fix(kind): set containerd LimitNOFILE to 4096 to avoid valgrind failure

[oilbeater]

Summary

• Set LimitNOFILE=4096 for containerd on all Kind nodes after cluster creation
• The default LimitNOFILE=infinity causes valgrind to fail with:

  libcfile Valgrind: FATAL: Private file creation failed.
  The current file descriptor limit is 1073741804.
  If you are running in Docker please consider
  lowering this limit with the shell built-in limit command.
  Exiting now.
  

Test plan

• Run make kind-init to create cluster
• Verify LimitNOFILE=4096 on all nodes: docker exec <node> grep LimitNOFILE /etc/systemd/system/containerd.service
• Verify containerd is active: docker exec <node> systemctl status containerd

🤖 Generated with Claude Code

[gemini-code-assist]

Summary of Changes

Hello @oilbeater, 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 critical issue where valgrind operations would fail within Kind clusters due to an excessively high default file descriptor limit for containerd. By programmatically setting a specific LimitNOFILE value, the stability and compatibility of the Kind environment for testing and development are significantly improved, preventing common libcfile errors.

Highlights

• Containerd Configuration: The LimitNOFILE setting for containerd is now explicitly set to 4096 on all Kind nodes after cluster creation.
• Valgrind Compatibility: This change addresses a fatal valgrind error that occurred due to the default LimitNOFILE=infinity setting, which caused private file creation to fail.

Changelog

• makefiles/kind.mk
  • Added a loop to iterate through all Kind nodes after cluster creation.
  • Introduced commands to modify the containerd.service file on each node, changing LimitNOFILE=infinity to LimitNOFILE=4096.
  • Included steps to reload the systemd daemon and restart the containerd service on each node to apply the new limit.

Activity

• The pull request was generated using Claude Code, indicating an AI-assisted creation process.

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[gemini-code-assist]

Code Review

This pull request effectively resolves the valgrind failure by correctly adjusting the LimitNOFILE setting for containerd on Kind nodes. The changes ensure that the containerd service is reconfigured and restarted after cluster creation, which directly addresses the problem described.

[gemini-code-assist]

Using sed -i to modify systemd service files can be brittle. If the format or content of /etc/systemd/system/containerd.service changes in a future update, the sed command might fail or produce unintended results. A more robust approach is to create a systemd drop-in file (override.conf) to apply specific settings. This method ensures that your changes are preserved and applied correctly, even if the main service file is updated.

		docker exec $$node mkdir -p /etc/systemd/system/containerd.service.d; docker exec $$node sh -c 'echo -e "[Service]\nLimitNOFILE=4096" > /etc/systemd/system/containerd.service.d/override.conf'; \