X-Git-Url: https://git.grml.org/?p=grml-rescueboot.git;a=blobdiff_plain;f=debian%2Fpostinst;h=d5f9b750bf5dfd21e7c581f6c68ca935896ba694;hp=eb3a28dcf5d31448ce6b6e3075aaca63f6d332d4;hb=395abc5bda9903f9bbe0ecd1df63a59bdb6b0071;hpb=199476a3ee4fb6e6e4e71f719c9f29f5fa93cf5d

diff --git a/debian/postinst b/debian/postinst
index eb3a28d..d5f9b75 100644
--- a/debian/postinst
+++ b/debian/postinst
@@ -3,19 +3,39 @@
 
 set -e
 
+update_grub_wrapper() {
+  # default, unless configured otherwise:
+  ISO_LOCATION=/boot/grml
+
+  if [ -r /etc/default/grml-rescueboot ] ; then
+    . /etc/default/grml-rescueboot
+  fi
+
+  if ! ls "${ISO_LOCATION}"/*iso >/dev/null 2>&1 ; then
+    echo "INFO: No *.iso files found inside ${ISO_LOCATION}."
+    echo "INFO: Please create ${ISO_LOCATION} and place rescue ISO(s) there."
+    echo "INFO: Finally invoke update-grub and enjoy your rescue system."
+    return 0
+  fi
+
+  if ! which update-grub >/dev/null 2>&1; then
+    echo "WARN: ISOs found inside ${ISO_LOCATION} but update-grub not present (huh?)"
+    return 0
+  fi
+
+  if ! [ -e /boot/grub/grub.cfg ] ; then
+    echo "WARN: ISOs found inside ${ISO_LOCATION} but /boot/grub/grub.cfg does not exist."
+    echo "WARN: Ignoring request to run update-grub to avoid possible boot loader problems."
+    return 0
+  fi
+
+  echo "INFO: ISOs found inside ${ISO_LOCATION}, invoking update-grub:"
+  update-grub
+}
+
 case "$1" in
     configure)
-      if ls /boot/grml/*iso >/dev/null 2>&1 ; then
-	if which update-grub >/dev/null 2>&1; then
-	  echo "ISOs found inside /boot/grml, invoking update-grub:"
-          update-grub
-	else
-	  echo "WARN: ISOs found inside /boot/grml but update-grub not present (huh?)"
-        fi
-      else
-	echo "No *.iso files found inside /boot/grml/. Please create /boot/grml and"
-	echo "place Grml ISO(s) there. Finally invoke update-grub and enjoy your rescue system."
-      fi
+      update_grub_wrapper
     ;;
 
     abort-upgrade|abort-remove|abort-deconfigure)