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/master/defaults/main.yml

@@ -1,5 +1,4 @@
 ---
-ansible_user: root
 server_init_args: >-
   {% if groups['master'] | length > 1 %}
     {% if ansible_hostname == hostvars[groups['master'][0]]['ansible_hostname'] %}

roles/k3s/master/tasks/main.yml

@@ -97,24 +97,24 @@
 
 - name: Create directory .kube
   file:
-    path: ~{{ ansible_user }}/.kube
+    path: "{{ ansible_user_dir }}/.kube"
     state: directory
-    owner: "{{ ansible_user }}"
+    owner: "{{ ansible_user_id }}"
     mode: "u=rwx,g=rx,o="
 
 - name: Copy config file to user home directory
   copy:
     src: /etc/rancher/k3s/k3s.yaml
-    dest: ~{{ ansible_user }}/.kube/config
+    dest: "{{ ansible_user_dir }}/.kube/config"
     remote_src: yes
-    owner: "{{ ansible_user }}"
+    owner: "{{ ansible_user_id }}"
     mode: "u=rw,g=,o="
 
 - name: Configure kubectl cluster to {{ endpoint_url }}
   command: >-
     k3s kubectl config set-cluster default
       --server={{ endpoint_url }}
-      --kubeconfig ~{{ ansible_user }}/.kube/config
+      --kubeconfig {{ ansible_user_dir }}/.kube/config
   changed_when: true
   vars:
     endpoint_url: >-