[directory-size.sh] Support spaces in paths (#239)

The current code emits directory label only up to the first space, due
to the default behavior of `awk`. This change pulls in the rest of the
line output from `du` into the label, so directories containing spaces
are properly captured

---------

Signed-off-by: Andrew Roberts <adroberts@gmail.com>

Author: aroberts

directory-size.sh

@@ -11,4 +11,7 @@
 echo "# HELP node_directory_size_bytes Disk space used by some directories"
 echo "# TYPE node_directory_size_bytes gauge"
 du --block-size=1 --summarize "$@" \
-  | awk '{ print "node_directory_size_bytes{directory=\"" $2 "\"} "  $1 }'
+  | sed -E \
+    -e 's/\\/\\\\/g' \
+    -e 's/"/\\"/g' \
+    -e 's/^([0-9]+)[[:blank:]](.+)$/node_directory_size_bytes{directory="\2"} \1/'