feat(credit): bake-image local CSS serve demo (#173)

credit/Dockerfile.serve.demo

@@ -0,0 +1,31 @@
+# Credit CSS FastAPI — demo bake image (joblib inside the image, no volume).
+# Build from repo root AFTER preparing the artifact:
+#   ./platform/scripts/prepare-serve-demo-artifact.sh
+#   docker build -f credit/Dockerfile.serve.demo -t credit-css-serve-demo .
+# Run (no -v mount):
+#   docker run --rm -p 8000:8000 credit-css-serve-demo
+#
+# Local volume-mount serving stays on credit/Dockerfile.serve.
+
+FROM python:3.11-slim-bookworm
+
+WORKDIR /app
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends build-essential \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY pyproject.toml poetry.lock README.md ./
+COPY src ./src
+COPY credit ./credit
+
+RUN pip install --no-cache-dir poetry \
+    && poetry config virtualenvs.create false \
+    && poetry install --only main --no-ansi --no-interaction
+
+# Baked hermetic fit output (gitignored under credit/demo_artifact/).
+COPY credit/demo_artifact/pipeline.joblib /artifact/pipeline.joblib
+ENV CREDIT_PIPELINE_ARTIFACT=/artifact/pipeline.joblib
+EXPOSE 8000
+
+CMD ["uvicorn", "credit.api:create_app", "--factory", "--host", "0.0.0.0", "--port", "8000"]

credit/docs/features/aws-fargate-serve-demo.md

@@ -1,11 +1,11 @@
 # Feature: Ephemeral CSS FastAPI serve on AWS (Fargate)
 
-**Status:** planned — docs lock in progress (#172); bake-image (#173) then AWS HITL (#174)  
+**Status:** in progress — docs done (#172); **bake-image (#173) in this cut**; AWS HITL (#174) next  
 **GitHub:** parent [#171](https://github.com/JLaborda/SmartWealthAI/issues/171) · [#172](https://github.com/JLaborda/SmartWealthAI/issues/172) docs · [#173](https://github.com/JLaborda/SmartWealthAI/issues/173) bake-image · [#174](https://github.com/JLaborda/SmartWealthAI/issues/174) AWS up/down  
 **Domain:** credit / CSS (demo surface) + shared `platform/` (IaC)  
 **Glossary:** [`../../CONTEXT.md`](../../CONTEXT.md) (domain only — no AWS terms) · Map: [`../../../CONTEXT-MAP.md`](../../../CONTEXT-MAP.md)  
-**Related:** chapter 5 [`css-chapter5-mart-and-scoring.md`](css-chapter5-mart-and-scoring.md) · PSI [`psi-data-drift.md`](psi-data-drift.md) · Friday MUST [`../guides/friday-demo.md`](../guides/friday-demo.md) · [ADR-0004](../../../docs/adr/0004-platform-ephemeral-fargate-serve.md)  
-**Code (target):** `platform/terraform/credit-css-serve-demo/`, `platform/scripts/demo-up.sh`, `platform/scripts/demo-down.sh`, `credit/Dockerfile.serve.demo`
+**Related:** chapter 5 [`css-chapter5-mart-and-scoring.md`](css-chapter5-mart-and-scoring.md) · PSI [`psi-data-drift.md`](psi-data-drift.md) · Friday MUST [`../guides/friday-demo.md`](../guides/friday-demo.md) · [ADR-0004](../../../docs/adr/0004-platform-ephemeral-fargate-serve.md) · bake guide [`../guides/serve-fastapi.md`](../guides/serve-fastapi.md)  
+**Code:** `credit/demo_serve_artifact.py`, `credit/Dockerfile.serve.demo`, `platform/scripts/prepare-serve-demo-artifact.sh` · Tests: `tests/credit/test_serve_demo_bake.py` · Later: `platform/terraform/credit-css-serve-demo/`, `demo-up.sh` / `demo-down.sh`
 
 ## Problem Statement
 
@@ -66,11 +66,12 @@ No S3 data lake, no auth, no GitHub CD in this cut.
 
