Adds config template to vm model (#13450)

* adds config template to vm model #12461

* Add translation tags; collapse config data

* i18n cleanup

* Establish parity with DeviceRenderConfigView

* Move config_template field to RenderConfigMixin

---------

Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>

netbox/virtualization/views.py

@@ -1,11 +1,14 @@
+import traceback
 from collections import defaultdict
 
 from django.contrib import messages
 from django.db import transaction
 from django.db.models import Prefetch, Sum
+from django.http import HttpResponse
 from django.shortcuts import get_object_or_404, redirect, render
 from django.urls import reverse
 from django.utils.translation import gettext as _
+from jinja2.exceptions import TemplateError
 
 from dcim.filtersets import DeviceFilterSet
 from dcim.models import Device
@@ -389,6 +392,55 @@ class VirtualMachineConfigContextView(ObjectConfigContextView):
     )
 
 
+@register_model_view(VirtualMachine, 'render-config')
+class VirtualMachineRenderConfigView(generic.ObjectView):
+    queryset = VirtualMachine.objects.all()
+    template_name = 'virtualization/virtualmachine/render_config.html'
+    tab = ViewTab(
+        label=_('Render Config'),
+        permission='extras.view_configtemplate',
+        weight=2100
+    )
+
+    def get(self, request, **kwargs):
+        instance = self.get_object(**kwargs)
+        context = self.get_extra_context(request, instance)
+
+        # If a direct export has been requested, return the rendered template content as a
+        # downloadable file.
+        if request.GET.get('export'):
+            response = HttpResponse(context['rendered_config'], content_type='text')
+            filename = f"{instance.name or 'config'}.txt"
+            response['Content-Disposition'] = f'attachment; filename="{filename}"'
+            return response
+
+        return render(request, self.get_template_name(), {
+            'object': instance,
+            'tab': self.tab,
+            **context,
+        })
+
+    def get_extra_context(self, request, instance):
+        # Compile context data
+        context_data = instance.get_config_context()
+        context_data.update({'virtualmachine': instance})
+
+        # Render the config template
+        rendered_config = None
+        if config_template := instance.get_config_template():
+            try:
+                rendered_config = config_template.render(context=context_data)
+            except TemplateError as e:
+                messages.error(request, f"An error occurred while rendering the template: {e}")
+                rendered_config = traceback.format_exc()
+
+        return {
+            'config_template': config_template,
+            'context_data': context_data,
+            'rendered_config': rendered_config,
+        }
+
+
 @register_model_view(VirtualMachine, 'edit')
 class VirtualMachineEditView(generic.ObjectEditView):
     queryset = VirtualMachine.objects.all()