refactor: yml -> yaml

Signed-off-by: Tuan-Dat Tran <tuan-dat.tran@tudattr.dev>

roles/k3s_server/tasks/secondary_installation.yaml

@@ -0,0 +1,21 @@
+---
+- name: Add token vault
+  ansible.builtin.include_vars:
+    file: "{{ playbook_dir }}/{{ k3s_server_token_vault_file }}"
+    name: k3s_token_vault
+
+- name: Download K3s install script to /tmp/
+  ansible.builtin.get_url:
+    url: https://get.k3s.io
+    dest: /tmp/k3s_install.sh
+    mode: "0755"
+
+- name: Install K3s on the secondary servers
+  ansible.builtin.command: |
+    /tmp/k3s_install.sh \
+    --server "https://{{ hostvars['k3s-loadbalancer'].ansible_default_ipv4.address }}:{{ k3s.loadbalancer.default_port }}" \
+    --tls-san {{ hostvars['k3s-loadbalancer'].ansible_default_ipv4.address }} \
+    --tls-san {{ k3s_server_name }}
+  environment:
+    K3S_TOKEN: "{{ k3s_token_vault.k3s_token }}"
+  become: true