Add HA option, change to yaml inventory, cleanup

- HA option for multiple server nodes using embedded etcd
- Switch to yaml inventory file for easier editing and combining vars
- Update to full ansible module names
- Change master/node names to server/agent
- Cleanup small linting errors
- Add reboot playbook which staggers reboot to keep HA cluster up
- Move playbooks to playbook directory

Signed-off-by: Derek Nola <derek.nola@suse.com>

roles/k3s/agent/templates/k3s.service.j2

@@ -0,0 +1,24 @@
+[Unit]
+Description=Lightweight Kubernetes
+Documentation=https://k3s.io
+After=network-online.target
+
+[Service]
+Type=notify
+ExecStartPre=-/sbin/modprobe br_netfilter
+ExecStartPre=-/sbin/modprobe overlay
+ExecStart=/usr/local/bin/k3s agent --server https://{{ api_endpoint }}:{{ api_port }} --token {{ hostvars[groups['server'][0]]['token'] }} {{ extra_agent_args | default("") }}
+KillMode=process
+Delegate=yes
+# Having non-zero Limit*s causes performance problems due to accounting overhead
+# in the kernel. We recommend using cgroups to do container-local accounting.
+LimitNOFILE=1048576
+LimitNPROC=infinity
+LimitCORE=infinity
+TasksMax=infinity
+TimeoutStartSec=0
+Restart=always
+RestartSec=5s
+
+[Install]
+WantedBy=multi-user.target