How to get .NET Core 3.1 login to persist across multiple EC2 instances in Elastic Beanstalk - amazon-ec2

Question

I have a small .NET Core 3.1 app that needs to scale occasionally. I need the logged in users information to persist across any instance that EB spins up. I'd like to do this using the SQL Server RDS we have set up. I've attempted to add the Distributed Sql Server Cache and have set up the table for storing the sessionstate, as described in the documentation... but the login info is not being persisted to this table.
In my Startup.cs ConfigureServices I have:
var sqlSessionConnString = new SqlConnectionStringBuilder(Configuration.GetConnectionString("SqlSession"));
services.AddDistributedSqlServerCache(options =>
{
options.ConnectionString = sqlSessionConnString.ConnectionString;
options.SchemaName = "dbo";
options.TableName = "TableName";
});
services.AddSession();
When I then log in and check the table there is no data in the table, but my login still works.
What do I have to do to tell Identity to persist the login info in the database instead of in server memory so that my users' login is persisted no matter which instance they are being routed to?

Answer 1

Answering your question: to configure session you also need to add middleware app.UseSession() usage inside your Configure method so
public void ConfigureServices(IServiceCollection services)
{
services.AddDistributedSqlServerCache(options =>
{
options.ConnectionString =
#"Server=localhost\SQLEXPRESS;Database=master;Trusted_Connection=True;";
options.SchemaName = "dbo";
options.TableName = "TestCache";
});
services.AddSession();
//to inject httpcontet into controller
services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services.AddControllers();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseSession();
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
//your auth settings
//...
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
And now inside your Controller you can save additional values into cache by calling
_distributedCache.SetString("TestString", "TestValue");
or store data to only specific use session by
_context.Session.SetString("name", "John");
And here is a concrete example
[ApiController]
[Route("[controller]")]
public class WeatherForecastController : ControllerBase
{
private readonly IDistributedCache _distributedCache;
private HttpContext _context;
public WeatherForecastController(ILogger<WeatherForecastController> logger,
IDistributedCache distributedCache,
IHttpContextAccessor httpContextAccessor)
{
_distributedCache = distributedCache;
_context = httpContextAccessor.HttpContext;
}
public string Get()
{
_distributedCache.SetString("TestString", "TestValue");
if (_context.Session.Keys.Contains("name"))
return $"Hello {_context.Session.GetString("name")}";
_context.Session.SetString("name", "John");
return "Session was created";
}
}
You will see that inside SQL table data will be inserted
and session cookies were created (.AspNetCore.Session)