EF Core and ASP.NET Core Identity Seed Data

DbInitializer.cs

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using System.Linq;

namespace My.App.Data
{
    public class DbInitializer : IDbInitializer
    {
        private readonly ApplicationDbContext _context;
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly RoleManager<IdentityRole> _roleManager;

        public DbInitializer(
            ApplicationDbContext context,
            UserManager<ApplicationUser> userManager,
            RoleManager<IdentityRole> roleManager)
        {
            _context = context;
            _userManager = userManager;
            _roleManager = roleManager;
        }

        //This example just creates an Administrator role and one Admin users
        public async void Initialize()
        {
            //create database schema if none exists
            _context.Database.EnsureCreated();

            //If there is already an Administrator role, abort
            if (_context.Roles.Any(r => r.Name == "Administrator")) return;

            //Create the Administartor Role
            await _roleManager.CreateAsync(new IdentityRole("Administrator"));

            //Create the default Admin account and apply the Administrator role
            string user = "[email protected]";
            string password = "z0mgchangethis";
            await _userManager.CreateAsync(new ApplicationUser { UserName = user, Email = user, EmailConfirmed = true}, password);
            await _userManager.AddToRoleAsync(await _userManager.FindByNameAsync(user), "Administrator");
        }
    }
}

IDbInitializer.cs

namespace My.App.Data
{
    public interface IDbInitializer
    {
        void Initialize();
    }
}

Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using My.App.Data;

namespace My.App.Admin
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);

            if (env.IsDevelopment())
            {
                // For more details on using the user secret store see http://go.microsoft.com/fwlink/?LinkID=532709
                builder.AddUserSecrets<Startup>();
            }

            builder.AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddDbContext<ApplicationDbContext>(options =>
                options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

            services.AddIdentity<ApplicationUser, IdentityRole>()
                .AddEntityFrameworkStores<ApplicationDbContext>()
                .AddDefaultTokenProviders();

            services.AddMvc();

            // Add Database Initializer
            services.AddScoped<IDbInitializer, DbInitializer>();

            // Add application services.
            services.AddTransient<IEmailSender, AuthMessageSender>();
            services.AddTransient<ISmsSender, AuthMessageSender>();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IDbInitializer dbInitializer)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseDatabaseErrorPage();

                // Browser Link is not compatible with Kestrel 1.1.0
                // For details on enabling Browser Link, see https://go.microsoft.com/fwlink/?linkid=840936
                // app.UseBrowserLink();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
            }

            app.UseStaticFiles();

            app.UseIdentity();

            //Generate EF Core Seed Data
            dbInitializer.Initialize();

            // Add external authentication middleware below. To configure them please see http://go.microsoft.com/fwlink/?LinkID=532715

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}