Add retry logic for singularity pull failures

[yarikoptic]

Retry singularity pull operations that fail with exit code 255, which typically indicates network-related issues (unexpected EOF, timeouts, connection failures). Uses exponential backoff with up to 3 attempts. Cleans up partial downloads between retries and logs progress for visibility.

[gemini-code-assist]

Summary of Changes

Hello @yarikoptic, 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 significantly enhances the reliability of Singularity image acquisition by introducing a robust retry mechanism. It specifically targets transient network-related failures, identified by exit code 255, ensuring that singularity pull operations are more resilient to intermittent connectivity issues. By implementing exponential backoff and cleaning up partial downloads, the change aims to reduce build failures and improve the overall stability of image creation processes.

Highlights

• Retry Logic for Singularity Pulls: Implemented a retry mechanism for singularity pull operations that fail due to specific error conditions.
• Targeted Error Handling: Retries are specifically triggered when singularity pull exits with code 255, which commonly indicates network-related issues such as unexpected EOF, timeouts, or connection failures.
• Exponential Backoff: The retry logic utilizes an exponential backoff strategy, attempting the pull up to 3 times with increasing delays between attempts.
• Partial Download Cleanup: Between retry attempts, any partially downloaded .sif.tmp files are automatically cleaned up to ensure a fresh start for the next pull attempt.
• Improved Logging: Added informative warning messages for each retry attempt and a final error message if all attempts fail, providing better visibility into the pull process.

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Changelog

• scripts/create_singularities
  • Added a while True loop with a try-except block around the singularity pull command to implement retry logic.
  • Configured max_attempts to 3 and integrated an exp_wait function for exponential backoff between retries.
  • Modified error handling to specifically catch subprocess.CalledProcessError and retry only if e.returncode is 255.
  • Included tmpfile.unlink() within the retry logic to clean up partial downloads before subsequent attempts.
  • Added log.warning messages for retry attempts and log.error for final failures to provide better operational visibility.

Activity

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[gemini-code-assist]

Code Review

This pull request introduces valuable retry logic for singularity pull operations, which will improve robustness against transient network failures. My review focuses on enhancing the clarity of the retry mechanism and ensuring that temporary files are cleaned up correctly under all failure conditions to prevent orphaned files.

[Copilot]

Pull request overview

This PR adds retry logic to the singularity pull operation to handle transient network failures. When singularity pull fails with exit code 255 (typically indicating network issues like EOF or timeouts), the code now automatically retries with exponential backoff instead of failing immediately. Partial downloads are cleaned up between retry attempts, and progress is logged for visibility.

Changes:

• Added retry loop with exponential backoff for singularity pull operations
• Implemented cleanup of partial downloads between retries
• Added logging for retry attempts and failures

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[yarikoptic]

there is fails due to shell check... will push those