SPMigration tool from MS to migrate to SPO from SP 2010 on-prem

As per my requirements, I wanted to migrate the contents, images, lists, doc.library etc from my SP 2010 to customer's SPO environment. Customer doesnt want to use any third party tools / purchase.

So it has to be done either through manually or using free tools. <p>

 During Microsoft Ignite's Conf 2017, Jeff Teper has announced  that, SP migration tool will be available this year for migration from legacy SP to SPO <O365>.  <p>

If they have released SPMigration tool, can anyone please share the link/source ?

and if yes, how many previous  versions are supported by this tool. 

Can we migrate from SP 2010 on-premises to SPO (O365) ? if yes, what are the permissions we require at each end?

 i am little bit doubtful about the permissions, one  env is in SP 2010 -on-prem and other is in cloud. how the authentication/authorization and migration works between these two disparate environments.