How to automate the transfer of data from one database to another?

Question

MySQL

The situation is this: there are two software and hardware systems with their own MySQL databases. The second system requires data from the database of the first system. The database is constantly updated first. For now, we manage by manually exporting data from the first database to the second. The problem is that due to the technical nuances of local networks and firewalls, it is impossible to reach the first from the second system, while from the first it is possible to contact the second.
How can we automate the transfer of data from the first database to the second?

Answer 1

Take any VPN organization protocol or even a trite ssh tunnel - and there will be two-way communication.
If the second DBMS data from the first is only needed for reading, then configure the replica.