Comment 0 for bug 1394137

Currently we use UNIX sockets based checks for "wait-for-haproxy-mysql-backend". That could cause deployment failure in a random manner then mysql service is not ready yet to accept TCP connections (there is no message "[Note] /usr/sbin/mysqld: ready for connections" in logs)

In order to fix it, we should use TCP connect based (management_vip:port) checks for wait-for-haproxy-mysql-backend.
Note, that the complete fix will be to move all exec checkers to puppet providers as a decorators, but for now we should first fix this execs as well.