Automatically generate cloud disk image when updating domains configuration

virtweb_backend/src/constants.rs

@@ -57,6 +57,9 @@ pub const DISK_SIZE_MIN: FileSize = FileSize::from_mb(50);
 /// Disk size max (B)
 pub const DISK_SIZE_MAX: FileSize = FileSize::from_gb(20000);
 
+/// Cloud init generated disk image prefix
+pub const CLOUD_INIT_IMAGE_PREFIX_NAME: &str = "virtweb-cloudinit-autogen-image";
+
 /// Net nat entry comment max size
 pub const NET_NAT_COMMENT_MAX_SIZE: usize = 250;