 ## Acceptance criteria
 
-- [ ] Feature spec + ADR-0004 + friday-demo stretch link exist in English
-- [ ] With a valid `AWS_PROFILE`, `demo-up` yields reachable `/health` and successful `/score` + `/drivers` using existing serving fixtures
-- [ ] `demo-down` destroys the stack including ECR images
-- [ ] Local volume-mount serve Docker path remains documented and unchanged in behaviour
-- [ ] No AWS vocabulary added to `credit/CONTEXT.md`
+- [x] Feature spec + ADR-0004 + friday-demo stretch link exist in English (#172)
+- [x] Bake-image local path: `prepare-serve-demo-artifact` + `Dockerfile.serve.demo` + hermetic pytest + documented docker smoke without volume (#173)
+- [ ] With a valid `AWS_PROFILE`, `demo-up` yields reachable `/health` and successful `/score` + `/drivers` using existing serving fixtures (#174)
+- [ ] `demo-down` destroys the stack including ECR images (#174)
+- [x] Local volume-mount serve Docker path remains documented and unchanged in behaviour
+- [x] No AWS vocabulary added to `credit/CONTEXT.md`
 
 ## Out of Scope
 

credit/docs/guides/serve-fastapi.md

@@ -58,7 +58,7 @@ curl -s localhost:8000/drivers \
   -d @tests/credit/fixtures/serving/drivers_request.json
 ```
 
-## Docker
+## Docker (volume mount)
 
