We have a web system that uses MySQL spatial databases. We want to migrate from MySQL to PostgreSQL. I've been looking for methods to do it. I have found some tools that help you to migrate. However most of them do not support spatial data like https://github.com/philipsoutham/py-mysql2pgsql.
I also took a look over How to migrate spatial tables from MSSQL to PostGIS. I have just seen this post. I haven't tried it yet, I don't know if it could work for MySQL.