feat(BA-858): Set Docker container timezone using TZ env

[studioego]

Set Docker container timezone using TZ env

• configure Docker container timezone consistently across any Linux distributions & Mac hosts
• implement platform-independent solution using environment variables (e.g. ENV TZ=Asia/Seoul )

Ref1: Synchronize timezone from host to container
https://forums.docker.com/t/synchronize-timezone-from-host-to-container/39116/1

resolves #2300 #3841

Checklist: (if applicable)

• Milestone metadata specifying the target backport version
• [V] Mention to the original issue
• Installer updates including:
  • Fixtures for db schema changes
  • New mandatory config options
• Update of end-to-end CLI integration tests in ai.backend.test
• API server-client counterparts (e.g., manager API -> client SDK)
• Test case(s) to:
  • Demonstrate the difference of before/after
  • Demonstrate the flow of abstract/conceptual models with a concrete implementation
• Documentation
  • Contents in the docs directory
  • docstrings in public interfaces and type annotations

[Copilot]

PR Overview

This PR implements a platform‐independent solution for setting the Docker container's timezone using the TZ environment variable. The changes include adding a new helper function to extract timezone information from the host's localtime file, and removing the bind mount configuration for /etc/localtime and /etc/timezone in the Docker agent.

Reviewed Changes

File	Description
src/ai/backend/agent/agent.py	Adds adjust_zoneinfo_string to derive timezone info and injects TZ
src/ai/backend/agent/docker/agent.py	Removes bind mount logic for /etc/localtime and /etc/timezone

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/ai/backend/agent/agent.py:209

• [nitpick] Using a magic index value of -3 can be unclear. Recommend using a named constant or expanding the comment to clarify its purpose.

idx = -3  # /usr/share/zoneinfo.default/Asia/Seoul

[Copilot]

On non-darwin platforms, if 'zoneinfo' is not present in host_path parts, this code will raise a ValueError. Consider adding error handling or an alternative fallback path.

Suggested change

	idx = parts.index("zoneinfo")
	try:
	idx = parts.index("zoneinfo")
	except ValueError:
	raise ValueError("The 'zoneinfo' directory is not present in the provided host_path.")