 ```bash
 docker build -f credit/Dockerfile.serve -t credit-css-serve .
@@ -68,6 +68,18 @@ docker run --rm -p 8000:8000 \
   credit-css-serve
 ```
 
+## Docker (bake-image demo — no volume)
+
+Hermetic fit into gitignored `credit/demo_artifact/`, then an image that embeds `pipeline.joblib` (for local smoke and later Fargate). Spec: [`../features/aws-fargate-serve-demo.md`](../features/aws-fargate-serve-demo.md) (#173).
+
+```bash
+./platform/scripts/prepare-serve-demo-artifact.sh
+docker build -f credit/Dockerfile.serve.demo -t credit-css-serve-demo .
+docker run --rm -p 8000:8000 credit-css-serve-demo
+```
+
+Same curls as above (no `-v`). Volume-mount `Dockerfile.serve` remains the default local path.
+
 ## Out of this guide
 
-PSI CLI, Terraform/AWS, SHAP on drivers — later Friday-demo slices.
+PSI CLI, Terraform/AWS up-down (#174), SHAP on drivers — later slices.

credit/src/credit/demo_serve_artifact.py

@@ -0,0 +1,54 @@
+"""Prepare a hermetic ``pipeline.joblib`` for the bake-image serve demo (#173)."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from credit.application_mart import build_application_mart
+from credit.scoring_pipeline import ARTIFACT_NAME, fit_scoring_pipeline
+
+# Default relative to repo root when callers pass only output_dir via the script.
+DEFAULT_SCORING_FIXTURE = (
+    Path(__file__).resolve().parents[3]
+    / "tests"
+    / "credit"
+    / "fixtures"
+    / "scoring_mart"
+    / "applications.csv"
+)
+
+
+def prepare_serve_demo_artifact(
+    output_dir: Path,
+    *,
+    source: Path | None = None,
+) -> Path:
+    """Fit a CSS pipeline into ``output_dir`` and return the joblib path.
+
+    Uses the hermetic scoring fixture unless ``source`` is provided. Mart
+    intermediates go under ``output_dir / "_mart"``.
+    """
+    output_dir = Path(output_dir)
+    output_dir.mkdir(parents=True, exist_ok=True)
+    source_path = Path(source) if source is not None else DEFAULT_SCORING_FIXTURE
+
+    mart = build_application_mart(
+        source_path,
+        output_dir / "_mart",
+        application_id_column="customer_ID",
+        target_column="target",
+        bad_value=1,
+        good_value=0,
+    )
+    fit_scoring_pipeline(
+        mart.mart_path,
+        output_dir,
+        application_id_column="customer_ID",
+        target_column="target",
+        random_state=42,
+        skip_mlflow=True,
+    )
+    artifact = output_dir / ARTIFACT_NAME
+    if not artifact.is_file():
+        raise FileNotFoundError(f"Expected artifact missing: {artifact}")
+    return artifact

platform/README.md

@@ -0,0 +1,11 @@
+# Platform
+
+Shared AWS / Terraform and operator scripts. Domain language stays in `credit/` and investing docs — see [`CONTEXT-MAP.md`](../CONTEXT-MAP.md) and [ADR-0004](../docs/adr/0004-platform-ephemeral-fargate-serve.md).
+
+## Scripts (credit CSS serve demo)
+
+| Script | Purpose |
+| --- | --- |
+| `scripts/prepare-serve-demo-artifact.sh` | Hermetic fit → `credit/demo_artifact/pipeline.joblib` for `credit/Dockerfile.serve.demo` (#173) |
+
+AWS `demo-up` / `demo-down` land with [#174](https://github.com/JLaborda/SmartWealthAI/issues/174).

platform/scripts/prepare-serve-demo-artifact.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Hermetic fit → credit/demo_artifact/pipeline.joblib for Dockerfile.serve.demo (#173).
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "$0")/../.." && pwd)"
+cd "$ROOT"
+
+OUT="${CREDIT_DEMO_ARTIFACT_DIR:-$ROOT/credit/demo_artifact}"
+
+poetry run python -c "
+from pathlib import Path
+from credit.demo_serve_artifact import prepare_serve_demo_artifact
+path = prepare_serve_demo_artifact(Path(r'''$OUT'''))
+print(path)
+"

tests/credit/test_serve_demo_bake.py

@@ -0,0 +1,75 @@
+"""Seam A: prepare demo artifact → FastAPI score/drivers (bake path, no Docker)."""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import pytest
+from fastapi.testclient import TestClient
+
+from credit.scoring_pipeline import ARTIFACT_NAME
+
+EXAMPLE_PAYLOAD = Path(__file__).parent / "fixtures" / "serving" / "score_request.json"
+DRIVERS_PAYLOAD = Path(__file__).parent / "fixtures" / "serving" / "drivers_request.json"
+SCORING_FIXTURE = Path(__file__).parent / "fixtures" / "scoring_mart" / "applications.csv"
+
+
+def test_prepare_serve_demo_artifact_serves_score_and_drivers(tmp_path: Path) -> None:
+    """Hermetic prepare → joblib under output_dir → /score and /drivers succeed."""
+    from credit.api import create_app
+    from credit.demo_serve_artifact import prepare_serve_demo_artifact
+
+    artifact = prepare_serve_demo_artifact(
+        tmp_path / "demo_artifact",
+        source=SCORING_FIXTURE,
+    )
+    assert artifact == tmp_path / "demo_artifact" / ARTIFACT_NAME
+    assert artifact.is_file()
+
+    client = TestClient(create_app(artifact_path=artifact))
+    score_body = json.loads(EXAMPLE_PAYLOAD.read_text(encoding="utf-8"))
+    drivers_body = json.loads(DRIVERS_PAYLOAD.read_text(encoding="utf-8"))
+
+    score = client.post("/score", json=score_body)
+    assert score.status_code == 200, score.text
+    score_payload = score.json()
+    assert score_payload["application_id"] == score_body["application_id"]
+    assert 0.0 <= score_payload["pd"] <= 1.0
+    assert 250.0 <= score_payload["credit_score"] <= 1000.0
+
+    drivers = client.post("/drivers", json=drivers_body)
+    assert drivers.status_code == 200, drivers.text
+    drivers_payload = drivers.json()
+    assert drivers_payload["method"] == "gain_x_abs_woe"
+    assert len(drivers_payload["drivers"]) == drivers_body["top_k"]
+
+
+def test_prepare_uses_default_scoring_fixture_when_source_omitted(
+    tmp_path: Path,
+) -> None:
+    """Operator script path: no ``source`` → DEFAULT_SCORING_FIXTURE."""
+    from credit.demo_serve_artifact import (
+        DEFAULT_SCORING_FIXTURE,
+        prepare_serve_demo_artifact,
+    )
+
+    assert DEFAULT_SCORING_FIXTURE.is_file()
+    artifact = prepare_serve_demo_artifact(tmp_path / "demo_default")
+    assert artifact == tmp_path / "demo_default" / ARTIFACT_NAME
+    assert artifact.is_file()
+
+
+def test_prepare_raises_when_fit_skips_writing_joblib(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Fail clearly if fit returns without ``pipeline.joblib``."""
+    from credit import demo_serve_artifact as mod
+
+    monkeypatch.setattr(
+        mod,
+        "fit_scoring_pipeline",
+        lambda *a, **k: None,
+    )
+    with pytest.raises(FileNotFoundError, match="Expected artifact missing"):
+        mod.prepare_serve_demo_artifact(tmp_path / "empty", source=SCORING_FIXTURE)