Have you tried to publish first your data/connection to your server and then connect the TWB files to
your published data in the Tableau server?
1. Publish the connection/data first to your Tableau Server.
2. Connect into the data using Tableau Desktop via "On a server" connection- select Tableau Server and login.
You'll see there your published data sources.
3. Create your dashboards. and then save it as .twb file.
4. Publish the .twb file to the server.
5. Make a tabcmd batch file which will be handling the refresh and publishing of the data and the dashboards.
Yes, this does solve the issue with tabcmd. But like I have said, that means I still have to open each workbook in Desktop and replace the connections with the published data sources on the server for each site. The whole purpose of the "automation" is to do bulk updating and publishing without having to open one by one in Tableau Desktop.
You can do the updating and publishing of Dashboards in bulk using tabcmd without opening them one by one.
So the issue here will be the connection right? you want to connect the dashboards to your data in your local machine?
I have a project almost the same issue as yours. The only thing I did is to publish the extracts,connect the dashboards to the data in the server, overwrite it everyday, and refresh the dashboards using tabcmd.
The limitation is:
Calculations became part of published data source, no longer part of workbook.
So unless the extract is refreshed via Tableau, the calculation would be gone (say using Alteryx to generate .tde files, these files all working well for Tableau, until you decide to publish it and save the workbook, then use tabcmd to overwrite the published tde file using Alteryx generated .ted.)