aspire-configuration

Aspire Configuration

When to Use This Skill

Use this skill when:

• Wiring AppHost resources to application configuration in Aspire-based repos
• Ensuring production configuration is transparent and portable outside of Aspire
• Avoiding Aspire client/service-discovery packages inside application code
• Designing feature toggles for dev/test without changing app code paths

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Core Principles

1. AppHost owns Aspire infrastructure packages

   • Aspire Hosting packages belong in AppHost only.
   • App projects should not reference Aspire client/service-discovery packages.

2. Explicit configuration only

   • AppHost must translate resource outputs into explicit config keys (env vars).
   • App code binds to IOptions<T> or Configuration only.

3. Production parity and transparency

   • Every value injected by AppHost must be representable in production as env vars or config files without Aspire.
   • Avoid opaque service discovery and implicit configuration.

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Configuration Flow

AppHost resource -> WithEnvironment(...) -> app config keys -> IOptions<T> in app

The AppHost is responsible for turning Aspire resources into explicit app settings. The application never consumes Aspire clients or service discovery directly.

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AppHost Patterns (Explicit Mapping)

Example: Database + Blob Storage

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

var postgres = builder.AddPostgres("postgres");
var db = postgres.AddDatabase("appdb");

var minio = builder.AddContainer("minio", "minio/minio")
    .WithArgs("server", "/data")
    .WithHttpEndpoint(targetPort: 9000, name: "http")
    .WithHttpEndpoint(targetPort: 9001, name: "console")
    .WithEnvironment("MINIO_ROOT_USER", "minioadmin")
    .WithEnvironment("MINIO_ROOT_PASSWORD", "minioadmin");

var api = builder.AddProject<Projects.MyApp_Api>("api")
    .WithReference(db, "Postgres")
    .WithEnvironment("BlobStorage__Enabled", "true")
    .WithEnvironment("BlobStorage__ServiceUrl", minio.GetEndpoint("http"))
    .WithEnvironment("BlobStorage__AccessKey", "minioadmin")
    .WithEnvironment("BlobStorage__SecretKey", "minioadmin")
    .WithEnvironment("BlobStorage__Bucket", "attachments")
    .WithEnvironment("BlobStorage__ForcePathStyle", "true");

builder.Build().Run();