add Dockerfile to run backend

Author: TimChild

clerk_api_demo/Dockerfile

@@ -0,0 +1,44 @@
+## https://github.com/astral-sh/uv-docker-example/blob/main/standalone.Dockerfile
+
+# Using uv image with explicitly managed python
+FROM ghcr.io/astral-sh/uv:bookworm-slim AS builder
+ENV UV_COMPILE_BYTECODE=1 UV_LINK_MODE=copy
+
+# Configure the Python directory so it is consistent
+ENV UV_PYTHON_INSTALL_DIR /python
+
+# Only use the managed Python version
+ENV UV_PYTHON_PREFERENCE=only-managed
+
+# Install Python before the project for caching
+RUN uv python install 3.13
+
+WORKDIR /app
+RUN --mount=type=cache,target=/root/.cache/uv \
+    --mount=type=bind,source=uv.lock,target=uv.lock \
+    --mount=type=bind,source=pyproject.toml,target=pyproject.toml \
+    uv sync --frozen --no-install-project --no-dev
+
+COPY clerk_api_demo clerk_api_demo
+COPY pyproject.toml .
+COPY uv.lock .
+COPY rxconfig.py .
+
+RUN --mount=type=cache,target=/root/.cache/uv \
+    uv sync --frozen --no-dev
+
+# Then, use a final image without uv (note this also doesn't include python)
+FROM debian:bookworm-slim
+
+# Copy the Python installed in the builder
+COPY --from=builder --chown=python:python /python /python
+
+# Copy the application from the builder
+COPY --from=builder --chown=app:app /app /app
+
+# Place executables in the environment at the front of the path
+ENV PATH="/app/.venv/bin:$PATH"
+
+##########
+WORKDIR /app
+CMD ["reflex", "run", "--env", "prod", "--backend-only", "--loglevel", "info"]