From 6ca4256b3e724155b9aea87b5f8c747784acc56e Mon Sep 17 00:00:00 2001
From: cyteen <cyteen@ring-zero.co.uk>
Date: Wed, 11 Mar 2026 02:15:45 +0000
Subject: [PATCH] Adds apt hooks to create a snapshot before operations.

---
 020_zfs-apt-snapshot.sh | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/020_zfs-apt-snapshot.sh b/020_zfs-apt-snapshot.sh
index f6429e7..864d03d 100644
--- a/020_zfs-apt-snapshot.sh
+++ b/020_zfs-apt-snapshot.sh
@@ -1,6 +1,13 @@
 #!/usr/bin/env bash
 
-POOL_NAME=rpool
+ROOT_DATASET=$(zfs list -H -o name,mountpoint | awk '$2 == "/" { print $1 }')
+if [ -z "$ROOT_DATASET" ]; then
+  echo "Error: Could not detect ZFS dataset mounted at /" >&2
+  exit 1
+fi
+
+# Usually the pool name is the first component (rpool/ROOT/ubuntu → rpool)
+POOL_NAME="${ROOT_DATASET%%/*}"
 
 #  Create zfs snapshots before apt operations using apt hooks
 
@@ -9,8 +16,8 @@ POOL_NAME=rpool
 conf_print_snapPrepApt() {
   cat <<EOF
   #!/bin/bash
-DATE="'$(date +%F-%T)'"
-zfs snapshot -r ${POOL_NAME}@snap_pre_apt_$DATE
+DATE="\$(date +%F-%T)"
+zfs snapshot -r ${POOL_NAME}@snap_pre_apt_\$DATE
 EOF
 }
 conf_print_snapPrepApt | sudo tee /usr/local/sbin/snapPrepApt
@@ -24,15 +31,14 @@ DPkg::Pre-Invoke {"/usr/local/sbin/snapPrepApt || true";};
 EOF
 }
 conf_print_apt_conf_d | sudo tee /etc/apt/apt.conf.d/90zfs-pre-apt-snapshot
-sudo chmod +x /etc/apt/apt.conf.d/90zfs-pre-apt-snapshot
 
 # 3. Kernel Updates
 # Use /etc/kernel/preinst.d/ to snapshot before kernel installation:
 conf_print_kernel_preinst_d() {
   cat <<EOF
 #!/bin/bash
-DATE='$(date +%F-%T)'
-zfs snapshot -r ${POOL_NAME}@pre-kernel_${DATE}
+DATE="\$(date +%F-%T)"
+zfs snapshot -r \${POOL_NAME}@pre-kernel_\${DATE}
 EOF
 }
 conf_print_kernel_preinst_d | sudo tee /etc/kernel/preinst.d/90zfs-pre-kernel-snapshot