[Bugfix] lmcache server points to wrong file in entrypoint

[Senne-Mennes]

Bug/fix is described in the issue below

FIX #676

BEFORE SUBMITTING, PLEASE READ THE CHECKLIST BELOW AND FILL IN THE DESCRIPTION ABOVE

---

• Make sure the code changes pass the pre-commit checks.
• Sign-off your commit by using -s when doing git commit
• Try to classify PRs for easy understanding of the type of changes, such as [Bugfix], [Feat], and [CI].

Detailed Checklist (Click to Expand)

Thank you for your contribution to production-stack! Before submitting the pull request, please ensure the PR meets the following criteria. This helps us maintain the code quality and improve the efficiency of the review process.

PR Title and Classification

Please try to classify PRs for easy understanding of the type of changes. The PR title is prefixed appropriately to indicate the type of change. Please use one of the following:

• [Bugfix] for bug fixes.
• [CI/Build] for build or continuous integration improvements.
• [Doc] for documentation fixes and improvements.
• [Feat] for new features in the cluster (e.g., autoscaling, disaggregated prefill, etc.).
• [Router] for changes to the vllm_router (e.g., routing algorithm, router observability, etc.).
• [Misc] for PRs that do not fit the above categories. Please use this sparingly.

Note: If the PR spans more than one category, please include all relevant prefixes.

Code Quality

The PR need to meet the following code quality standards:

• Pass all linter checks. Please use pre-commit to format your code. See README.md for installation.
• The code need to be well-documented to ensure future contributors can easily understand the code.
• Please include sufficient tests to ensure the change is stay correct and robust. This includes both unit tests and integration tests.

DCO and Signed-off-by

When contributing changes to this project, you must agree to the DCO. Commits must include a Signed-off-by: header which certifies agreement with the terms of the DCO.

Using -s with git commit will automatically add this header.

What to Expect for the Reviews

We aim to address all PRs in a timely manner. If no one reviews your PR within 5 days, please @-mention one of YuhanLiu11
, Shaoting-Feng or ApostaC.

[gemini-code-assist]

Summary of Changes

Hello @Senne-Mennes, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request resolves a bug in the Helm chart for the lmcache server where the deployment's entrypoint command was incorrectly specified or conditionally chosen, leading to the server potentially pointing to the wrong executable. The change simplifies the configuration by removing the conditional logic and standardizing the command to ensure the correct lmcache_server binary is always executed, addressing the reported issue.

Highlights

• Bugfix for lmcache server entrypoint: Corrects an issue where the lmcache server deployment was configured to use an incorrect binary or an experimental one under certain conditions.
• Simplified Helm deployment: Removes conditional logic in helm/templates/deployment-cache-server.yaml that previously determined the lmcache server's entrypoint based on the image tag.
• Standardized server command: Ensures the lmcache server consistently uses "/opt/venv/bin/lmcache_server" as its entrypoint, regardless of the cacheserverSpec.tag.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request addresses a bug where the lmcache server entrypoint in the Helm chart pointed to an incorrect file depending on the image tag. The change simplifies the deployment-cache-server.yaml by removing the conditional logic that selected different server executables. Now, it consistently uses /opt/venv/bin/lmcache_server. This not only fixes the bug but also improves maintainability by removing unnecessary complexity and path inconsistencies from the template. The change is correct and a good improvement.

[zerofishnoodles]

Hi, I don't see why it can be compatible with the version before v3.0.0. Maybe add some if-else?

[Senne-Mennes]

I tested which containers, that are available on DockerHub, had the old "lmcache_experimental_server", and made and if-else based on that. I assume future container tags will still be vx.x.x or nightly-20xx-xx-xx and use the new "/opt/venv/bin/lmcache_server".

test results specifically had the change happen at these containers

Testing: lmcache/vllm-openai:2025-05-08-v1
  ✓ NEW PATH: /opt/venv/bin/lmcache_server EXISTS
  ✗ OLD CMD: 'lmcache_experimental_server' NOT in PATH

Testing: lmcache/vllm-openai:2025-05-05-v1
  ✗ NEW PATH: /opt/venv/bin/lmcache_server NOT FOUND
  ✓ OLD CMD: 'lmcache_experimental_server' found in PATH
    Location: /usr/local/bin/lmcache_experimental_server

I've also included edge cases for the tag "test" and "vllm-cpu-env"

[zerofishnoodles]

Hi, I asked the team and they said no one is using the previous version now, can you just use the"/opt/venv/bin/lmcache_server"? Sorry for the misleading information before.

[Senne-Mennes]

Hi, just using "/opt/venv/bin/lmcache_server" now

[zerofishnoodles]

LGTM