Seed roles in an ASP.NET MVC Core project with Entity Framework

Question

I am trying to seed some roles to my identity db context, when I initially create the database.

For that I tried to implement the code like it was stated here: https://stackoverflow.com/a/29547994/985798

I tried this in the ConfigureServices-method inside my Startup-class: public void ConfigureServices(IServiceCollection services)

using this snippet:

var rolestore =
    new Microsoft.AspNetCore.Identity.EntityFrameworkCore.
        RoleStore<Microsoft.AspNetCore.Identity.EntityFrameworkCore.IdentityRole>(identityContext);

var roleManager = new Microsoft.AspNetCore.Identity.RoleManager
                  <Microsoft.AspNetCore.Identity.EntityFrameworkCore.IdentityRole>(rolestore);

//use rolemanager to insert roles etc.

The problem is, that it seems to not work in an fresh Core-project, created with Visual Studio 2017.

It gives me the following build error:

CS7036 There is no argument given that corresponds to the required formal parameter 'roleValidators' of 'RoleManager.RoleManager(IRoleStore, IEnumerable>, ILookupNormalizer, IdentityErrorDescriber, ILogger>, IHttpContextAccessor)'

Even if I use the other overload (with null values for the other parameters), the RoleManager seems to have no "Create" method anymore.

So, I am stuck at this point. What do I need to do? Has something changed in the ASP.NET MVC Core implementation of the rolemanager? Do I use something wrong?

After you get it compiled, it may prove a problem to get the Seed() executed. Afaik that's planned for EfCore 2.0 . — H H, Apr 23 '17 at 16:42
What do you mean exactly? Running it inside the startup should work just fine, shouldn't it? I know, it might not be the best place, but I assume it should work. — Jannik, Apr 23 '17 at 17:22
Instead of "newing" RoleManager try resolving it in `Configure` method. [Similar post](https://stackoverflow.com/questions/39934201/asp-net-core-identity-add-custom-user-roles-on-application-startup/39934793#39934793) and [MusicStore](https://github.com/aspnet/MusicStore/blob/1.0.0/src/MusicStore/Models/SampleData.cs#L22-L34) — tmg, Apr 24 '17 at 07:21
Works for me. Like you said, you can use the IServiceCollection to retreave both your UserManager and your RoleManager. — Jannik, Apr 25 '17 at 04:26

mvermef · Accepted Answer · 2017-04-25T17:09:42.163

4

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;

public static class Seed
{
    public static void Initialize(IServiceProvider provider)
    {
        var _context = provider.GetRequiredService<ApplicationDbContext>();
        var userManager = provider.GetRequiredService<UserManager<ApplicationUser>>();
        var roleManager = provider.GetRequiredService<RoleManager<IdentityRole>>();


    }
}

Then below the majority of the code in the in the Configure() in startup.cs

Seed.Initialize(app.ApplicationServices);

HTH (hope that helps).

edited Apr 25 '17 at 17:09

answered Apr 25 '17 at 05:45

mvermef

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Thanks, but what does HTH mean? – Jannik Apr 25 '17 at 06:13
HTH (hope that helps) – mvermef Apr 25 '17 at 17:09
3

How do you handle the await on the async calls in a non async method? – Tim Meers Jun 18 '17 at 15:37
If you added in Configure, doesn't will executed every time that a request is made? – William Ardila Dec 26 '17 at 21:46
yes but you could also check for whether or not migrations need to run which would minimize the instantiated code. – mvermef Dec 26 '17 at 23:46
When I try and run this i get the error: Cannot resolve scoped service 'ProjectName.Data.ApplicationDbContext' from root provider.' Any thoughts? – dave317 Mar 01 '18 at 07:26
@zszep I honestly don't remember, I was able to find a way to seed roles in my project(s) though. If you need assistance let me know and I'll try and help. Maybe open up a new question on how to seed roles/users. – dave317 Nov 18 '19 at 21:22

Seed roles in an ASP.NET MVC Core project with Entity Framework

1 Answers1