Single Layer Solution: Db Migrator

public async Task MigrateAsync()
{
    var initialMigrationAdded = AddInitialMigrationIfNotExist();

    if (initialMigrationAdded)
    {
        return;
    }

    Logger.LogInformation("Started database migrations...");

    await MigrateDatabaseSchemaAsync();
    await SeedDataAsync();

    Logger.LogInformation($"Successfully completed host database migrations.");

    var tenants = await _tenantRepository.GetListAsync(includeDetails: true);

    var migratedDatabaseSchemas = new HashSet<string>();
    foreach (var tenant in tenants)
    {
        using (_currentTenant.Change(tenant.Id))
        {
            if (tenant.ConnectionStrings.Any())
            {
                var tenantConnectionStrings = tenant.ConnectionStrings
                    .Select(x => x.Value)
                    .ToList();

                if (!migratedDatabaseSchemas.IsSupersetOf(tenantConnectionStrings))
                {
                    await MigrateDatabaseSchemaAsync(tenant);

                    migratedDatabaseSchemas.AddIfNotContains(tenantConnectionStrings);
                }
            }

            await SeedDataAsync(tenant);
        }

        Logger.LogInformation($"Successfully completed {tenant.Name} tenant database migrations.");
    }

    Logger.LogInformation("Successfully completed all database migrations.");
    Logger.LogInformation("You can safely end this process...");
}

public class BookstoreDbSchemaMigrator : ITransientDependency
{
    private readonly IServiceProvider _serviceProvider;

    public BookstoreDbSchemaMigrator(
        IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;
    }

    public async Task MigrateAsync()
    {
        
        /* We intentionally resolving the BookstoreDbContext
         * from IServiceProvider (instead of directly injecting it)
         * to properly get the connection string of the current tenant in the
         * current scope.
         */

        await _serviceProvider
            .GetRequiredService<BookstoreDbContext>()
            .Database
            .MigrateAsync();

    }
}