Do not rely on ansible_user (#214)

* Apply "become" on roles instead of plays

This leads to facts being gathered for the "regular" login user, instead
of root.

* Do not rely on ansible_user

Instead of reading ansible_user (which may or may not be defined), this
patch lets the roles rely on Ansible facts [1].

[1]: https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_vars_facts.html

roles/k3s/post/tasks/metallb.yml

@@ -3,7 +3,7 @@
   file:
     path: /tmp/k3s
     state: directory
-    owner: "{{ ansible_user }}"
+    owner: "{{ ansible_user_id }}"
     mode: 0755
   with_items: "{{ groups['master'] }}"
   run_once: true
@@ -12,7 +12,7 @@
   template:
     src: "metallb.crs.j2"
     dest: "/tmp/k3s/metallb-crs.yaml"
-    owner: "{{ ansible_user }}"
+    owner: "{{ ansible_user_id }}"
     mode: 0755
   with_items: "{{ groups['master'] }}"
   run_once: true