Migrations CLI Fails if default ASP.NET Configuration is used

[SergeyBarskiy]

Try to add a migration when default configuraiton provider is used using CLI
dotnet ef migrations add Initial
Exception will be thrown: Value cannot be null.

Steps to reproduce

Create ASP.NET Core project that is using default configuration:

public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;

Try to run ef migrations add. This will throw the exception because it cannot find connection string.
Workaround:

public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
            //support migrations with default configuration
            if (string.IsNullOrEmpty(Configuration["ConnectionStrings:DefaultConnection"]))
            {
                Configuration["ConnectionStrings:DefaultConnection"] = "Server=.;Database=ContactsDatabase;Trusted_Connection=True;MultipleActiveResultSets=true";
            }
        }

Another workaround - mark appsettings.json to copy to output folder always.

Further technical details

EF Core version: 2.0 preview 2
Database Provider: Microsoft.EntityFrameworkCore.SqlServer
Operating system: Windows 10
IDE: Visual Studio 2017

[bricelam]

Another workaround - mark appsettings.json to copy to output folder always.

This shouldn't be necessary since the current directory was switched to the project directory in version 2.0.0-preview1-final. (See #7588)

Could you share your Program class code?

[SergeyBarskiy]

Sure
public class Program
{
public static void Main(string[] args)
{
BuildWebHost(args).Run();
}

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .Build();
}

[SergeyBarskiy]

My bad. I was still using version 1.0.1 of tools. Did not realize it got renamed not to have .Net suffix.