Switch Containerfile CMD with ENTRYPOINT

[frzifus]

Description

See: #227 (comment)

Type of change

• Refactor
• New feature
• Bug fix
• CVE fix
• Optimization
• Documentation Update
• Configuration Update
• Bump-up service version
• Bump-up dependent library
• Bump-up library or tool used for development (does not change the final image)
• CI configuration change
• Konflux configuration change
• Unit tests improvement
• Integration tests improvement
• End to end tests improvement

Related Tickets & Documents

• Related Issue #
• Closes CMD in Dockerfile overrides execution when using Kubernetes args #226

Checklist before requesting a review

• I have performed a self-review of my code.
• PR has passed all pre-merge test jobs.
• If it is a core feature, I have added thorough tests.

Testing

• Please provide detailed steps to perform tests related to this code change.
• How were the fix/results from this change verified? Please provide relevant screenshots or results.

Summary by CodeRabbit

• Chores
  • Updated container startup behavior to ensure the Python application always launches as the entrypoint, with any additional arguments appended at runtime.

[coderabbitai]

Walkthrough

The container configuration was updated to replace the CMD directive with an ENTRYPOINT directive. This change ensures that the Python application is always executed as the primary process, with any additional runtime arguments appended rather than replacing the command.

Changes

File(s)	Change Summary
Containerfile	Replaced CMD with ENTRYPOINT for launching the Python script.

Assessment against linked issues

Objective	Addressed	Explanation
Ensure ENTRYPOINT is used instead of CMD to allow Kubernetes args to be appended, not override execution (#226)	✅

Poem

In a Docker warren, the rabbits did say,
"Let ENTRYPOINT guide us, CMD move away!"
Now Python will start, no matter the args,
Kubernetes and containers, no more snags!
🐇✨

— A happy rabbit, hopping into deployment

---

📜 Recent review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between b074aea and 4b9b39c.

📒 Files selected for processing (1)

• Containerfile (1 hunks)

🔇 Additional comments (1)

Containerfile (1)

54-54: ENTRYPOINT change is safe—argument handling verified

Verified that src/lightspeed_stack.py imports and uses argparse.ArgumentParser, so it already handles command-line arguments. No further action needed.

---

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

• Review comments: Directly reply to a review comment made by CodeRabbit. Example:
  • I pushed a fix in commit <commit_id>, please review it.
  • Explain this complex logic.
  • Open a follow-up GitHub issue for this discussion.
• Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
  • @coderabbitai explain this code block.
  • @coderabbitai modularize this function.
• PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
  • @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
  • @coderabbitai read src/utils.ts and explain its main purpose.
  • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
  • @coderabbitai help me debug CodeRabbit configuration file.

Support

Need help? Create a ticket on our support page for assistance with any issues or questions.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (Invoked using PR comments)

• @coderabbitai pause to pause the reviews on a PR.
• @coderabbitai resume to resume the paused reviews.
• @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
• @coderabbitai full review to do a full review from scratch and review all the files again.
• @coderabbitai summary to regenerate the summary of the PR.
• @coderabbitai generate docstrings to generate docstrings for this PR.
• @coderabbitai generate sequence diagram to generate a sequence diagram of the changes in this PR.
• @coderabbitai resolve resolve all the CodeRabbit review comments.
• @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
• @coderabbitai help to get help.

Other keywords and placeholders

• Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
• Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
• Add @coderabbitai anywhere in the PR title to generate the title automatically.

CodeRabbit Configuration File (.coderabbit.yaml)

• You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
• Please see the configuration documentation for more information.
• If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Documentation and Community

• Visit our Documentation for detailed information on how to use CodeRabbit.
• Join our Discord Community to get help, request features, and share feedback.
• Follow us on X/Twitter for updates and announcements.

[frzifus]

@coderabbitai explain this change.

[coderabbitai]

@frzifus This change switches the container's startup behavior from using CMD to ENTRYPOINT. Here's what this means:

Technical Difference

Before (CMD):

• CMD defines a default command that can be completely overridden at runtime
• Running docker run myimage some-other-command would execute some-other-command instead of the Python script

After (ENTRYPOINT):

• ENTRYPOINT defines a fixed executable that always runs
• Running docker run myimage --some-flag would execute python3.12 src/lightspeed_stack.py --some-flag

Practical Implications

1. More Predictable: The Python application (lightspeed_stack.py) will always be the main process, ensuring consistent container behavior

2. Better for Applications: Since this appears to be a web application (exposed on port 8080), using ENTRYPOINT ensures the application always starts, while allowing runtime arguments to be passed to it

3. Less Flexible: You can no longer override the entire command to run different executables in the container (e.g., for debugging with a shell)

Example Usage

# With CMD (old): This would run bash instead of Python
docker run myimage /bin/bash

# With ENTRYPOINT (new): This passes --help to the Python script
docker run myimage --help
# Executes: python3.12 src/lightspeed_stack.py --help

This change makes the container more application-focused and less general-purpose, which is typically preferred for production applications.

[tisnik]

@matysek PTAL

[matysek]

LGTM. Seems more secure for prod deployment.

[tisnik]

LGTM