FEATURE: adds a hostname validation for lxc deployment playbook

playbooks/deploy_and_set_up_lxc_on_proxmox.yaml

@@ -12,7 +12,7 @@
 
   vars_prompt:
     - name: lxc_hostname
-      prompt: "Hostname for the container"
+      prompt: "Hostname for the container (may only contain letters (a-z, A-Z), numbers (0-9), and hyphens)"
       private: false
 
     - name: lxc_root_password
@@ -25,6 +25,14 @@
       prompt: "IP address for the container (in x.x.x.x/x formant)"
       private: false
 
+  pre_tasks:
+    - name: Validate hostname
+      ansible.builtin.fail:
+        msg: |
+          Invalid hostname: "{{ lxc_hostname }}"
+          Hostname may only contain letters (a-z, A-Z), numbers (0-9), and hyphens (-).
+      when: not lxc_hostname is regex('^[a-zA-Z0-9-]+$')
+      run_once: true
 
   roles:
     - ../roles/deploy_lxc_on_proxmox