The question is simple:
Which is the painless way to migrate from MariaDB to MySQL?
I was thinking about make a complete dump of the databases and import it on the new DB, but having the possibility of made it clean i dont know which could be the better option...
Any opinion?
I do not know of any other easier method; just use mysqldump and the commandline mysql to import the dump.
MariaDB is a fork of MySQL so all the normal tools work and also work between the too. In there is a problem when importing (like when you use the new "json" datatype and the other system does not support it) the import will tell you about it. In my experience this hardly ever occurs and when it does it is pretty clear what to do: directly alter the import or make the import again with different export parameters.