Nabs.Launchpad.Core.Silo 10.0.213

Nabs Launchpad Core Silo Library

A .NET 10 library providing Orleans silo hosting capabilities and configuration for distributed computing in the Nabs Launchpad framework.

Overview

The Nabs.Launchpad.Core.Silo library enables hosting Microsoft Orleans silos with pre-configured clustering, persistence, and authorization features. Orleans is a cross-platform framework for building robust, scalable distributed applications using the Virtual Actor Model.

Key Features

• Orleans Silo Hosting: Complete silo configuration with Azure Table clustering and blob storage persistence
• Authorization Framework: Built-in grain call authorization with anonymous method support
• Orleans Dashboard: Integrated dashboard for monitoring grain activity and cluster status
• Azure Integration: Configured for Azure Table Storage clustering and Azure Blob Storage persistence
• Entity Framework Integration: SQL Server database connectivity through Aspire
• Service Defaults: Integration with Nabs Launchpad service configuration standards

Key Components

ProjectExtensions

The main entry point for configuring Orleans silo services:

public static IHostApplicationBuilder AddSiloServices(
    this IHostApplicationBuilder builder, 
    Action<SiloServicesOptions> siloServicesOptionsSetup)

SiloServicesOptions

Configuration options for the Orleans silo:

public class SiloServicesOptions
{
    // Authorization filter configuration
    public List<string> AuthorizationFilterTypePrefixes { get; set; } = [];
    
    // Orleans cluster configuration
    public string ClusterId { get; set; } = "default";
    public string ServiceId { get; set; } = string.Empty;
    
    // Serialization options
    public OrleansSerializationOptions SerializationOptions { get; } = new();
}

AuthorisationFilter

Grain call authorization filter that:

• Validates user context for protected grain methods
• Supports anonymous methods via [Anonymous] attribute
• Applies to grain interfaces matching configured type prefixes

AnonymousAttribute

Attribute to mark grain methods as not requiring authorization:

[AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = false)]
public class AnonymousAttribute : Attribute

Dependencies

• Microsoft.Orleans.Server: Core Orleans silo functionality
• Microsoft.Orleans.Clustering.AzureStorage: Azure Table Storage clustering
• Microsoft.Orleans.Persistence.AzureStorage: Azure Blob Storage persistence
• OrleansDashboard: Monitoring and administration dashboard
• Aspire.Azure.Data.Tables & Aspire.Azure.Storage.Blobs: Azure service integrations
• Ardalis.Result & Ardalis.Result.FluentValidation: Result pattern support
• Entity Framework Core SQL Server: Database connectivity

Usage Example

Configuring the Silo

var builder = Host.CreateApplicationBuilder(args);

builder.AddSiloServices(options =>
{
    options.ClusterId = "my-cluster";
    options.ServiceId = "my-service";
    options.AuthorizationFilterTypePrefixes.Add("MyApp.Grains.Interfaces");
    options.SerializationOptions.SupportedPrefixes.Add("MyApp.Models");
});

var app = builder.Build();
await app.RunAsync();

Creating Protected Grains

public interface IUserGrain : IGrainWithStringKey
{
    // Requires authorization
    Task<User> GetUserAsync();
    
    // Anonymous access allowed
    [Anonymous]
    Task<bool> CheckHealthAsync();
}

public class UserGrain : Grain, IUserGrain
{
    public Task<User> GetUserAsync()
    {
        // This method requires a valid UserContext in RequestContext
        var userContext = RequestContext.Get("UserContext");
        // Implementation...
    }
    
    public Task<bool> CheckHealthAsync()
    {
        // This method allows anonymous access
        return Task.FromResult(true);
    }
}

Setting User Context (in Gateway/API)

// Before calling grains, set the user context
RequestContext.Set("UserContext", currentUserContext);
var grain = grainFactory.GetGrain<IUserGrain>(userId);
var user = await grain.GetUserAsync();

Authorization Flow

1. Grain Call Initiated: Client calls a grain method
2. Filter Evaluation: AuthorisationFilter checks if the grain interface matches configured prefixes
3. Anonymous Check: Verifies if the method has [Anonymous] attribute
4. User Context Validation: Ensures UserContext exists in RequestContext for protected methods
5. Method Execution: Proceeds with grain method execution if authorized

Integration with Launchpad

This library integrates with other Nabs Launchpad components:

• Core.Interfaces: Provides grain interfaces and shared contracts
• Core.Context: Database context integration for grain persistence
• Core.ServiceDefaults: Common service configuration and observability
• Core.SiloClient: Client-side Orleans configuration for connecting to silos

Azure Configuration

The silo expects the following Azure services to be configured:

• Azure Table Storage: For Orleans clustering (connection key: "clustering")
• Azure Blob Storage: For grain state persistence (connection key: "grain-state")
• SQL Server: For application data persistence

Monitoring

The Orleans Dashboard is automatically configured and available for monitoring:

• Grain activation statistics
• Cluster membership status
• Performance metrics
• Call tracing

Testing

The library includes comprehensive unit tests in the Launchpad.Core.Silo.UnitTests project. For integration testing, use the Nabs.Launchpad.Core.Testing.Silos library which provides test cluster capabilities.

Best Practices

1. Grain Design: Follow Orleans best practices for grain state management
2. Authorization: Use type prefixes to apply authorization selectively
3. Anonymous Methods: Mark health checks and public APIs with [Anonymous]
4. Error Handling: Implement proper error handling in grain methods
5. Resource Management: Use proper disposal patterns for long-running operations

Contributing

This library follows the Nabs Launchpad coding standards:

• Use C# 13 features and latest language constructs
• Follow nullable reference types conventions
• Implement proper async/await patterns
• Include comprehensive unit tests

License

Copyright � Net Advantage Business Solutions