[__lxc_container] better support config modifications at creation time

When a container is created, the configuration is unknown to the
explorer. To do the job without the knowleage, following is added: If
the container will be created, it adds all absent configuration options
to be deleted. Because it do not know which configuration options exist,
it tries to remove all if there exists.

This behaviour is extended for containers that will be cloned: Because
the container who will be cloned is known and it will copy the config
nearly one to one, so it will read this configuration.

The removal of configuration is generally improved by generating a
pattern to ignore spaces at the beginning, near the equal sign and at
the end. This deletes the correct configuration lines even they have
malformed whitespaces.

cdist/conf/type/__lxc_container/diff-conf-changes.sh

@@ -46,9 +46,13 @@ trimm_whitespaces() {
 }
 
 
+# save states
+state_should="$(cat "$__object/parameter/state")"
+state_is="$(cat "$__object/explorer/state")"
+
 # Only required if container will not be absent
 # prepare the wanted configuration lines
-if [ "$(cat "$__object/parameter/state")" != "absent" ]; then
+if [ "$state_should" != "absent" ]; then
 	# create the files directory
 	mkdir "$__object/files/"
 
@@ -69,4 +73,13 @@ if [ "$(cat "$__object/parameter/state")" != "absent" ]; then
 	# config.del
 	grep -f "$__object/explorer/config" \
 		"$__object/files/config-absent" > "$__object/files/config.del" || true
+
+
+	# fallback: if template parameter exists and container currently absent; try to remove all configs
+	#  If the container is currently absent, nothing will be removed, even it's in the default config
+	#  In this case, it will try to delete every configuration option to be sure
+	# only the cloning configuration is known, but not if the container will be created in an other way
+	if [ "$state_is" = "absent" ] && ! [ -f "$__object/parameter/clone" ]; then
+		cp "$__object/files/config-absent" "$__object/files/config.del"
+	fi
 fi

cdist/conf/type/__lxc_container/explorer/config

@@ -22,8 +22,24 @@ else
 fi
 
 
-# assemble the container configuration file
-config="$lxcpath/$name/config"
+# if the container will be cloned, use the configuration of the container to clone from
+# else, just use the normal container configuration
+clone="$__object/parameter/clone"
+if [ -f "$clone" ] && [ "$("$__type_explorer/state")" = "absent" ]; then
+	clone="$(cat "$clone")"
+	clonepath="$__object/parameter/clonepath"
+	if [ -f "$clonepath" ]; then
+		clonepath="$(cat "$clonepath")"
+	else
+		clonepath="$lxcpath"
+	fi
+
+	# set the config path of the container to clone from
+	config="$clonepath/$clone/config"
+else
+	# assemble the configuration file of the container
+	config="$lxcpath/$name/config"
+fi
 
 # check if the file exist, else the container is absent
 if [ -r "$config" ]; then

cdist/conf/type/__lxc_container/gencode-remote

@@ -205,10 +205,14 @@ DONE
 	# check if smth. to be deleted
 	#  must be before adding, because it takes the content of the original file
 	#  because 'cat $file > $file' will not work (> opens before command reads it)
+	# will create extended regex pattern for grep with malformed spaces
 	if [ -s "$__object/files/config.del" ]; then
 		cat <<DONE
-grep -v -f - <<'ABSENT' "$container_config" > "\$tmpconfig"
-$(cat "$__object/files/config.del")
+grep -v -E -f - <<'ABSENT' "$container_config" > "\$tmpconfig"
+$(awk -v FS=' = ' -v OFS=' = ' -v blank='[[:blank:]]*' '
+function ntostring(n) { ret=""; for(i=n; i<=NF; i++) ret=ret $i (i<NF ? OFS : ""); return ret }
+{ printf "^%s%s%s=%s%s%s$%s", blank, $1, blank, blank, ntostring(2), blank, ORS }
+	' "$__object/files/config.del" )
 ABSENT
 DONE
 	fi