From 7262ae5ec6f63883c5e35318ecf06c6d68a62230 Mon Sep 17 00:00:00 2001
From: Tim Eertmoed <tim@eertmoed.de>
Date: Thu, 12 Dec 2024 19:32:44 +0100
Subject: [PATCH] sbin/overlayRoot.sh aktualisiert

---
 sbin/overlayRoot.sh  | 68 +++++++++++++++++++++++++++++++++++++
 usr/bin/overlayfs.sh | 80 --------------------------------------------
 2 files changed, 68 insertions(+), 80 deletions(-)
 create mode 100644 sbin/overlayRoot.sh
 delete mode 100644 usr/bin/overlayfs.sh

diff --git a/sbin/overlayRoot.sh b/sbin/overlayRoot.sh
new file mode 100644
index 0000000..440cf4f
--- /dev/null
+++ b/sbin/overlayRoot.sh
@@ -0,0 +1,68 @@
+#!/bin/bash
+
+#  This script will mount the root filesystem read-only and overlay it with a temporary tempfs
+#  Install:
+#  copy this script to /sbin/overlayRoot.sh and add "init=/sbin/overlayRoot.sh" to the cmdline.txt
+#  file in the raspbian image's boot partition.
+#  Execute the following commands as root:
+#  sudo dphys-swapfile swapoff
+#  sudo dphys-swapfile uninstall
+#  sudo update-rc.d dphys-swapfile remove
+#
+#  To install software, run upgrades and do other changes to the raspberry setup, simply remove the init=/sbin/overlayRoot.sh
+#  entry from the cmdline.txt file and reboot, make the changes, add the init= entry and reboot once more.
+
+set -e
+sleep 10
+fail() {
+    echo -e "$1" >&2
+    exit 1
+}
+
+# Prüfen und Modul laden
+modprobe overlay || fail "ERROR: OverlayFS-Modul nicht geladen."
+
+# /proc einbinden
+mountpoint -q /proc || mount -t proc proc /proc
+
+# Temporäres Dateisystem für Overlay erstellen
+mount -t tmpfs tmpfs /mnt || fail "ERROR: tmpfs konnte nicht gemountet werden."
+mkdir -p /mnt/lower /mnt/rw/upper /mnt/rw/work /mnt/newroot
+
+# Root-Dateisystem schreibgeschützt einbinden
+rootDev=$(awk '$2 == "/" {print $1}' /proc/mounts)
+rootMountOpt=$(awk '$2 == "/" {print $4}' /proc/mounts)
+rootFsType=$(awk '$2 == "/" {print $3}' /proc/mounts)
+
+mount -t "${rootFsType}" -o "${rootMountOpt},ro" "${rootDev}" /mnt/lower || \
+    fail "ERROR: Ursprüngliches Root-Dateisystem konnte nicht schreibgeschützt eingebunden werden."
+
+# OverlayFS einbinden
+mount -t overlay \
+    -o lowerdir=/mnt/lower,upperdir=/mnt/rw/upper,workdir=/mnt/rw/work \
+    overlay /mnt/newroot || fail "ERROR: OverlayFS konnte nicht gemountet werden."
+
+# Neue Root-Overlay-Verzeichnisse erstellen
+mkdir -p /mnt/newroot/ro /mnt/newroot/rw
+
+# Originale fstab modifizieren
+grep -v "$rootDev" /mnt/lower/etc/fstab > /mnt/newroot/etc/fstab
+cat <<EOF >> /mnt/newroot/etc/fstab
+# Das originale Root-Dateisystem wurde durch overlayRoot.sh entfernt.
+# Diese Änderung ist temporär. Die originale fstab ist in /ro/etc/fstab verfügbar.
+EOF
+
+# Root wechseln und alte Root aufräumen
+cd /mnt/newroot
+pivot_root . mnt || fail "ERROR: pivot_root fehlgeschlagen."
+
+exec chroot . /bin/bash -c "
+    mount --move /mnt/mnt/lower /ro || fail 'ERROR: /ro konnte nicht verschoben werden.'
+    mount --move /mnt/mnt/rw /rw || fail 'ERROR: /rw konnte nicht verschoben werden.'
