__locale: add state explorer

.. so it doesn't execute code all the time.

cdist/conf/type/__locale/explorer/state

@@ -0,0 +1,36 @@
+#!/bin/sh -e
+# __locale/explorer/state
+#
+# 2020 Matthias Stecher (matthiasstecher at gmx.de)
+#
+# 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/>.
+#
+#
+# Check if the locale is already installed on the system.
+# Outputs 'present' or 'absent' depending if the locale exists.
+#
+
+
+# Get user-defined locale
+# locale name is echoed differently than the user propably set it (for UTF-8)
+locale="$(echo "$__object_id" | sed 's/UTF-8/utf8/')"
+
+# Check if the given locale exists on the system
+if localedef --list-archive | grep -qFx "$locale"; then
+    echo present
+else
+    echo absent
+fi

cdist/conf/type/__locale/gencode-remote

@@ -23,6 +23,15 @@
 
 locale="$__object_id"
 
+state_is=$(cat "$__object/explorer/state")
+state_should=$(cat "$__object/parameter/state")
+
+# short circuit if there is nothing to do
+if [ "$state_is" = "$state_should" ]; then
+    exit 0
+fi
+
+
 # Hardcoded, create a pull request with
 # branching on $os in case it is at another location
 alias=/usr/share/locale/locale.alias
@@ -35,8 +44,6 @@ charmap=$(echo "$locale" | cut -d . -f 2)
 # W-T-F!
 locale_remove=$(echo "$locale" | sed 's/UTF-8/utf8/')
 
-state=$(cat "$__object/parameter/state")
-
 os=$(cat "$__global/explorer/os")
 
 # Nothing to be done on alpine
@@ -46,7 +53,7 @@ case "$os" in
         ;;
 esac
 
-case "$state" in
+case "$state_should" in
     present)
         echo localedef -A "$alias" -f "$charmap" -i "$input" "$locale"
     ;;
@@ -54,7 +61,7 @@ case "$state" in
         echo localedef --delete-from-archive "$locale_remove"
     ;;
     *)
-        echo "Unsupported state: $state" >&2
+        echo "Unsupported state: $state_should" >&2
         exit 1
     ;;
 esac