From 09974133b3d4c47c3c1f4c18264ec9500835c12d Mon Sep 17 00:00:00 2001
From: Adam Mizerski <adam@mizerski.pl>
Date: Mon, 12 Jul 2021 09:54:09 +0200
Subject: [PATCH] ssl-certificate-expiry: fix handling domains starting with
 digits

resolves #1224
---
 plugins/ssl/ssl-certificate-expiry | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/plugins/ssl/ssl-certificate-expiry b/plugins/ssl/ssl-certificate-expiry
index 8a1d1b31..6c6b6d6e 100755
--- a/plugins/ssl/ssl-certificate-expiry
+++ b/plugins/ssl/ssl-certificate-expiry
@@ -165,6 +165,11 @@ print_expire_days() {
     fi
 }
 
+my_clean_fieldname() {
+    # if a domain starts with a digit, or its an IP address, prepend '_'
+    clean_fieldname "$(echo "$@" | sed -E 's/^([0-9])/_\1/')"
+}
+
 main() {
     for service in $services; do
 	if echo "$service" | grep -q "_"; then
@@ -176,7 +181,7 @@ main() {
 	    port=443
 	    starttls=""
 	fi
-	fieldname="$(clean_fieldname "$service")"
+	fieldname="$(my_clean_fieldname "$service")"
 	valid_days=$(print_expire_days "$host" "$port" "$starttls")
 	extinfo=""
 	[ -z "$valid_days" ] && valid_days="U"
@@ -197,7 +202,7 @@ case ${1:-} in
 	echo 'graph_category security'
 	echo "graph_info This graph shows the numbers of days before certificate expiry"
 	for service in $services; do
-	    fieldname=$(clean_fieldname "$service")
+	    fieldname=$(my_clean_fieldname "$service")
 	    echo "${fieldname}.label $(echo "${service}" | sed 's/_/:/')"
 	    print_thresholds "${fieldname}" warning critical
 	done