+    umount /mnt/mnt || true
+    umount /mnt/proc || true
+    umount -l -f /mnt/dev || true
+    umount -l -f /mnt || true
+
+    exec /sbin/init
+"
diff --git a/usr/bin/overlayfs.sh b/usr/bin/overlayfs.sh
deleted file mode 100644
index dd26703..0000000
--- a/usr/bin/overlayfs.sh
+++ /dev/null
@@ -1,80 +0,0 @@
-#!/bin/sh
-# Raspberry Pi OverlayFS Initialization Script with NFS Logging
-# Version: 1.2
-
-set -e
-
-echo "Starting OverlayFS and NFS logging setup..."
-
-# Mount root filesystem as read-only
-mount -o remount,ro /
-
-# Start the DHCP client to get the hostname
-dhclient eth0 -1 # Wait for DHCP to complete
-
-# Get the hostname from DHCP
-DHCP_HOSTNAME=$(cat /var/lib/dhcp/dhclient.* | grep "option host-name" | awk '{print $3}' | tr -d '";')
-if [ -n "$DHCP_HOSTNAME" ]; then
-    echo "Setting hostname to $DHCP_HOSTNAME"
-    hostnamectl set-hostname "$DHCP_HOSTNAME"
-else
-    echo "No DHCP hostname found, using default hostname."
-    DHCP_HOSTNAME="default"
-fi
-
-# Set up OverlayFS for /tmp
-OVERLAY_BASE=/overlay
-mkdir -p ${OVERLAY_BASE}/{tmp_upper,tmp_work,varlog_work}
-
-# Mount /tmp as an overlay filesystem
-mkdir -p /tmp
-mount -t overlay overlay \
-  -o lowerdir=/tmp,upperdir=${OVERLAY_BASE}/tmp_upper,workdir=${OVERLAY_BASE}/tmp_work \
-  /tmp
-
-# Mount /var/log via NFS
-NFS_SERVER="192.168.12.239"
-NFS_PATH="/clients/$DHCP_HOSTNAME"
-LOCAL_MOUNT_POINT="/var/log"
-
-echo "Creating local mount point: $LOCAL_MOUNT_POINT"
-mkdir -p $LOCAL_MOUNT_POINT
-
-# Ensure NFS utilities are available
-if ! command -v mount.nfs > /dev/null; then
-    echo "NFS utilities not found! Installing nfs-common..."
-    sudo apt-get update
-    sudo apt-get install -y nfs-common
-fi
-
-echo "Mounting NFS: $NFS_SERVER:$NFS_PATH to $LOCAL_MOUNT_POINT"
-mount -t nfs "$NFS_SERVER:$NFS_PATH" $LOCAL_MOUNT_POINT || {
-    echo "NFS mount failed, using OverlayFS for /var/log."
-    # If NFS fails, use OverlayFS for /var/log
-    mkdir -p ${OVERLAY_BASE}/varlog_upper
-    mount -t overlay overlay \
-      -o lowerdir=/var/log,upperdir=${OVERLAY_BASE}/varlog_upper,workdir=${OVERLAY_BASE}/varlog_work \
-      /var/log
-}
-
-# Mount Chromium user data directory as an overlay
-mkdir -p /home/loginuser/.config/chromium
-mount -t overlay overlay \
-  -o lowerdir=/home/loginuser/.config/chromium,upperdir=${OVERLAY_BASE}/chromium_upper,workdir=${OVERLAY_BASE}/chromium_work \
-  /home/loginuser/.config/chromium
-
-# Fix permissions for loginuser
-chown -R loginuser:loginuser /home/loginuser/.config/chromium
-chmod 700 /home/loginuser/.config/chromium
-
-# Ensure that /var/log and /tmp are set up for the next boot
-echo "Adding NFS /var/log mount to /etc/fstab"
-if ! grep -q "$NFS_SERVER:$NFS_PATH" /etc/fstab; then
-    echo "$NFS_SERVER:$NFS_PATH $LOCAL_MOUNT_POINT nfs defaults 0 0" | sudo tee -a /etc/fstab
-fi
-
-echo "OverlayFS and NFS logging setup completed successfully."
-echo "Starting system..."
-
-# Continue with the regular boot process
-exec /sbin/init
\ No newline at end of file