node_exporter: Add verbose option

roles/node_exporter/files/node-exporter-run-textfile-collector.sh

@@ -6,19 +6,35 @@ umask 022
 
 PATH="/bin:/usr/bin:/usr/local/bin:/sbin:/usr/sbin:/usr/local/sbin"
 
+if [ "${1:-}" = "-v" ]; then
+    shift
+    VERBOSE=true
+else
+    VERBOSE=false
+fi
+
+if [ -n "${1:-}" ]; then
+    echo "Usage: $(basename "$0") [-v]" 1>&2
+    exit 1
+fi
+
 if [ "$(uname -s)" = "OpenBSD" ]; then
     OUTDIR="/var/db/node-exporter"
 else
     OUTDIR="/var/lib/prometheus/node-exporter"
 fi
+"$VERBOSE" && echo "Using output directory '${OUTDIR}'"
 
 for script in /usr/local/libexec/node-exporter/*; do
     [ -x "$script" ] || continue
+    "$VERBOSE" && echo "Processing script '${script}'"
     target="${OUTDIR}/$(basename "$script")"
     tmpfile="$(mktemp -p "$OUTDIR")"
     if "$script" > "$tmpfile" ; then
+        "$VERBOSE" && echo "  Success, updating stats"
         mv "$tmpfile" "$target"
     else
+        "$VERBOSE" && echo "  Failure, skipping stats update"
         rm -f "$tmpfile"
     fi
 done