[whois_] Plugin to monitor domain registration expiries

Signed-off-by: Olivier Mehani <shtrom@ssji.net>

plugins/network/whois_

@@ -0,0 +1,64 @@
+#!/bin/sh
+
+set -eu
+
+# shellcheck disable=SC1090
+. "${MUNIN_LIBDIR}/plugins/plugin.sh"
+
+if [ "${MUNIN_DEBUG:-0}" = 1 ]; then
+	set -x
+fi
+
+EXTRACT_RE='s/^.*[Ee]xpir.*: //'
+CACHE_EXPIRY=60 # minutes
+
+config() {
+	NAME=${1}
+	FIELDNAME="$(clean_fieldname "${NAME}")"
+	cat << EOF
+graph_title "Domain registration expiry for ${NAME}"
+graph_category network
+graph_vlabel days
+${FIELDNAME}.label expiry
+${FIELDNAME}.cdef ${FIELDNAME},86400,/
+${FIELDNAME}.warning 7:
+${FIELDNAME}.critical 3:
+EOF
+}
+
+fetch() {
+	NAME=${1}
+	FIELDNAME="$(clean_fieldname "${NAME}")"
+
+	CACHEFILE="${MUNIN_PLUGSTATE}/$(basename "${0}").${FIELDNAME}.cache"
+
+	if [ -z "$(find "${CACHEFILE}" -mmin -${CACHE_EXPIRY} 2>/dev/null)" ]; then
+		EXPIRY="$(whois "${NAME} 2>/dev/null" | sed -n "${EXTRACT_RE}p")"
+		EXPIRY_TS="$(date +%s -d "${EXPIRY}")"
+
+		NOW_TS="$(date +%s)"
+		DELTA_TS=$((EXPIRY_TS-NOW_TS))
+
+		echo "${FIELDNAME}.value ${DELTA_TS}" > "${CACHEFILE}"
+	fi
+
+	cat "${CACHEFILE}"
+}
+
+main() {
+	NAME="$(echo "${0}" | sed 's/.*_//')"
+	MODE="${1:-}"
+
+	case "${MODE}" in
+		'config')
+			config "${NAME}"
+			;;
+		*)
+			fetch "${NAME}"
+			;;
+	esac
+}
+
+main "$@"
+
+# vim: ft=sh