build(ui): bump nginx to 1.31-alpine

[devin-ai-integration]

TLDR

Problem this solves:

• PR build(ui): bump nginx to 1.31-alpine #34831 (bump nginx to 1.31-alpine) has a merge conflict with litellm_internal_staging
• the base branch renamed NODE_VERSION to UI_BUILD_IMAGE in ui/Dockerfile, conflicting with the same lines
• the fork branch cannot be pushed to from here, so the conflict cannot be fixed in place

How it solves it:

• re-applies aharden's one line change (nginx 1.27-alpine -> 1.31-alpine) on current staging
• keeps the original author on the commit

User Flow

Before: an operator building the UI image gets nginx 1.27, which stopped receiving security updates on 24 Jun 2025

1. They run docker build -f ui/Dockerfile -t litellm-ui .
2. docker run --rm litellm-ui nginx -v prints nginx/1.27.x

After: the same build produces a supported nginx

1. They run docker build -f ui/Dockerfile -t litellm-ui .
2. docker run --rm litellm-ui nginx -v prints nginx/1.31.x

Relevant issues

Replaces #34831 (conflict resolution; original branch lives on a fork we cannot push to)

Linear ticket

Pre-Submission checklist

Please complete all items before asking a LiteLLM maintainer to review your PR

• I have added meaningful tests
• The handful of test files covering my change pass locally, e.g. uv run pytest tests/test_litellm/<your_test_file>.py -v. Leave the suites (make test-unit-*, make test-unit) to CI: it finishes in ~15 minutes where a laptop takes an hour or more
• My PR passes all required CI/CD checks (e.g., lint, schema.d.ts sync check, etc.)
• My PR's scope is as isolated as possible; it only solves 1 specific problem
• I have received a Greptile Confidence Score of at least 4/5 before requesting a maintainer review (Greptile reviews automatically once the PR is opened; only comment @greptileai to re-request a review after pushing changes)

Delays in PR merge?

If you're seeing a delay in your PR being merged, ping the LiteLLM Team on Slack (#pr-review).

Screenshots / Proof of Fix

The original PR carried a full docker build + curl proof (nginx -v prints 1.31.x, curl -I http://localhost:3000/ returns 200, clean startup logs). Docker Hub is blocked from this environment (network allowlist), so that run could not be repeated here; the change itself is the identical one line image tag bump, and Greptile scored the original 5/5

Type

🚄 Infrastructure

Caveats (if any)

Low

• proof of fix not re-run here: docker registry unreachable from this environment

Final Attestation

• The tests check the right things, including the edge cases, and regressions in the respective real-world customer use-cases are not possible after this PR

Link to Devin session: https://app.devin.ai/sessions/d62b9c8d88e64b89ac75a4581de4d98f
Open in Devin Desktop: https://app.devin.ai/desktop/session/d62b9c8d88e64b89ac75a4581de4d98f?variant=devin

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

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[devin-ai-integration]

PR #38541 (BerriAI/litellm, author devin-ai-integration[bot]) has no labels, so the required enterprise label is absent — out of scope. No GitHub or Linear changes made; no risk label applied and routing did not run.

[greptile-apps]

Greptile Summary

Updates the Admin UI runtime image from nginx 1.27-alpine to 1.31-alpine.

• Retains the existing multi-stage UI build and nginx runtime structure.
• Leaves nginx configuration, startup behavior, and application assets unchanged.

Confidence Score: 5/5

The PR appears safe to merge because the nginx version bump preserves the existing container contract and no actionable regression was identified.

The changed image tag is consumed by the existing nginx runtime stage, while the repository’s static-serving configuration and container test path remain compatible and unchanged.

Important Files Changed

Filename	Overview
ui/Dockerfile	Changes only the nginx runtime release tag; no concrete build, startup, serving, or repository-rule regression was identified.

_{Reviews (1): Last reviewed commit: "build(ui): bump nginx to 1.31-alpine" | Re-trigger Greptile}