github: build understack-tests container too

Author: skrobul

.github/workflows/containers.yaml

@@ -126,6 +126,7 @@ jobs:
           - name: ironic-nautobot-client
           - name: nova-flavors
           - name: ansible
+          - name: understack-tests
 
     steps:
       - name: setup docker buildx
@@ -186,6 +187,7 @@ jobs:
           - ironic-nautobot-client
           - nova-flavors
           - ansible
+          - understack-tests
 
     steps:
       - name: clean up PR container

containers/understack-tests/Dockerfile.understack-tests

@@ -1,16 +1,18 @@
-FROM python:3.12-slim
+FROM python:3.12-slim AS builder
 ENV UV_PYTHON_DOWNLOADS=never
 ENV UV_COMPILE_BYTECODE=1
 ENV PATH="/code/.venv/bin:/code/.bin:$PATH"
 
 WORKDIR /code
-
 COPY --from=ghcr.io/astral-sh/uv:latest /uv /bin/uv
-
 COPY python/understack-tests/uv.lock python/understack-tests/pyproject.toml /code/
 RUN --mount=type=cache,target=/root/.cache/uv uv sync --verbose --locked --no-dev
 COPY python/understack-tests /code
 
+
+FROM builder AS prod
+WORKDIR /code
+COPY --from=builder /code /code
 RUN useradd --create-home app
 COPY --chown=app:app containers/understack-tests/rally.conf /home/app/.rally/rally.conf
 USER app