Momentum.ServiceDefaults 0.0.1

Momentum.ServiceDefaults

Service defaults for Momentum apps providing common configurations for Aspire-based services including Kafka, PostgreSQL, OpenTelemetry, Serilog, resilience patterns, and service discovery. Essential for all Momentum host projects.

Overview

The Momentum.ServiceDefaults package provides a comprehensive set of default configurations for .NET Aspire-based services. It establishes consistent patterns for observability, messaging, data access, resilience, and service discovery across all Momentum applications.

Installation

Add the package to your project using the .NET CLI:

dotnet add package Momentum.ServiceDefaults

Or using the Package Manager Console:

Install-Package Momentum.ServiceDefaults

Key Features

• Aspire Integration: Complete .NET Aspire service defaults implementation
• Observability Stack: OpenTelemetry + Serilog for comprehensive monitoring
• Messaging Infrastructure: WolverineFx with PostgreSQL event sourcing
• Database Access: PostgreSQL configuration with Npgsql
• Resilience Patterns: HTTP resilience policies and circuit breakers
• Service Discovery: Built-in service resolution and health checks
• Validation: FluentValidation integration and dependency injection

Getting Started

Prerequisites

• .NET 9.0 or later
• ASP.NET Core 9.0 or later (includes Microsoft.AspNetCore.App framework reference)

Basic Setup

Minimal API Example

// Program.cs
var builder = WebApplication.CreateBuilder(args);

// Add service defaults - configures all common services
builder.AddServiceDefaults();

// Add your application-specific services
builder.Services.AddScoped<IUserService, UserService>();

var app = builder.Build();

// Map default endpoints (health checks, metrics, etc.)
app.MapDefaultEndpoints();

// Add your application routes
app.MapGet("/api/users", (IUserService userService) =>
    userService.GetUsersAsync());

app.Run();

Worker Service Example

// Program.cs
var builder = Host.CreateApplicationBuilder(args);

// Add service defaults for background services
builder.AddServiceDefaults();

// Add your worker services
builder.Services.AddHostedService<OrderProcessingWorker>();

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

Configuration

What Gets Configured

When you call AddServiceDefaults(), the following services are automatically configured:

1. Health Checks

• Endpoints: /health (detailed) and /alive (simple)
• Built-in Checks: Database connectivity, messaging health
• Custom Checks: Extensible health check system

// Automatically available endpoints:
// GET /health     - Detailed health status
// GET /alive      - Simple alive check

2. OpenTelemetry Observability

• Metrics: Application and infrastructure metrics
• Tracing: Distributed request tracing
• Logging: Structured logging with correlation

// Configuration includes:
// - ASP.NET Core instrumentation
// - HTTP client instrumentation
// - Runtime metrics
// - GrPC client instrumentation
// - OTLP exporter for telemetry data

3. Serilog Structured Logging

• Integration: OpenTelemetry correlation
• Enrichment: Request context and exceptions
• Sinks: Console and OpenTelemetry sinks

// Logging configuration:
// - Structured JSON output
// - Exception details with Serilog.Exceptions
// - Correlation IDs and trace context

4. Service Discovery

• Resolution: Automatic service endpoint resolution
• Load Balancing: Built-in load balancing strategies
• Health-aware: Integrates with health check system

5. HTTP Resilience

• Policies: Retry, circuit breaker, timeout patterns
• Configuration: Adaptive resilience strategies
• Observability: Resilience metrics and logging

Connection Strings

Configure your services using standard connection string patterns:

// appsettings.json
{
    "ConnectionStrings": {
        "Database": "Host=localhost;Database=myapp;Username=postgres;Password=password",
        "Messaging": "localhost:9092"
    }
}

OpenTelemetry Configuration

Control observability settings:

// appsettings.json
{
    "OpenTelemetry": {
        "ServiceName": "MyApp",
        "ServiceVersion": "1.0.0",
        "Endpoint": "http://localhost:4317"
    },
    "Logging": {
        "LogLevel": {
            "Default": "Information",
            "Microsoft.AspNetCore": "Warning",
            "System": "Warning"
        }
    }
}

Advanced Configuration

Custom Health Checks

Add application-specific health checks:

var builder = WebApplication.CreateBuilder(args);

builder.AddServiceDefaults();

// Add custom health checks
builder.Services.AddHealthChecks()
    .AddCheck<ExternalApiHealthCheck>("external-api")
    .AddCheck<CacheHealthCheck>("redis-cache");

Custom Telemetry

Extend OpenTelemetry configuration:

var builder = WebApplication.CreateBuilder(args);

builder.AddServiceDefaults();

// Add custom telemetry
builder.Services.Configure<OpenTelemetryOptions>(options =>
{
    options.AddSource("MyApp.CustomActivities");
});

WolverineFx Message Handling

Configure messaging with WolverineFx:

var builder = WebApplication.CreateBuilder(args);

builder.AddServiceDefaults();

// WolverineFx is automatically configured with PostgreSQL persistence
// Add your message handlers
builder.Services.AddScoped<OrderCreatedHandler>();
builder.Services.AddScoped<PaymentProcessedHandler>();

var app = builder.Build();
app.MapDefaultEndpoints();
app.Run();

Custom Resilience Policies

Customize HTTP resilience:

var builder = WebApplication.CreateBuilder(args);

builder.AddServiceDefaults();

// Customize resilience for specific HTTP clients
builder.Services.AddHttpClient<ExternalApiClient>(client =>
{
    client.BaseAddress = new Uri("https://api.external.com");
})
.AddResilienceHandler("external-api", static builder =>
{
    builder.AddRetry(new RetryStrategyOptions
    {
        MaxRetryAttempts = 3,
        BackoffType = DelayBackoffType.Exponential
    });
});

Environment-Specific Configuration

Development

// appsettings.Development.json
{
    "ConnectionStrings": {
        "Database": "Host=localhost;Database=myapp_dev;Username=postgres;Password=dev123"
    },
    "OpenTelemetry": {
        "Endpoint": "http://localhost:4317"
    },
    "Logging": {
        "LogLevel": {
            "Default": "Debug"
        }
    }
}

Production

// appsettings.Production.json
{
    "ConnectionStrings": {
        "Database": "Host=prod-db;Database=myapp;Username=app_user;Password=${DB_PASSWORD}"
    },
    "OpenTelemetry": {
        "Endpoint": "https://telemetry.company.com"
    },
    "Logging": {
        "LogLevel": {
            "Default": "Information",
            "Microsoft": "Warning"
        }
    }
}

Integrated Dependencies

This package includes comprehensive integrations with:

Target Frameworks

• .NET 9.0: Primary target framework
• ASP.NET Core 9.0: Includes framework reference for web applications
• Compatible with all .NET Aspire host types

Use Cases

This package is essential for:

• API Services: REST and gRPC API projects
• Background Services: Worker services and hosted services
• Orleans Silos: Actor-based stateful services
• Message Processors: Event-driven microservices
• Any Aspire Host: All .NET Aspire-based applications

Related Packages

• Momentum.ServiceDefaults.Api - API-specific extensions
• Momentum.Extensions.Messaging.Kafka - Kafka messaging
• Momentum.Extensions - Core utilities and abstractions

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contributing

For contribution guidelines and more information about the Momentum platform, visit the main repository.