Is Your Local Dev Environment a Mess?

How .NET Aspire Can Help

Aaron Stannard / October 16, 2025
North Houston .NET User Group

About Me

• CEO @ Petabridge
• Akka.NET co-founder
• 20+ years of .NET (since 2005)
• Chronic skeptic of hype

The Hype Train 🚂

"If you follow Microsoft's big personalities on social media..."

Reality: It's a dev productivity tool. A really good one.

The New Developer Experience

1. Clone the repo ✓
2. Request database access... wait 3 days
3. Schema is in another repo (undocumented)
4. No seed data (ask Jim, he might know)
5. Service A needs Service B (which needs Service C)
6. Shared dev database (someone just truncated your table)
7. Docker Compose from 2019 (doesn't work on ARM Macs)

Week 2: "Are you up and running yet?"

The Dependency Multiplication Problem

Each arrow = configuration + credentials + setup time + potential failure

We've Tried to Fix This Before...

The Developer's Dream

That's it. That's the dream.

The F5 Experience™

var builder = DistributedApplication.CreateBuilder(args);

var postgres = builder.AddPostgres("db")
    .WithDataVolume();  // Data survives restarts!

var app = builder.AddProject<Projects.MyApp>("app")
    .WithReference(postgres)
    .WithReplicas(3);  // Run 3 instances

builder.Build().Run();
    

That's it. Press F5. Everything starts.

How Aspire Works

The Magic Ingredients

All accessible with one F5 press

What Just Happened?

Time from git clone to running app: < 2 minutes

Real-World AppHost

var sqlServer = builder.AddSqlServer("sql", saPassword)
    .WithDataVolume();  // Persistent across restarts

var db = sqlServer.AddDatabase("DrawTogetherDb");

// Run migrations before app starts
var migrationService = builder
    .AddProject<Projects.MigrationService>("migrations")
    .WaitFor(db)
    .WithReference(db);

// Start app only after migrations complete
var app = builder.AddProject<Projects.DrawTogether>("app")
    .WithReplicas(3)
    .WithReference(db)
    .WaitForCompletion(migrationService);
  

Migration Service Pattern

// MigrationService/Program.cs
var context = services
  .GetRequiredService<AppDbContext>();

await context.Database
  .MigrateAsync();

await SeedData(context);

// Signal completion
app.Run();
      

⚠️ Avoiding Vendor Lock-in

// In your app's Program.cs - AVOID THIS!
builder.AddServiceDefaults();
builder.AddSqlServerDbContext<AppContext>("sqldata");
builder.AddRedisCache("cache");

// Magic service discovery & config
// Tightly coupled to Aspire runtime
// How do you deploy without Aspire?
      

// In AppHost - this is fine!
var redis = builder.AddRedis("cache");
app.WithEnvironment("RedisConnection",
    redis.GetConnectionString());

// In your app's Program.cs - standard .NET
services.AddStackExchangeRedisCache(options =>
{
    options.Configuration = config["RedisConnection"];
});
      

Automatic OpenTelemetry Integration

Structured Logs

Distributed Traces

System & App Metrics

Zero Configuration
Just works out of the box

Real DrawTogether.NET Test Fixture

[Test]
public async Task CanCreateGameSessionAndDraw()
{
    // Start DrawTogether with real SQL Server
    var appHost = await DistributedApplicationTestingBuilder
        .CreateAsync<DrawTogether_AppHost>();

    await using var app = await appHost.BuildAsync();
    await app.StartAsync();

    // Wait for SQL migrations to complete
    await app.WaitForResource("sqlserver")
        .WaitForHealthy();

    // Connect with real SignalR client
    var blazorApp = app.CreateHttpClient("drawtogether");
    var hubConnection = new HubConnectionBuilder()
        .WithUrl($"{blazorApp.BaseAddress}draw-hub")
        .Build();

    await hubConnection.StartAsync();

    // Real drawing operations, real database persistence
    await hubConnection.InvokeAsync("CreateSession", "TestRoom");
    await hubConnection.InvokeAsync("DrawLine", 10, 10, 50, 50);

    // Verify in real SQL database
    var dbContext = app.Services.GetRequiredService<GameDbContext>();
    var session = await dbContext.Sessions
        .FirstOrDefaultAsync(s => s.Name == "TestRoom");

    Assert.That(session, Is.Not.Null);
}
  

Demo: Integration Testing

• Real DrawTogether integration tests
• Full application spin-up per test
• Parallel test execution
• Automatic cleanup

What Aspire ISN'T (Yet)

"The deployment story is... virtually non-existent"

The Deployment "Story" 📖

Bottom line: Great for dev, figure out prod yourself

Demo: Let's Try Deployment Anyway

# Generate deployment artifacts
aspire generate --output-format docker-compose

# What we get vs what we need
  

Can You Use .NET Aspire?

Smart Adoption Strategy

Remember These Four Things

Resources

Thank You!

Questions?