This post is just a collection of a couple of links around using Google Authentication and .NET Core Identity. 

• Free Code Camp: Step by Step adding Google Auth to .NET Core project.
  • By default the SQL Database to support this will be located on your C:\Users\[username] folder.  Change the connection string in appsettings.json to create the database in SQL Server.
• Microsoft Documentation: Good overview / walk through about using Google Auth but not enough to get the site to work (need the link above).
• Google Developer Console: This where you need to get your Auth Key.

I have used the Data Repo pattern in .NET Core but wanted to generate the models similar to .NET. 

• This stackover flow post is a good reference. 
• How to scaffold models
• Scaffold-DbContext "Server=yourserver;Database=yourdatabase;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models
• With table params 
• Scaffold-DbContext "Server=(localdb)\mssqllocaldb;Database=DatabaseName;Trusted_Connection=True;"
  -Provider Microsoft.EntityFrameworkCore.SqlServer
  -OutputDir Models -Context NorthwndContext
  -Tables Products,Categories,Suppliers -Force