Rework resolv.conf handling, error out on wrong symlinks. [Closes: issue984]

[grml-live.git] / etc / grml / fai / config / hooks / instsoft.GRMLBASE

diff --git a/etc/grml/fai/config/hooks/instsoft.GRMLBASE b/etc/grml/fai/config/hooks/instsoft.GRMLBASE
index c8150be..cf8c3be 100755 (executable)
--- a/etc/grml/fai/config/hooks/instsoft.GRMLBASE
+++ b/etc/grml/fai/config/hooks/instsoft.GRMLBASE
@@ -21,11 +21,24 @@ 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