How can I read request header from program.cs file in .netcore6 webapi - asp.net-core-webapi

Question

I have tenant id in request header. I want to connect database string based on the tenant id , how can i achieve this? I am using .netcore6 webapi. Thanks in advance.

Answer 1

You can achieve this requirement through Middleware. Here is the test result and sample.
My Test files and picutres
Test Method in HomeController
public IActionResult GetConnectionStringByTenantID()
{
bool testResult = false;
string msg = string.Empty;
try
{
testResult = _dbcontext.Database.CanConnect();
if (testResult)
{
msg = "connect sucessfully";
}
else
{
msg = "connect failed";
}
}
catch (Exception e)
{
msg = e.ToString();
throw;
}
return Ok(msg);
}
TenantMiddleware.cs
using WebApplication7.Models;
namespace WebApplication7
{
public class TenantMiddleware
{
private readonly RequestDelegate _next;
public TenantMiddleware(RequestDelegate next)
{
_next = next;
}
public async Task InvokeAsync(HttpContext context)
{
// Read the tenant ID from the request header
var tenantId = context.Request.Headers["Tenant-Id"].FirstOrDefault();
// Get the connection string for the tenant
var connectionString = GetConnectionStringForTenant(tenantId);
// Create a Tenant object with the tenant ID and connection string
var tenant = new Tenant
{
Id = tenantId,
ConnectionString = connectionString
};
// Set the Tenant object in the context
context.Items["Tenant"] = tenant;
// Call the next middleware component in the pipeline
await _next(context);
}
private string GetConnectionStringForTenant(string tenantId)
{
// Implement logic to get the connection string for the tenant
// This can be from a configuration file or a database
// For example, you can have a dictionary of tenant IDs and connection strings
var connectionStrings = new Dictionary<string, string>
{
{ "tenant1", "Data Source=...My real test connectionstring..." },
{ "tenant2", "Server=server2;Database=database2;User Id=user2;Password=password2;" }
};
if (tenantId == null || tenantId.Equals(string.Empty))
{
tenantId = "tenant1";
}
// Return the connection string for the tenant ID
if (connectionStrings.TryGetValue(tenantId, out var connectionString))
{
return connectionString;
}
// If the tenant ID is not found, throw an exception
throw new ArgumentException($"Invalid tenant ID: {tenantId}");
}
}
}
MyDbContext.cs
using Microsoft.EntityFrameworkCore;
using WebApplication7.Models;
namespace WebApplication7
{
public class MyDbContext : DbContext
{
private readonly Tenant _tenant = null!;
public MyDbContext()
{
}
public MyDbContext(DbContextOptions<MyDbContext> options, IHttpContextAccessor httpContextAccessor)
: base(options)
{
_tenant = httpContextAccessor.HttpContext.Items["Tenant"] as Tenant;
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer(_tenant.ConnectionString);
}
}
}
Program.cs
using Microsoft.EntityFrameworkCore;
namespace WebApplication7
{
public class Program
{
public static void Main(string[] args)
{
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddHttpContextAccessor();
builder.Services.AddDbContext<MyDbContext>();
// Add services to the container.
builder.Services.AddControllersWithViews();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
app.UseExceptionHandler("/Home/Error");
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseMiddleware<TenantMiddleware>();
app.UseRouting();
app.UseAuthorization();
app.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
app.Run();
}
}
}
Tenant.cs
namespace WebApplication7.Models
{
public class Tenant
{
public string? Id { get; set; }
public string? ConnectionString { get; set; }
}
}