in front of the servers

For example, by using kube-vip: https://kube-vip.io/docs/usage/k3s/ (Other load balancers are available)

Thanks for the responses @creamy-pencil-82913 amd @sticky-summer-13450 I have one more additional question, looks like my metrics server try to fetch the metrics from the agent using their public IPs but the firewall is closed. Is there any settings to configure that all inter nodes traffic must use the private network?