playbooks: auto-update terraform template name after deploy

Add a third play to build-and-deploy-template.yml that updates
terraform/variables.tf with the new template name after deploying
to Proxmox. Only updates if the template name has changed.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

playbooks/build-and-deploy-template.yml

@@ -99,3 +99,48 @@
     - name: Display success message
       ansible.builtin.debug:
         msg: "Template VM {{ template_vmid }} created successfully on {{ storage }}"
+
+- name: Update Terraform template name
+  hosts: localhost
+  gather_facts: false
+
+  vars:
+    terraform_dir: "{{ playbook_dir }}/../terraform"
+
+  tasks:
+    - name: Get image filename from earlier play
+      ansible.builtin.set_fact:
+        image_filename: "{{ hostvars['localhost']['image_filename'] }}"
+
+    - name: Extract template name from image filename
+      ansible.builtin.set_fact:
+        new_template_name: "{{ image_filename | regex_replace('\\.vma\\.zst$', '') | regex_replace('^vzdump-qemu-', '') }}"
+
+    - name: Read current Terraform variables file
+      ansible.builtin.slurp:
+        src: "{{ terraform_dir }}/variables.tf"
+      register: variables_tf_content
+
+    - name: Extract current template name from variables.tf
+      ansible.builtin.set_fact:
+        current_template_name: "{{ (variables_tf_content.content | b64decode) | regex_search('variable \"default_template_name\"[^}]+default\\s*=\\s*\"([^\"]+)\"', '\\1') | first }}"
+
+    - name: Check if template name has changed
+      ansible.builtin.set_fact:
+        template_name_changed: "{{ current_template_name != new_template_name }}"
+
+    - name: Display template name status
+      ansible.builtin.debug:
+        msg: "Template name: {{ current_template_name }} -> {{ new_template_name }} ({{ 'changed' if template_name_changed else 'unchanged' }})"
+
+    - name: Update default_template_name in variables.tf
+      ansible.builtin.replace:
+        path: "{{ terraform_dir }}/variables.tf"
+        regexp: '(variable "default_template_name"[^}]+default\s*=\s*)"[^"]+"'
+        replace: '\1"{{ new_template_name }}"'
+      when: template_name_changed
+
+    - name: Display update result
+      ansible.builtin.debug:
+        msg: "Updated terraform/variables.tf with new template name: {{ new_template_name }}"
+      when: template_name_changed