Stop Umbrel if external storage device is unreliable (#224)

Co-authored-by: Luke Childs <lukechilds123@gmail.com>

scripts/umbrel-os/external-storage/monitor

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+UMBREL_ROOT="$(readlink -f $(dirname "${BASH_SOURCE[0]}")/../../..)"
+block_device="${1}"
+mount_point="${2}"
+
+check_if_not_already_running() {
+  if ps ax | grep $0 | grep -v $$ | grep bash | grep -v grep
+  then
+    echo "storage monitor is already running"
+    exit 1
+  fi
+}
+
+main () {
+  check_if_not_already_running
+
+  while true; do
+    if ! [[ -e "/dev/${block_device}" ]]; then
+      echo "Mounted block device no longer exists!"
+      break
+    fi
+
+    if ! grep --quiet " ${mount_point} " /proc/mounts; then
+      echo "External storage is no longer mounted!"
+      break
+    fi
+
+    if grep " ${mount_point} " /proc/mounts | grep --quiet '[ ,]ro[ ,]'; then
+      echo "External storage is mounted as read only!"
+      break
+    fi
+
+    if ! df -h "${UMBREL_ROOT}" | grep --quiet "/dev/${block_device}"; then
+      echo "Umbrel root is no longer bind mounted to external storage!"
+      break
+    fi
+
+    sleep 1
+  done
+
+  echo "Stopping Umbrel due to failed storage device check..."
+  docker kill $(docker ps -aq)
+}
+
+main

scripts/umbrel-os/external-storage/mount

@@ -203,6 +203,10 @@ main () {
   echo "Checking SD Card root is bind mounted at /sd-root..."
   df -h "/sd-root${UMBREL_ROOT}" | grep --quiet "/dev/root"
 
+  echo "Starting external drive mount monitor..."
+  echo
+  ${UMBREL_ROOT}/scripts/umbrel-os/external-storage/monitor ${block_device} ${MOUNT_POINT} &
+
   echo "Mount script completed successfully!"
 }