need to pass a known suffix from outside

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>

cdist/conf/type/__chroot_mount/gencode-local

@@ -21,8 +21,9 @@
 chroot="/$__object_id"
 
 if [ -f "$__object/parameter/manage-resolv-conf" ]; then
+   suffix="$(cat "$__object/parameter/manage-resolv-conf")"
    resolv_conf="${chroot}/etc/resolv.conf"
-   original_resolv_conf="${resolv_conf}${__cdist_object_marker}"
+   original_resolv_conf="${resolv_conf}.${suffix}"
    cat << DONE
 $__remote_exec $__target_host << EOSSH
 if [ -f "${resolv_conf}" ]; then

cdist/conf/type/__chroot_mount/man.rst

@@ -18,13 +18,17 @@ None
 
 OPTIONAL PARAMETERS
 -------------------
-None
+manage-resolv-conf
+    manage /etc/resolv.conf inside the chroot.
+    Use the value of this parameter as the suffix to save a copy
+    of the current /etc/resolv.conf to /etc/resolv.conf.$suffix.
+    This is used by the __chroot_umount type to restore the initial
+    file content when unmounting the chroot.
 
 
 BOOLEAN PARAMETERS
 ------------------
-manage-resolv-conf
-    manage /etc/resolv.conf inside the chroot
+None.
 
 
 EXAMPLES
@@ -34,6 +38,9 @@ EXAMPLES
 
     __chroot_mount /path/to/chroot
 
+    __chroot_mount /path/to/chroot \
+      --manage-resolv-conf "some-known-string"
+
 
 AUTHORS
 -------

cdist/conf/type/__chroot_umount/gencode-local

@@ -21,8 +21,9 @@
 chroot="/$__object_id"
 
 if [ -f "$__object/parameter/manage-resolv-conf" ]; then
+   suffix="$(cat "$__object/parameter/manage-resolv-conf")"
    resolv_conf="${chroot}/etc/resolv.conf"
-   original_resolv_conf="${resolv_conf}${__cdist_object_marker}"
+   original_resolv_conf="${resolv_conf}.${suffix}"
 cat << DONE
 $__remote_exec $__target_host << EOSSH
 if [ -f "${original_resolv_conf}" ]; then

cdist/conf/type/__chroot_umount/man.rst

@@ -18,13 +18,17 @@ None
 
 OPTIONAL PARAMETERS
 -------------------
-None
+manage-resolv-conf
+    manage /etc/resolv.conf inside the chroot.
+    Use the value of this parameter as the suffix to find the backup file
+    that was saved by the __chroot_mount.
+    This is used by the to restore the initial file content when unmounting
+    the chroot.
 
 
 BOOLEAN PARAMETERS
 ------------------
-manage-resolv-conf
-    manage /etc/resolv.conf inside the chroot
+None.
 
 
 EXAMPLES
@@ -34,6 +38,9 @@ EXAMPLES
 
     __chroot_umount /path/to/chroot
 
+    __chroot_umount /path/to/chroot \
+      --manage-resolv-conf "some-known-string"
+
 
 SEE ALSO
 --------

cdist/conf/type/__chroot_umount/manifest

@@ -0,0 +1,36 @@
+#!/bin/sh
+#
+# 2016 Steven Armstrong (steven-cdist at armstrong.cc)
+#
+# This file is part of cdist.
+#
+# cdist is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+
+chroot="/$__object_id"
+
+if [ -f "$__object/parameter/manage-resolv-conf" ]; then
+   suffix="$(cat "$__object/parameter/manage-resolv-conf")"
+   resolv_conf="${chroot}/etc/resolv.conf"
+   original_resolv_conf="${resolv_conf}.${suffix}"
+cat << DONE
+$__remote_exec $__target_host << EOSSH
+if [ -f "${original_resolv_conf}" ]; then
+   # restore original /etc/resolv.conf that we moved out of the way
+   # in __chroot_mount/gencode-local
+   mv -f "${original_resolv_conf}" "${resolv_conf}"
+fi
+EOSSH
+DONE
+fi