diff --git a/.container b/.container
new file mode 100644
index 0000000..8fc6fe9
--- /dev/null
+++ b/.container
@@ -0,0 +1 @@
+ghcr.io/gardenlinux/repo-debian-snapshot@sha256:6ef03c0904ddff4485d33a430caf4f3919d14ef26e56d248a923961855c36570
diff --git a/prepare_source b/prepare_source
index 07f7094..d856d7d 100755
--- a/prepare_source
+++ b/prepare_source
@@ -1,7 +1 @@
-apt-get -y update && apt-get -yqq install dpkg-source-gitarchive pristine-lfs
-set -x
-git clone --recurse-submodules https://salsa.debian.org/cloud-team/google-guest-agent.git $dir/src
-cd $dir/src
-pristine-lfs checkout -o .. --auto
-mv ../google-guest-agent_20211116.00.orig.tar.xz ../orig.tar.xz
-xz -d ../orig.tar.xz
+apt_src google-guest-agent