Intropy.Topology.Aspire 0.4.6

Intropy.Topology.Aspire

The .NET Aspire run backend for Intropy.Topology.

It turns a validated SystemTopology into a local, F5-able Aspire application with Dapr. At AppHost startup it:

1. discovers the validated system definition from the supplied assembly;
2. generates Dapr components and per-component runtime configuration into a temporary directory; and
3. translates the topology to Aspire resources: one Redis container for pub/sub and one sibling .NET project plus Dapr sidecar for each topology component.

The adapter is deliberately one-way: Aspire receives ordinary resources; it does not need to understand the topology model.

Usage

One SystemHost entry point selects the run or generation backend from the same discovered system definition:

using System.Reflection;
using Intropy.Topology.Aspire;
using Intropy.Topology.Generation;

var assembly = Assembly.GetExecutingAssembly();
return args is ["run", ..] or []
    ? await IntropyAspire.RunAsync(assembly, args)     // Aspire + DCP
    : await IntropyGenerate.RunAsync(assembly, args);  // generate | check | graph

Project convention

Each topology component is resolved to a sibling project relative to the SystemHost:

• order-extractor resolves to ../order-extractor/src/*.csproj when src contains exactly one project;
• otherwise it resolves to ../order-extractor/order-extractor.csproj.

A component's standalone Dapr resources live at ../<component>/local/dapr-components/. For Aspire runs, they are staged with generated resources at the stable, inspectable path obj/dapr-components/<component>/; generated resources replace local resources with the same Dapr metadata.name.

Runtime behavior

• Redis backs development pub/sub. It is published at host port 6380 because generated Dapr resources target localhost:6380; dapr init commonly reserves Redis's default 6379.
• Components receive INTROPY__COMPONENT and INTROPY__CONFIG environment variables. The latter points to that component's generated .intropy.json file.
• A publisher waits for its subscribers during startup when the topic graph is acyclic. Dapr sidecars also wait for Redis readiness before they start.
• Extractors and transactional integrations run to completion: the framework runners (RunToCompletionRunner, TransactionalIntegrationRunner) shut the Dapr sidecar down when the run ends, so a Finished/Exited resource state is a completed run, not a failure. Their sidecars are exempt from the host's sidecar-recovery restarts; a resident component's (a loader's) early sidecar exit is still recovered.
• A transactional integration's internal hop — its receive pipeline publishing to a component-owned topic and its send pipeline subscribing to it — is minted by the topology as the component's InternalQueue (internal-<component> pubsub, hop topic). It is workload shape, not an inter-component edge, so it never appears in Publishes/Subscribes or SystemTopology.Topics, and the topic completeness rules neither see nor warn about it. Generation emits its pubsub component (Redis, scoped to exactly the owning component) and carries the names in the component's .intropy.json; the framework runner defaults TransactionalIntegrationOptions.DaprPubSubName/DaprTopicName from that config. No local/dapr-components/ entry is required.

Prerequisites

• An AppHost project using the .NET Aspire SDK.
• Docker.
• The Dapr CLI initialized locally: dapr init.

Scope

This package implements the repository's minimal topology model. Development overrides, external-system mocks, Microcks, API mocking, and additional transport/runtime backends remain on the full-topology branch; they are not supported here.