AwadyLab.HttpKit.AspNetCore 1.0.1

AwadyLab.HttpKit.AspNetCore

ASP.NET Core integration for AwadyLab.HttpKit: header propagation, the tenant, region and caller identity from HttpContext, and circuit-breaker health checks.

Key Highlights

• Header Propagation Without Smuggling: headers captured from the incoming request ride along on every HttpKit call, and pass the client's header policy like any other header — a propagated header that violates it is rejected, not smuggled through.
• Multi-Tenancy Without Plumbing: the tenant and region of the current request drive tenant-mapped base URLs, per-tenant authentication and tenant-isolated cache keys, without passing a tenant on every call.
• Per-User Cache Isolation: the caller's identity goes into cache keys, so a cached response is never served to a different user.
• Dependency Health: circuit-breaker state becomes health-check state, per client if you want it.

Installation

dotnet add package AwadyLab.HttpKit.AspNetCore

Quickstart

using AwadyLab.HttpKit.AspNetCore;

var httpKit = builder.Services.AddHttpKit(options => { /* clients, defaults, auth */ });

httpKit.AddAspNetCore(propagation =>
{
    propagation.Headers.Add("X-Correlation-Id");
    propagation.Headers.Add("X-Request-Id");
});
builder.Services.AddHealthChecks().AddHttpKitHealthChecks();

var app = builder.Build();
app.UseHeaderPropagation();     // captures the headers of each incoming request
app.MapHealthChecks("/health");

AddAspNetCore is shorthand for the four registrations below; call them one by one to pick only some.

1. Header Propagation

httpKit.AddHttpKitHeaderPropagation(propagation =>
{
    propagation.Headers.Add("X-Correlation-Id");
    propagation.Headers.Add("X-Tenant-Id", "X-Upstream-Tenant");   // inbound name → outbound name
});

app.UseHeaderPropagation();

Configuration is ASP.NET Core's own HeaderPropagationOptions, so renaming a header or computing a value works as documented there. The middleware captures the headers; HttpKit adds them to every HttpKit request:

• The caller wins: a header the request already carries is never overwritten; propagation only fills in what is missing.
• Policed: propagation runs before header sanitization, so a propagated value with a CR/LF, or a header the client forbids, is rejected like any other.
• Harmless outside a request: a background job or startup probe has nothing captured, and nothing is added.
• No middleware, no propagation: without app.UseHeaderPropagation() nothing is captured — not an error.

2. Tenant, Region & Identity

Tenant (AddHttpContextTenant)

using AwadyLab.HttpKit.AspNetCore.Routing;

httpKit.AddHttpContextTenant(tenant =>
{
    tenant.Sources.Clear();
    tenant.Sources.Add(TenantSource.Header);
    tenant.Sources.Add(TenantSource.HostPrefix);
    tenant.HeaderName = "X-Tenant";
});

Sources are tried in order; the first that yields a value wins. (This TenantSource lives in AwadyLab.HttpKit.AspNetCore.Routing; the core package's AwadyLab.HttpKit.Options.TenantSource is a different setting — whether a client takes the tenant from the call or from this accessor.)

The tenant feeds the core package's Tenants.BaseUrls, Tenants.AuthProviders, per-tenant token caching (PerTenant) and Caching.IncludeTenant. A per-call RequestOptions.Tenant still takes precedence under the default Tenants.Source = RequestThenAmbient.

Region (AddHttpContextRegion)

The region feeds Regions.BaseUrls and Regions.AuthProviders.

Identity (AddHttpContextAuthContext)

For an authenticated user, the subject is the first of the NameIdentifier, sub and Name claims. It is hashed into the cache key of every client with Caching.IncludeAuthContext (on by default), so a cached response is never served to a different caller. Register it whenever a client caches responses that depend on who asked.

3. Health Checks

builder.Services.AddHealthChecks()
    .AddHttpKitHealthChecks();                                        // one check over every client

builder.Services.AddHealthChecks()
    .AddHttpKitClientHealthChecks(["HttpKit:MyApp.GitHubClient", "HttpKit:MyApp.StripeClient"]);  // one per client

The data payload names each client, its state, when it opened and the failure that tripped it. One check per client shows which dependency is failing instead of one aggregate red light. Both methods also take a failureStatus, tags and, for the single check, a name. HttpKitHealthCheckOptions.ClientNames limits the single check to some clients.

Client names follow HttpKit:{FullTypeName} (HttpKit:{FullTypeName}#stream for a streamed client).

License

Proprietary — see the core package, AwadyLab.HttpKit. Full documentation lives in the core package's repository (README.md).