Rework resolv.conf handling, error out on wrong symlinks. [Closes: issue984]
[grml-live.git] / etc / grml / fai / config / hooks / instsoft.GRMLBASE
index 5dc3433..cf8c3be 100755 (executable)
@@ -9,15 +9,36 @@
 set -u
 set -e
 
+# if hooks/updatebase.GRMLBASE fails for whatever reason
+# and can't skip instsoft.GRMLBASE we have to make sure
+# we exit here as well
+if [ -n "$BUILD_ONLY" ] ; then
+   "Exiting hooks/instsoft.GRMLBASE as BUILD_ONLY environment is set."
+   exit 0
+fi
+
 if [ "$FAI_ACTION" = "softupdate" ] ; then
    echo "Action $FAI_ACTION of FAI (hooks/instsoft.GRMLBASE) via grml-live running"
 
    if [ -r /etc/resolv.conf ] ; then
-      if [ -r $target/etc/resolvconf/run/resolv.conf ] ; then
+     if [ -d $target/etc/resolvconf/run ] ; then # resolvconf
+       # sanity check to avoid "input file is output file",
+       # see http://bts.grml.org/grml/issue984
+       if ! [ -L $target/etc/resolvconf/run/resolv.conf ] ; then
          cat /etc/resolv.conf >> $target/etc/resolvconf/run/resolv.conf
-      else
+       else
+         echo "Error: /etc/resolvconf/run/resolv.conf in chroot should not be a symlink." >&2
+         echo "       Looks like something is wrong, please fix manually." >&2
+         exit 1
+       fi
+     else # no resolvconf installed in chroot
+       if ! [ -L $target/etc/resolv.conf ] ; then
          cat /etc/resolv.conf >> $target/etc/resolv.conf
-      fi
+       else
+         echo "Error: /etc/resolv.conf in chroot should not be a symlink (resolvconf not installed)." >&2
+         exit 1
+       fi
+     fi
    fi
 
    if [ -r $target/etc/policy-rc.d.conf ] ; then