Unfortunately, I don't think there is an easy way to deal with your issue.
I think that the easiest solution would be to install Tableau Server with the local Authentication mode and deploy a job that will create all the users from your AD in Tableau repository (including their password). That way, you will be able to add yours customers account.
The alternative would be to create an account for your customers in your AD.
There might also be other way using a webpage for sharing specific workbooks that would connect to Tableau Server using a trusted account. I have never done it so I'm not sure to know how.
So currently the known methods of using mixed method authentication are either to do a full uninstall and reinstall of Tableau Server (generally not preferred) or when using Active Directory Authentication, perform the following steps:
1. Create a CSV file.
2. Enter all user information that is desired to be in Tableau Server for the users that do not have accounts or cannot have accounts created in Active Directory.
3. In Tableau Server navigate to the 'Users' tab and select the 'Import From File' option which will prompt for the location of the CSV file created using steps 1 and 2.
The CSV file would then just need to be updated as needed (new user info, user's credentials need to change, etc.)
Currently, multiple users have voiced their opinion for this functionality to be made possible in future releases.
You can't mix authentication mode.
Select whether to use Active Directory to authenticate users on the server. Select Use Local Authentication to create users and assign passwords using Tableau Server's built-in user management system. You cannot switch between Active Directory and Local Authentication later.
I haven't heard of Bassel's workaround...if you try it, can you let us know if it works?
what you propose is a very interesting concept, but does it actually work? we have configured AD integration and if we want to add local non-AD users via any method, then it errors out.
My sincerest apologies, it would appear I misinterpreted something I previously read. I thought it was possible to import users not in AD to an AD auth configured environment using the import from file option but apparently that option is only if the users are located in Active Directory.