nagios/check_gitea_version: proper nagios' way to separate address and hostname

nagios/check_gitea_version.sh

@@ -6,14 +6,43 @@
 # Stop at first uncatched error
 set -e
 
-# note: some local problems with IPv4, the quickest way was to force IPv6.
-LOCAL_VERSION="$( wget -6 -O - -q "https://$( hostname -f )/api/v1/version" | sed -n 's/{"version":"\([^"]\+\)"}/\1/p' )"
+usage() {
+	cat <<EOF
+$0 -H hostname -I address
+
+TODO: write the rest :)
+EOF
+}
+
+while getopts H:I: f; do
+	case "$f" in
+		'H')
+			HOSTNAME="$OPTARG"
+			;;
+
+		'I')
+			HOSTADDRESS="$OPTARG"
+			# If there is some ":" in the adress, we treat it as IPv6
+			if echo "$HOSTADDRESS" | grep ":" >/dev/null 2>&1; then
+				HOSTADDRESS="[$HOSTADDRESS]"
+			fi
+			;;
+
+		\?)
+			usage
+			exit 1
+			;;
+	esac
+done
+
+
+INSTALLED_VERSION="$( wget -O - --header="Host: $HOSTNAME" --no-check-certificate -q "https://$HOSTADDRESS/api/v1/version" | sed -n 's/{"version":"\([^"]\+\)"}/\1/p' )"
 UPSTREAM_VERSION="$( wget -q -O - "https://dl.gitea.io/gitea/" | egrep -- '<a href="/gitea/[0-9]+\.[0-9]+\.[0-9]+/?"' | egrep -o "[0-9]+\.[0-9]+\.[0-9]+" | sort --version-sort | tail -n 1 )"
 
-if [ "$UPSTREAM_VERSION" = "$LOCAL_VERSION" ]; then
-	echo "OK ($LOCAL_VERSION / $UPSTREAM_VERSION)"
+if [ "$UPSTREAM_VERSION" = "$INSTALLED_VERSION" ]; then
+	echo "OK ($INSTALLED_VERSION / $UPSTREAM_VERSION)"
 	exit 0
 else
-	echo "WARNING ($LOCAL_VERSION / $UPSTREAM_VERSION)"
+	echo "WARNING ($INSTALLED_VERSION / $UPSTREAM_VERSION)"
 	exit 1
 fi