fix(util): preserve empty container slots in Ascend device index mapping

[manoj-1407]

What type of PR is this?

/kind bug

Which issue(s) this PR fixes

Fixes #123

What this PR does

Ascend and Ascend310P device decoding silently skipped empty container entries, breaking the container-to-device index mapping for multi-container pods.

For a 2-container pod where container-0 has no Ascend device and container-1 does, the device was incorrectly mapped to container-0.

The Problem

// Before: silently skips empty entries, corrupts index mapping
if len(cd) == 0 {
    continue
}

NVIDIA, Hygon, and MetaX all correctly preserve empty slots. Ascend was the only device type missing this.

The Fix

Mirrors the existing pattern used by NVIDIA/Hygon/MetaX — check container count bound and append ContainerDevices{} for empty segments.

Testing

Added TestDecodePodDevicesAscendMultiContainer which proves the correct index mapping is preserved. All existing tests pass.

AI Disclosure

Used Claude for guidance. Did all implementation and testing myself. Understand the fix completely.

Summary by CodeRabbit

• Bug Fixes

  • Improved Ascend device decoding for pods with multiple containers.
  • Preserved empty container positions and skipped empty device annotations.
  • Continued to report decoding failures safely without returning partial results.

• Tests

  • Added coverage for multi-container pods where devices are assigned only to the appropriate container.

[hami-robot]

@manoj-1407: The label(s) kind/bug cannot be applied, because the repository doesn't have them.

Details

In response to this:

What type of PR is this?

/kind bug

What this PR does

Ascend and Ascend310P device decoding silently skipped empty container entries, breaking the container-to-device index mapping for multi-container pods.

For a 2-container pod where container-0 has no Ascend device and container-1 does, the device was incorrectly mapped to container-0.

The Problem

// Before: silently skips empty entries, corrupts index mapping
if len(cd) == 0 {
   continue
}

NVIDIA, Hygon, and MetaX all correctly preserve empty slots. Ascend was the only device type missing this.

The Fix

Mirrors the existing pattern used by NVIDIA/Hygon/MetaX — check container count bound and append ContainerDevices{} for empty segments.

Testing

Added TestDecodePodDevicesAscendMultiContainer which proves the correct index mapping is preserved. All existing tests pass.

AI Disclosure

Used Claude for guidance. Did all implementation and testing myself. Understand the fix completely.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[hami-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: manoj-1407

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[hami-robot]

Welcome @manoj-1407! It looks like this is your first PR to Project-HAMi/HAMi-WebUI 🎉

[coderabbitai]

📝 Walkthrough

Walkthrough

Ascend pod-device decoding now bounds annotation processing by container count, preserves empty container positions, skips empty segments, and retains error handling. A multi-container test verifies the new mapping behavior.

Changes

Ascend container decoding

Layer / File(s)	Summary
Preserve Ascend container slots server/internal/provider/util/util.go, server/internal/provider/util/util_test.go	DecodePodDevices preserves empty container entries, limits processing to the pod container count, and decodes non-empty segments. The test verifies two container slots with a device only in the second slot.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• Project-HAMi/HAMi-WebUI#95: Both changes preserve Ascend container positions and bound decoding by container count.
• Project-HAMi/HAMi-WebUI#104: Both changes modify DecodePodDevices for multi-container device annotations.
• Project-HAMi/HAMi-WebUI#119: Both changes preserve empty Ascend container entries during decoding.

Suggested reviewers: fouof

Poem

A rabbit checks each container row,
Empty slots stay empty in the flow.
Devices hop where annotations say,
Errors still turn the result away.
Ascend’s mapping now stays in array!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main Ascend device mapping fix for empty container slots.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[Nimbus318]

Thanks for identifying and testing the container-slot alignment bug. The same fix is now included in merged #95, together with multi-device-type aggregation coverage, so this PR is superseded.