Extend admin UI to allow restoring previous config revisions

netbox/extras/admin.py

@@ -1,5 +1,10 @@
 from django.contrib import admin
+from django.shortcuts import get_object_or_404, redirect
+from django.template.response import TemplateResponse
+from django.urls import path, reverse
+from django.utils.html import format_html
 
+from netbox.config import get_config, PARAMS
 from .forms import ConfigRevisionForm
 from .models import ConfigRevision, JobResult
 
@@ -33,7 +38,7 @@ class ConfigRevisionAdmin(admin.ModelAdmin):
         })
     ]
     form = ConfigRevisionForm
-    list_display = ('id', 'is_active', 'created', 'comment')
+    list_display = ('id', 'is_active', 'created', 'comment', 'restore_link')
     ordering = ('-id',)
     readonly_fields = ('data',)
 
@@ -47,6 +52,8 @@ class ConfigRevisionAdmin(admin.ModelAdmin):
 
         return initial
 
+    # Permissions
+
     def has_add_permission(self, request):
         # Only superusers may modify the configuration.
         return request.user.is_superuser
@@ -61,6 +68,58 @@ class ConfigRevisionAdmin(admin.ModelAdmin):
             obj is None or not obj.is_active()
         )
 
+    # List display methods
+
+    def restore_link(self, obj):
+        if obj.is_active():
+            return ''
+        return format_html(
+            '<a href="{url}" class="button">Restore</a>',
+            url=reverse('admin:extras_configrevision_restore', args=(obj.pk,))
+        )
+    restore_link.short_description = "Actions"
+
+    # URLs
+
+    def get_urls(self):
+        urls = [
+            path('<int:pk>/restore/', self.admin_site.admin_view(self.restore), name='extras_configrevision_restore'),
+        ]
+
+        return urls + super().get_urls()
+
+    # Views
+
+    def restore(self, request, pk):
+        # Get the ConfigRevision being restored
+        candidate_config = get_object_or_404(ConfigRevision, pk=pk)
+
+        if request.method == 'POST':
+            candidate_config.activate()
+            self.message_user(request, f"Restored configuration revision #{pk}")
+
+            return redirect(reverse('admin:extras_configrevision_changelist'))
+
+        # Get the current ConfigRevision
+        config_version = get_config().version
+        current_config = ConfigRevision.objects.filter(pk=config_version).first()
+
+        params = []
+        for param in PARAMS:
+            params.append((
+                param.name,
+                current_config.data.get(param.name, None),
+                candidate_config.data.get(param.name, None)
+            ))
+
+        context = self.admin_site.each_context(request)
+        context.update({
+            'object': candidate_config,
+            'params': params,
+        })
+
+        return TemplateResponse(request, 'admin/extras/configrevision/restore.html', context)
+
 
 #
 # Reports & scripts