[puppet4] database task fails to detect mysqld backend start

During deployment of environment using Puppet 4, primary-database task fails with the next error:

(/Stage[main]/Osnailyfacter::Database::Database_backend_wait/Osnailyfacter::Wait_for_backend[mysql]/Haproxy_backend_status[mysql]/ensure) change from down to up failed: Timeout waiting for HAProxy backend: 'mysqld' status to become: 'up' after 600 seconds!

On primary controller mysqld is launched and responsive, moreover galera status is synced:

mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 12472
Server version: 5.6.34-0~u16.04+mos1 (Ubuntu), wsrep_25.18

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SHOW STATUS LIKE 'wsrep_local_state';
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| wsrep_local_state | 4 |
+-------------------+-------+
1 row in set (0.01 sec)

But when running galeracheck script, we get:

/usr/bin/galeracheck
HTTP/1.1 503 Service Unavailable
Content-Type: text/plain
Connection: close
Content-Length: 44

Percona XtraDB Cluster Node is not synced.

When checking /etc/wsrepclustercheckrc I found that mysql credentials are empty:

MYSQL_USERNAME=""
MYSQL_PASSWORD=""
MYSQL_HOST="192.168.0.3"
MYSQL_PORT="3307"
AVAILABLE_WHEN_DONOR=${3:-1}
ERR_FILE="${4:-/dev/null}"
AVAILABLE_WHEN_READONLY=${5:-1}
DEFAULTS_EXTRA_FILE=${6:-/etc/my.cnf}