[__hostname] Support all systemd OSes and prefer hostnamectl

cdist/conf/type/__hostname/explorer/hostname

@@ -0,0 +1,48 @@
+#!/bin/sh
+#
+# 2019 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
+#
+# 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/>.
+#
+#
+# Retrieve the running hostname
+#
+
+# Firstly, check hostnamectl if available.
+if command -v hostnamectl >/dev/null
+then
+    hostnamectl --static && exit 0
+fi
+
+
+# Almost any distribution
+if [ -f /etc/hostname ]; then
+    cat /etc/hostname
+# SuSE
+elif [ -f /etc/HOSTNAME ]; then
+    cat /etc/HOSTNAME
+# OpenBSD
+elif [ -f /etc/myname ]; then
+    cat /etc/myname
+# FreeBSD
+elif [ "$(uname -s)" == FreeBSD ]; then
+    (. /etc/rc.conf && echo $hostname)
+# Mac OS X
+elif [ "$(uname -s)" == Darwin -a -f "$(command -v scutil)" ]; then
+    scutil --get HostName 2>/dev/null || hostname -s
+else
+    command -v hostname && hostname -s
+fi

cdist/conf/type/__hostname/gencode-remote

@@ -2,6 +2,7 @@
 #
 # 2014-2017 Steven Armstrong (steven-cdist at armstrong.cc)
 # 2014 Nico Schottelius (nico-cdist at schottelius.org)
+# 2019 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
 #
 # This file is part of cdist.
 #
@@ -46,8 +47,9 @@ case "$os" in
         fi
     ;;
     *)
-        echo "Unsupported os: $os" >&2
+        if [ "$name_running" -a "$name_running" = "$name_should" ]; then
-        exit 1
+            exit 0
+        fi
     ;;
 esac
 
@@ -56,23 +58,35 @@ esac
 #
 echo changed >> "$__messages_out"
 
-# Use the good old way to set the hostname even on machines running systemd.
+
+# First try to set the hostname using hostnamectl, if available.
+if [ "$has_hostnamectl" ]; then
+    # Allow hostnamectl to fail silently.
+    # Who the fuck invented a tool that needs dbus to set the hostname anyway ...
+
+    cat <<EOF
+if hostnamectl set-hostname '$name_should'; then
+    printf '%s\\n' '$name_should' > /etc/hostname
+    exit 0
+fi
+EOF
+fi
+
+# Use the good old way to set the hostname. Also if hostnamectl fails.
 case "$os" in
     archlinux|debian|ubuntu|devuan|centos|coreos|alpine)
         printf "printf '%%s\\\\n' '$name_should' > /etc/hostname\\n"
         echo "hostname -F /etc/hostname"
     ;;
     freebsd|openbsd)
+        # NOTE: Writing the hostname to file is done in the manifest.
         echo "hostname '$name_should'"
     ;;
     suse)
         echo "hostname '$name_should'"
         printf "printf '%%s\\\\n' '$name_should' > /etc/HOSTNAME\\n"
     ;;
+    *)
+        echo "echo 'Unsupported OS: $os' >&2; exit 1"
+    ;;
 esac
-
-if [ "$has_hostnamectl" ]; then
-    # Allow hostnamectl set-hostname to fail silently.
-    # Who the fuck invented a tool that needs dbus to set the hostname anyway ...
-    echo "hostnamectl set-hostname '$name_should' || true"
-fi

cdist/conf/type/__hostname/manifest

@@ -2,6 +2,7 @@
 #
 # 2012 Steven Armstrong (steven-cdist at armstrong.cc)
 # 2014 Nico Schottelius (nico-cdist at schottelius.org)
+# 2019 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
 #
 # This file is part of cdist.
 #
@@ -63,6 +64,7 @@ case "$os" in
         echo "$name_should" | __file /etc/myname --source -
     ;;
     *)
-        not_supported
+        # On other operating systems we fall back to hostnamectl if available…
+        test -n "$(cat "$__object/explorer/has_hostnamectl")" || not_supported
     ;;
 esac