I managed to connect to cloud sql via JDBCIO
DataSourceConfiguration.create("com.mysql.jdbc.Driver","jdbc:mysql://google/?cloudSqlInstance=::&socketFactory=com.google.cloud.sql.mysql.SocketFactory&user=&password=")
This works, however, the batch writes takes between 2-5 minutes for 1000 records, which is terrible. i have tried different networks to see if this was related, and the results were consistent.
Anyone have any ideas?