ovpn_copy_server_files: Copy files without rsync

* Hack around the missing rsync by using tar to preserve the directory
  structure.
* Fixes #73

bin/ovpn_copy_server_files

@@ -2,6 +2,8 @@
 ## @licence MIT <http://opensource.org/licenses/MIT>
 ## @author Copyright (C) 2015 Robin Schneider <ypid@riseup.net>
 
+set -e
+
 if [ -z "$OPENVPN" ]; then
     export OPENVPN="$PWD"
 fi
@@ -10,27 +12,30 @@ if ! source "$OPENVPN/ovpn_env.sh"; then
     exit 1
 fi
 
-TARGET="/tmp/openvpn_${OVPN_CN}"
+TARGET="$OPENVPN/server"
 if [ -n "$1" ]; then
     TARGET="$1"
-else
-    TARGET="$OPENVPN/server"
 fi
+mkdir -p "${TARGET}"
 
 ## Ensure that no other keys then the one for the server is present.
 rm --recursive --force "$TARGET/pki/private" "$TARGET/pki/issued"
 
-echo "
-openvpn.conf
-ovpn_env.sh
-pki/private/${OVPN_CN}.key
-pki/issued/${OVPN_CN}.crt
-pki/dh.pem
-pki/ta.key
-pki/ca.crt
-" | rsync --recursive --verbose \
-    --files-from - \
-    "$OPENVPN/" "$TARGET"
+FILES=(
+    "openvpn.conf"
+    "ovpn_env.sh"
+    "pki/private/${OVPN_CN}.key"
+    "pki/issued/${OVPN_CN}.crt"
+    "pki/dh.pem"
+    "pki/ta.key"
+    "pki/ca.crt"
+)
+
+# rsync isn't available to keep size down
+# cp --parents isn't in busybox version
+# hack the directory structure with tar
+tar cf - -C "${OPENVPN}" "${FILES[@]}" | tar xvf - -C "${TARGET}"
+
 mkdir -p "$TARGET/ccd"
 
 echo "Created the openvpn configuration for the server: $TARGET"