extend cdist-type-emulator with singleton type

Signed-off-by: Nico Schottelius <nico@kr.ethz.ch>

bin/cdist-config

@@ -57,6 +57,7 @@ __cdist_abs_myname="$__cdist_abs_mydir/$__cdist_myname"
 : ${__cdist_name_parameter:=parameter}
 : ${__cdist_name_parameter_required:=required}
 : ${__cdist_name_parameter_optional:=optional}
+: ${__cdist_name_singleton:=singleton}
 : ${__cdist_name_target_host:=target_host}
 : ${__cdist_name_type:=type}
 : ${__cdist_name_type_bin:=type_bin}
@@ -162,11 +163,6 @@ __cdist_init_deploy()
    ln -sf "$__cdist_conf_dir" "$__cdist_local_base_dir/$__cdist_name_conf_dir"
 }
 
-# __cdist_cache_host()
-# {
-#    echo "${__cdist_cache_hosts}/${__cdist_target_host}"
-# }
-
 __cdist_type_has_explorer()
 {
    # We only create output, if there's at least one explorer
@@ -196,6 +192,11 @@ __cdist_type_gencode()
    echo "${__cdist_type_dir}/$1/${__cdist_name_gencode}"
 }
 
+__cdist_type_singleton()
+{
+   echo "${__cdist_type_dir}/$1/${__cdist_name_singleton}"
+}
+
 __cdist_type_parameter_dir()
 {
    echo "$(__cdist_type_dir "$1")/${__cdist_name_parameter}"

bin/cdist-type-emulator

@@ -25,12 +25,18 @@
 #
 
 . cdist-config
-[ $# -ge 1 ] || __cdist_usage "<id> <options>"
 set -eu
 
-__cdist_object_id="$1"; shift
+# Find out whether type is a singleton or regular type
 __cdist_type="$__cdist_myname"
 
+if [ -f "$(__cdist_type_singleton "$__cdist_type")" ]; then
+   __cdist_object_id="singleton"
+else
+   [ $# -ge 1 ] || __cdist_usage "<id> <options>"
+   __cdist_object_id="$1"; shift
+fi
+
 echo "$__cdist_object_id" | grep -q "^${__cdist_sane_regexp}\$" || \
    __cdist_usage "Insane object id, ${__cdist_object_id}."