Handle case where MariaDB database has no root password

Author: Paraphraser

.templates/mariadb/iotstack_healthcheck.sh

@@ -8,7 +8,13 @@ HEALTHCHECK_PORT="${MYSQL_TCP_PORT:-3306}"
 EXPECTED="mysqld is alive"
 
 # run the check
-RESPONSE=$(mysqladmin -p${MYSQL_ROOT_PASSWORD} ping -h localhost)
+if [ -z "$MYSQL_ROOT_PASSWORD" ] ; then
+   RESPONSE=$(mysqladmin ping -h localhost)
+else
+   # note - there is NO space between "-p" and the password. This is
+   # intentional. It is part of the mysql and mysqladmin API.
+   RESPONSE=$(mysqladmin -p${MYSQL_ROOT_PASSWORD} ping -h localhost)
+fi
 
 # did the mysqladmin command succeed?
 if [ $? -eq 0 ] ; then