Overview

In Silky, a Host is the process container that starts the application, initializes modules, and provides external communication capabilities. Silky offers several host types based on different deployment scenarios.

Host Types

GeneralHost — RPC-Only Service

A pure RPC microservice that does not expose external HTTP endpoints. Used for backend business services called only by other services via RPC.

// Program.cs
await Host.CreateDefaultBuilder(args)
    .ConfigureSilkyGeneralHostDefaults<OrderHostModule>()
    .Build()
    .RunAsync();

Module reference:

<PackageReference Include="Silky.Agent.Host" Version="3.9.2" />

Characteristics:

• Exposes only the DotNetty TCP RPC port
• No HTTP middleware pipeline
• Lower resource footprint
• Ideal for CPU-intensive, pure backend services

WebHost — RPC + HTTP Service

A service that exposes both RPC (for service-to-service calls) and an HTTP server (for internal/partial external access, Swagger, health checks, etc.).

// Program.cs
await Host.CreateDefaultBuilder(args)
    .ConfigureSilkyWebHostDefaults<OrderHostModule>(webBuilder =>
    {
        webBuilder.UseStartup<Startup>();
    })
    .Build()
    .RunAsync();

Or with WebApplication (minimal hosting):

var builder = WebApplication.CreateBuilder(args);
builder.Host.ConfigureSilkyGeneralHostDefaults<OrderHostModule>();
builder.Services.AddSilkyHttpCore().AddSwaggerDocuments();

var app = builder.Build();
app.MapSilkyRpcServices();
app.UseSwagger();
app.Run();

WebSocketHost — RPC + WebSocket

A service that supports WebSocket connections in addition to RPC. Use for real-time bidirectional communication (e.g., notifications, chat).

await Host.CreateDefaultBuilder(args)
    .ConfigureSilkyWebSocketHostDefaults<NotificationHostModule>(webBuilder =>
    {
        webBuilder.UseStartup<Startup>();
    })
    .Build()
    .RunAsync();

Module reference:

<PackageReference Include="Silky.WebSocket" Version="3.9.2" />

GatewayHost — HTTP API Gateway

The external-facing HTTP gateway. Receives REST requests from clients and routes them to internal microservices via RPC.

await Host.CreateDefaultBuilder(args)
    .ConfigureSilkyGatewayDefaults<GatewayModule>(webBuilder =>
    {
        webBuilder.UseStartup<Startup>();
    })
    .Build()
    .RunAsync();

Characteristics:

• Only exposes HTTP (no business RPC port)
• Aggregates Swagger docs from all services
• Handles JWT authentication, CORS, rate limiting
• Enables real-time service route updates via registry subscription

Port Configuration

Configure listening ports per host in appsettings.json:

{
  "rpc": {
    "port": 2200,
    "host": "0.0.0.0"
  },
  "urls": "http://0.0.0.0:5000"
}