fix: port mapping for railway deployment

[varit05]

Summary by CodeRabbit

• Chores
  • Updated container startup configuration to support dynamic port assignment through the PORT environment variable, maintaining a default value of 8501.

[coderabbitai]

📝 Walkthrough

Walkthrough

The Dockerfile's CMD instruction converts from exec-form JSON array to shell-form string syntax, enabling environment variable expansion for the Streamlit server port parameter with a default fallback of 8501 instead of a hard-coded value.

Changes

Docker Runtime Configuration

Layer / File(s)	Summary
CMD Instruction Dockerfile	CMD changes from exec-form ["streamlit","run","ui/app.py","--server.port=8501","--server.address=0.0.0.0"] to shell-form streamlit run ui/app.py --server.port=${PORT:-8501} --server.address=0.0.0.0 to allow PORT environment variable override with 8501 default.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

Poem

🐰 A port once carved in stone so deep,
Now bends its ear to whispers we keep—
The shell expands what JSON could not,
And ${PORT:-8501} claims its new slot!
Flexibility blooms where defaults still stay. 🌱

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: updating the Dockerfile to use environment variable expansion for port mapping to support Railway deployment configuration.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/port-mapping-for-railway-deployment

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[coderabbitai]

🧹 Nitpick comments (1)

Dockerfile (1)

51-51: ⚡ Quick win

Add exec to the shell-form CMD to prevent signal handling issues with tini.

Line 51 uses shell-form CMD, which Docker converts to ["/bin/sh", "-c", "..."] under the exec-form tini ENTRYPOINT. The /bin/sh process at PID 2 does not forward signals properly to Streamlit. The exec keyword fixes this by replacing the shell with Streamlit directly.

Suggested change

-CMD streamlit run ui/app.py --server.port=${PORT:-8501} --server.address=0.0.0.0
+CMD ["sh", "-c", "exec streamlit run ui/app.py --server.port=\"${PORT:-8501}\" --server.address=0.0.0.0"]

For maximum robustness, consider an entrypoint script instead to avoid the intermediate shell entirely (e.g., ENTRYPOINT ["tini", "--"] with CMD ["/app/entrypoint.sh"] that performs variable expansion and execs Streamlit).

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@Dockerfile` at line 51, The Dockerfile's shell-form CMD starting with "CMD
streamlit run ui/app.py ..." causes /bin/sh (spawned by the tini ENTRYPOINT) to
sit between PID 1 and the Streamlit process and not forward signals; update the
Dockerfile so the CMD uses exec to replace the shell and directly launch
Streamlit (e.g., prepend "exec" to the existing shell-form command) or, better,
switch to exec-form JSON CMD/ENTRYPOINT to run Streamlit directly (reference the
existing CMD line and the ui/app.py invocation and ensure tini remains as
ENTRYPOINT so signals are delivered to the Streamlit process).

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@Dockerfile`:
- Line 51: The Dockerfile's shell-form CMD starting with "CMD streamlit run
ui/app.py ..." causes /bin/sh (spawned by the tini ENTRYPOINT) to sit between
PID 1 and the Streamlit process and not forward signals; update the Dockerfile
so the CMD uses exec to replace the shell and directly launch Streamlit (e.g.,
prepend "exec" to the existing shell-form command) or, better, switch to
exec-form JSON CMD/ENTRYPOINT to run Streamlit directly (reference the existing
CMD line and the ui/app.py invocation and ensure tini remains as ENTRYPOINT so
signals are delivered to the Streamlit process).

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: e5c225a6-e8d4-40ad-8c50-e84d4427e047

📥 Commits

Reviewing files that changed from the base of the PR and between 3dd75d4 and d760595.

📒 Files selected for processing (1)

• Dockerfile