0(19625) ERROR: db_mysql [km_my_con.c:139]: db_mysql_new_connection(): driver error: Can't connect to MySQL server on 'kamailio' (4)
 0(19625) ERROR: <core> [db.c:319]: db_do_init2(): could not add connection to the pool
 0(19625) ERROR: dialplan [dp_db.c:179]: dp_connect_db(): unable to connect to the database
 0(19625) ERROR: dialplan [dialplan.c:191]: mod_init(): could not initialize data
 0(19625) ERROR: <core> [core/sr_module.c:850]: init_mod(): Error while initializing module dialplan (/usr/lib64/kamailio/modules/dialplan.so)
ERROR: error while initializing modules


from my kamailio.cfg i defined the DBURL like this:

# Use /etc/my.cnf.d/kamailio.cnf to store credentials
# within a mysql-db-group
#!define DBURL "mysql://[kamailio]/kamailio"

and special modules can use it like this (or via DBURL)
modparam("sqlops", "sqlcon", "cb=>mysql://[kamailio]/kamailio")

cat /etc/my.cnf.d/kamailio.cnf

# MySQL configuration group for kamailio
[kamailio]
user=kamailio
password="kamailiorw"
host=172.20.100.22


rpm -qa | grep kam
kamailio-dialplan-5.3.0-13.1.x86_64
kamailio-websocket-5.3.0-13.1.x86_64
kamailio-jansson-5.3.0-13.1.x86_64
kamailio-mysql-5.3.0-13.1.x86_64
kamailio-tls-5.3.0-13.1.x86_64
kamailio-ims-5.3.0-13.1.x86_64
kamailio-statsd-5.3.0-13.1.x86_64
kamailio-5.3.0-13.1.x86_64
kamailio-redis-5.3.0-13.1.x86_64
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