add some commands to the live system

1 files changed, 55 insertions, 0 deletions

diff --git a/src/samizdat-daily-snapshot-root b/src/samizdat-daily-snapshot-root
new file mode 100755
index 0000000..c57524c
--- /dev/null
+++ b/src/samizdat-daily-snapshot-root
@@ -0,0 +1,55 @@
+#/bin/sh
+[ "$(id -u)" = 0 ] || exec sudo "$0" "$@" || exit
+
+is_subvol()
+{
+    btrfs subvolume show "$1" >/dev/null 2>&1
+}
+
+btrfs_subvolumes()
+{
+    btrfs subvolume list -a -t "${1:-/}" | awk '{print $4}' | sed -Ene 's?^(<FS_TREE>/)\?root/?/?p'
+}
+
+snapit()
+{
+    local dev mnt target
+
+    mnt=$(mktemp -d /tmp/mnt.XXXXXX) || return
+    src=$mnt/$1/
+    target=$mnt/${2:-daily/}${1%/}~$(date -I)
+    dev=$(btrfs fi sh / | sed -ne 's/.* path //p' | tail -n1) || return
+
+    mount "$dev" -o subvol=/ "$mnt"
+    if [ -e "$target" ]
+    then
+      :
+    else
+      mkdir -p "$(dirname "$target")"
+      btrfs subvolume snapshot -r "$src" "$target"
+    fi
+    umount "$mnt"
+    rmdir "$mnt"
+}
+
+do_not_snap()
+{
+  case "${1#/root/}" in
+    /var/cache/apt/archives|/home/*/.cache|/home/*/src/fsmgr/_build|/home/*/.stack|/home/*/.rustup)
+      true
+    ;;
+    *)
+      false
+    ;;
+  esac
+}
+
+snapit /root
+
+btrfs_subvolumes | while read f
+do
+    if is_subvol "$f"
+    then
+        do_not_snap "$f" || snapit /root/"${f#/}"
+    fi
+done