ihp-railiance-probe/INTENT.md

ihp-railiance-probe — Intent

Purpose

ihp-railiance-probe is a minimal, test-first IHP application whose sole purpose is to validate the complete build-to-deployment pipeline for IHP-on-Railiance before any production workload runs through it.

It is a probe — not a product. Every decision favours diagnostic speed over feature richness.

Why it exists

Building inter-hub revealed two classes of expensive problems:

1. Build-time surprises — GHC 9.10.3 bugs (oversized .hi files, truncated static archives) that only manifest in production (nix build .#docker), not in the development GHCi loop. Debugging these inside a 477-module codebase cost many build cycles and hours of iteration.

2. Pipeline unknowns — The full chain (haskelseed build → Gitea registry push → Railiance01 Kubernetes deployment) had never been exercised end-to-end in a clean, reproducible way before inter-hub attempted production.

A minimal probe surfaces both problem classes on a trivially small codebase where failures are cheap to diagnose and fix.

Success criteria

The probe is complete when all of the following hold without manual intervention:

#	Check	Verified by
1	nix build .#docker succeeds on haskelseed	Zero-error build log
2	OCI image pushed to 92.205.130.254:32166/coulomb/ihp-railiance-probe:SHA	skopeo inspect
3	Helm chart deploys pod to Railiance01	kubectl get pods — Running
4	Health endpoint responds	curl /healthz → 200
5	At least one Hspec integration test passes in CI	test command green

Design constraints

• Minimal schema: one table (probes) with id, name, created_at. Enough to exercise the IHP code-gen path without generating hundreds of modules.
• Test-first: every controller action has a corresponding Hspec test before it is implemented.
• Diagnostic-first flake: flake.nix starts from the hard-won inter-hub overlay (ActualTypes.hi fix, haskelseed resource limits) so GHC 9.10.3 quirks are handled from day one.
• No application logic: the probe is a canary. Application features belong in inter-hub or its successors.

Relationship to inter-hub

ihp-railiance-probe is upstream in confidence, not in code. A successful probe means:

• The Nix/GHC/cabal production build is healthy for the current flake lock.
• The Gitea registry + Railiance01 deployment chain is operational.
• A new IHP project can be promoted to production without the build archaeology that inter-hub required.

Once the pipeline is validated, the probe continued as a regression canary until Core Hub replaced the production interaction framework.

Retirement (2026-07-07)

Archived per CORE-WP-0007-T01 after IRP-WP-0001 completion and Core Hub production cutover (CORE-WP-0005-T04, 2026-07-03). The probe's diagnostic value is preserved in this repo's docs and workplan archive; no further builds or deployments are expected. Haskell build-lane retirement continues in CORE-WP-0007-T03.