Playbook will also install software-properties-common. Removed hardcoded host name.

lxc_setup_ubuntu.yml

@@ -1,6 +1,6 @@
 ---
 - name: Secure and Configure a New LXC Container
-  hosts: ansible # Hosts or group defined in your inventory
+  hosts: '{{ hosts_to_work_on }}' # Hosts or group defined in your inventory
   become: yes # Run all tasks as root (sudo)
   tasks:
     - name: 1. Create user '{{ target_user }}'
@@ -31,6 +31,12 @@
         name: '{{ target_user }}'
         password_lock: yes
 
+    - name: 4.0. Install software-properties-common
+      ansible.builtin.apt:
+        name: software-properties-common
+        state: present
+        update_cache: yes
+
     - name: 4.1. Disallow root login over SSH
       ansible.builtin.lineinfile:
         path: /etc/ssh/sshd_config
@@ -54,4 +60,4 @@
       listen: "restart sshd"
       ansible.builtin.service:
         name: sshd
-        state: restarted
+        state: restarted

vars.yml

@@ -3,4 +3,6 @@ target_user: 'mbuz'
 my_public_keys:
   - "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAINSGj0dxaA38QSBVY3DZiPb+qmIuTFxGo0mt4sbmYDa3 mbuz@macbook-pro"
   - "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOpvRkew+XpOAt7I/mizQbE/OJP1SO6NVl2/A1ZGzdU3 mbuz@windows-desktop"
-  - "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIGWMJbHDCB8XCxPGth1229A3W/sPpvJHO9xBvegv4Sx mbuz@macbook-air"
+  - "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIGWMJbHDCB8XCxPGth1229A3W/sPpvJHO9xBvegv4Sx mbuz@macbook-air"
+
+hosts_to_work_on: ansible