Add waffle flags to migrations

src/registrar/models/waffle_flag.py

@@ -17,21 +17,45 @@ class WaffleFlag(AbstractUserFlag):
         verbose_name = "waffle flag"
         verbose_name_plural = "Waffle flags"
 
+    # Defines which waffle flags should be created at startup.
+    # Add to this list if you want to add another flag that is generated at startup.
+    # When you do so, you will need to add a new instance of `0091_create_waffle_flags_v{version_number}`
+    # in registrar/migrations for that change to update automatically on migrate.
+    DEFAULT_WAFFLE_FLAGS = [
+        "profile_feature",
+        "dns_hosting_feature"
+    ]
+
     @classmethod
-    def create_waffle_flags(cls):
+    def create_waffle_flags_for_migrations(cls):
         """
         Creates a pre-defined list of flags for our migrations.
         """
         logger.info("Creating default waffle flags...")
-        try:
-            # Flags can be activated through the command line or through django admin.
-            # To keep the scope of this function minimal and simple, if we require additional
-            # config on these flag, it should be done in a seperate function or as a command.
-            flag_names = [
-                "profile_feature",
-                "dns_hosting_feature",
-            ]
-            flags = [cls(name=flag_name) for flag_name in flag_names]
-            cls.objects.bulk_create(flags)
-        except Exception as e:
-            logger.error(f"An error occurred when attempting to create WaffleFlags: {e}")
+        # Flags can be changed through the command line or through django admin.
+        # To keep the scope of this function minimal and simple, if we require additional
+        # config on these flag, it should be done in a seperate function or as a command.
+        for flag_name in cls.DEFAULT_WAFFLE_FLAGS:
+            try:
+                cls.objects.update_or_create(
+                    name=flag_name,
+                    # Booleans like superusers or is_staff can be set here, if needed.
+                    defaults={
+                        'note': 'Auto-generated waffle flag'
+                    }
+                )
+            except Exception as e:
+                logger.error(f"An error occurred when attempting to add or update flag {flag_name}: {e}")
+    
+    @classmethod
+    def delete_waffle_flags_for_migrations(cls):
+        """
+        Delete a pre-defined list of flags for our migrations (the reverse_code operation).
+        """
+        logger.info("Deleting default waffle flags...")
+        existing_flags = cls.objects.filter(name__in=cls.DEFAULT_WAFFLE_FLAGS)
+        for flag in existing_flags:
+            try:
+                cls.objects.get(name=flag.name).delete()
+            except Exception as e:
+                logger.error(f"An error occurred when attempting to delete flag {flag.name}: {e}")