Optimize Dockerfile: Avoid duplicating pip install across stages

[coderabbitai]

Background

In PR #342, a multi-stage Dockerfile was introduced for the FastAPI application. The current implementation duplicates the pip install step in both the build and runtime stages.

Suggested Improvement

Leverage the build stage to prepare wheels, then install from that wheelhouse in the runtime stage to speed up builds and reduce image size.

Proposed Changes

# In the build stage:
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+COPY requirements.txt .
+RUN pip wheel --no-cache --no-deps -r requirements.txt -w /app/wheelhouse

# In the runtime stage:
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+COPY requirements.txt .
+COPY --from=build /app/wheelhouse /app/wheelhouse
+RUN pip install --no-cache-dir --no-index --find-links /app/wheelhouse -r requirements.txt

Benefits

• Faster build times
• Reduced image size
• Better caching in CI/CD pipelines

References

• PR: feat: add multi-stage Dockerfile for building and running app #342
• Discussion: feat: add multi-stage Dockerfile for building and running app #342 (comment)