backport __install_partition_msdos from Steven

Signed-off-by: Nico Schottelius <nico@feder.schottelius.org>

cdist/conf/type/__install_partition_msdos/man.rst

@@ -19,6 +19,12 @@ type
 
 OPTIONAL PARAMETERS
 -------------------
+device
+   the device we're working on. Defaults to the string prefix of --partition
+
+minor
+   the partition number we're working on. Defaults to the numeric suffix of --partition
+
 partition
    defaults to object_id
 
@@ -49,6 +55,8 @@ EXAMPLES
     __install_partition_msdos /dev/sda6 --type 83 --size 50%
     # rest of the extended partition, linux
     __install_partition_msdos /dev/sda7 --type 83 --size +
+    # nvm device partition 2
+    __install_partition_msdos /dev/nvme0n1p2 --device /dev/nvme0n1 --minor 2 --type 83 --size 128M --bootable true
 
 
 AUTHORS
@@ -58,7 +66,7 @@ Steven Armstrong <steven-cdist--@--armstrong.cc>
 
 COPYING
 -------
-Copyright \(C) 2011 Steven Armstrong. You can redistribute it
+Copyright \(C) 2011-2017 Steven Armstrong. 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/conf/type/__install_partition_msdos/manifest

@@ -25,10 +25,15 @@ else
    partition="/$__object_id"
    echo "$partition" > "$__object/parameter/partition"
 fi
-device="$(echo "$partition" | sed 's/[0-9]//g')"
-echo "$device" > "$__object/parameter/device"
-minor="$(echo "$partition" | sed 's/[^0-9]//g')"
-echo "$minor" > "$__object/parameter/minor"
+
+if [ ! -f "$__object/parameter/device" ]; then
+   device="$(echo "$partition" | sed 's/[0-9]//g')"
+   echo "$device" > "$__object/parameter/device"
+fi
+if [ ! -f "$__object/parameter/minor" ]; then
+   minor="$(echo "$partition" | sed 's/[^0-9]//g')"
+   echo "$minor" > "$__object/parameter/minor"
+fi
 
 if [ ! -f "$__object/parameter/bootable" ]; then
    echo "false" > "$__object/parameter/bootable"

cdist/conf/type/__install_partition_msdos/parameter/optional

@@ -1,3 +1,5 @@
+device
+minor
 partition
 bootable
 size