EF Core Cosmos DB Identity Provider

This is a Cosmos DB implementation of an Identity provider for .NET Core 5, using the official EF Core Azure Cosmos DB Provider.

You can use this package to easily bootstrap an ASP.NET Identity Server backed by a CosmosDb database and EF Core, in place of SQL Server.

Installation (NuGet)

PM> Install-Package PieroDeTomi.EntityFrameworkCore.Identity.Cosmos

Integration Steps

Project Requirements

The following steps assume that you have an ASP.NET Core 5 Web Application project that uses Identity and/or IdentityServer features.

Cosmos DB Requirements

Database

Just as with EF Core on SQL Server, you have to manually create a database in your Cosmos DB instance to be able to operate.

Containers

Since migrations are NOT supported when using EF Core on Cosmos DB, you’ll have to manually create the following containers in your database:

Container Name	Partition Key
Identity	/Id
Identity_DeviceFlowCodes	/SessionId
Identity_Logins	/ProviderKey
Identity_PersistedGrant	/Key
Identity_Tokens	/UserId
Identity_UserRoles	/UserId
Identity_Roles	/Id

DbContext

You have to create a DbContext that implements the provided CosmosIdentityDbContext type.

To start off you can create just an empty DbContext class that satisfies the above requirement:

public class MyDbContext : CosmosIdentityDbContext<IdentityUser>
{
  public MyDbContext(DbContextOptions dbContextOptions, IOptions<OperationalStoreOptions> options)
    : base(dbContextOptions, options) { }
}

Later in your development you'll likely add some entities to your application: you'll update the DbContext class adding the DbSet<T> properties and overriding the OnModelCreating() method for entity mappings:

public class MyDbContext : CosmosIdentityDbContext<IdentityUser>
{
  public DbSet<SampleEntity> SampleEntities { get; set; }

  public DbSet<OtherSampleEntity> OtherSampleEntities { get; set; }

  public MyDbContext(DbContextOptions dbContextOptions, IOptions<OperationalStoreOptions> options)
    : base(dbContextOptions, options) { }

  protected override void OnModelCreating(ModelBuilder builder)
  {
    // DO NOT REMOVE THIS LINE. If you do, your context won't work as expected.
    base.OnModelCreating(builder);
    
    // TODO: Add your own fluent mappings
  }
}

As specified in the above code snippet, when overriding the OnModelCreating() method it is crucial to not remove the base.OnModelCreating(builder) call: if you do so, the identity configuration mappings won't be applied and the application won't work properly.

Configurations in Startup.cs File

Remove the Default Identity Provider

Remove the line where the default/current identity provider is added/configured.

If you just created a new project, this line should be something like:

services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
  .AddEntityFrameworkStores<ApplicationDbContext>();

Remove Default DbContext Configuration

Remove the line where the SQL DbContext is configured.

It should be something like:

services.AddDbContext<ApplicationDbContext>(options =>
  options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

Add Cosmos DB Identity Provider

Now add the Cosmos DB provider:

services.AddCosmosIdentity<MyDbContext, IdentityUser, IdentityRole>(
  // Auth provider standard configuration (e.g.: account confirmation, password requirements, etc.)
  options => ...,
  options => options.UseCosmos(
      "your_cosmos_db_URL",
      "your_cosmos_db_key",
      databaseName: "your_db"
  ),

  // If true, AddDefaultTokenProviders() method will be called on the IdentityBuilder instance
  addDefaultTokenProviders: false   
);

Update IdentityServer Configuration (If Applicable)

If your project is using IdentityServer, update the related configuration in order to use your new DbContext implementation:

// Note that we're using MyDbContext as the second type parameter here...
services.AddIdentityServer().AddApiAuthorization<IdentityUser, MyDbContext>();

This Provider & Identity UI

This provider is also compatible with Identity UI.

You can either use the default Identity UI (e.g.: in Startup.cs there's a call to AddDefaultUI() method) or use the scaffolded version of Identity UI. Both scenarios should work out of the box without having to do anything else.

Finally you can also use your own implementation of Identity UI, as long as you use the Identity services (e.g.: UserManager and SignInManager).

Available Services

This library registers in the service collection a basic Cosmos DB repository implementation, that you can resolve in your constructors requiring the IRepository interface.

An example:

public class MyClass {
  private readonly IRepository _repo;

  public MyClass(IRepository repo) {
    _repo = repo;
  }

  // ... Use the _repo instance methods to query the database
}

Available IRepository methods

Just for your information, here is a summary of the available methods in the IRepository interface:

Table<TEntity>()
GetById<TEntity>(string id)
TryFindOne<TEntity>(Expression<Func<TEntity, bool>> predicate)
Find<TEntity>(Expression<Func<TEntity, bool>> predicate)
Add<TEntity>(TEntity entity)
Update<TEntity>(TEntity entity)
DeleteById<TEntity>(string id)
Delete<TEntity>(TEntity entity)
Delete<TEntity>(Expression<Func<TEntity, bool>> predicate)
SaveChangesAsync()

Changelog

v1.0.6

Introduced support for IUserLoginStore<TUser> in User Store

v1.0.5

Introduced support for IUserPhoneNumberStore<TUser> in User Store

v1.0.4

Introduced support for IUserEmailStore<TUser> in User Store

hendriksteinhorst/efcore-identity-cosmos