[Spike] Pipeline generation: Core abstractions and GitHub Actions scheduling

[mitchdenny]

Summary

Spike/proof-of-concept for pipeline generation — the ability to generate CI/CD workflow YAML files (e.g., GitHub Actions) from the Aspire application model.

What's Included

Core Abstractions (Aspire.Hosting)

• IPipelineEnvironment — Marker interface extending IResource for CI/CD environments
• IPipelineStepTarget — Interface for scheduling targets (workflow jobs implement this)
• PipelineEnvironmentCheckAnnotation — Annotation-based environment relevance check
• LocalPipelineEnvironment — Internal fallback for local execution
• PipelineStep.ScheduledBy — Property linking steps to workflow jobs
• GetEnvironmentAsync() — Resolution of active pipeline environment from model

GitHub Actions Package (Aspire.Hosting.Pipelines.GitHubActions)

• GitHubActionsWorkflowResource — Resource + IPipelineEnvironment representing a workflow
• GitHubActionsJob — Job within a workflow, implements IPipelineStepTarget
• GitHubActionsWorkflowExtensions — builder.AddGitHubActionsWorkflow(name) extension
• SchedulingResolver — Projects step DAG onto job dependency graph with cycle detection

Tests (29 total)

• 7 environment resolution tests (fallback, single match, ambiguity, late-added resources)
• 9 workflow resource model tests
• 13 scheduling resolver tests (fan-out, fan-in, diamond, cycles, default job, mixed)

Spec Document

• docs/specs/pipeline-generation.md — Full architecture, API primitives, and future roadmap

Example Usage

var workflow = builder.AddGitHubActionsWorkflow("deploy");
var publishJob = workflow.AddJob("publish");
var deployJob = workflow.AddJob("deploy");

builder.Pipeline.AddStep("build-images", BuildImagesAsync, scheduledBy: publishJob);
builder.Pipeline.AddStep("deploy-app", DeployAppAsync,
    dependsOn: "build-images", scheduledBy: deployJob);

Not Yet Implemented

• YAML generation (aspire pipeline init)
• State upload/download between jobs
• aspire do --continue --job <jobId> CLI support
• Azure DevOps provider

Related

See docs/specs/pipeline-generation.md for full design details and open questions.

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 15643

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 15643"

[github-actions]

Re-running the failed jobs in the CI workflow for this pull request because 1 job was identified as retry-safe transient failures in the CI run attempt.
GitHub was asked to rerun all failed jobs for that attempt, and the rerun is being tracked in the rerun attempt.
The job links below point to the failed attempt jobs that matched the retry-safe transient failure rules.

• Tests / Hosting.JavaScript / Hosting.JavaScript (windows-latest) - Post-test cleanup steps 'Upload logs, and test results | Copy CLI E2E recordings for upload | Upload CLI E2E recordings | Generate test results summary | Post Checkout code' matched the Windows process initialization failure override allowlist.