Add support for embedded DB HA mode

[kopwei]

Since v1.19.5, K3s added support for HA mode with embedded ETCD and I hope this could be supported in Ansible scripts.

The document is described at K3s HA Embedded mode

Generally. First we shall define "K3S_TOKEN" as an input value, the value should be a string without special chars. e.g. "mySecret123",

• On first master node, k3s should start via command "K3S_TOKEN='mySeceret123' k3s server --cluster-init [--extra server config]"
• On other master, k3s should start via command "K3S_TOKEN='mySecret123' k3s server --server=https://<IP_OF_1st_MASTER>:6443 [--extra server config]"
• For the rest worker nodes, k3s shall start as k3s-agent as before

[212850a]

It's already implemented in this repo - https://github.com/k3s-io/k3s-ansible/tree/k3s-ha ;)

[2fst4u]

It's also in this issue #32

[TwoTwenty]

will these changes be merged into master?

[dtaivpp]

will these changes be merged into master?

Curious about this as well. Seems to automatically detect if there are multiple masters so I don't see why it couldn't be added back in.