Correct partition index loop in butane/*/translate.go

[skewballfox]

patching work from PR 722 for butane.

currently trying to override the default sizes for the boot partitions.

In my butain file, I have:

        - number: 1
          label: bios
          size_mib: 1
          type_guid: 21686148-6449-6E6F-744E-656564454649
        - number: 2
          label: efi 
          size_mib: 1024
          type_guid: C12A7328-F81F-11D2-BA4B-00A0C93EC93B
          wipe_partition_entry: true
        - number: 3
          label: boot
          size_mib: 2048
          type_guid: 0FC63DAF-8483-4772-8E79-3D69D8477DE4
          wipe_partition_entry: true
        - label: root
          number: 4
          wipe_partition_entry: true
          type_guid: 4F68BCE3-E8CD-4DB1-96E7-FBCAF984B709

which should be valid. root is the last partition, and all the others have a set size. currently this throws:

     |                  ^^^^ root partition cannot expand; it is set to fill available space but is followed by an auto-positioned partition
 122 |           number: 4
 123 |           start_mib: 0
     |
Config produced warnings and --strict was specified

this shoud only check the partitions after root

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📥 Commits

Reviewing files that changed from the base of the PR and between 9e2b242 and 594667e.

📒 Files selected for processing (14)

• butane/config/fcos/v1_3/translate.go
• butane/config/fcos/v1_3/translate_test.go
• butane/config/fcos/v1_4/translate.go
• butane/config/fcos/v1_4/translate_test.go
• butane/config/fcos/v1_5/translate.go
• butane/config/fcos/v1_5/translate_test.go
• butane/config/fcos/v1_6/translate.go
• butane/config/fcos/v1_6/translate_test.go
• butane/config/fcos/v1_7/translate.go
• butane/config/fcos/v1_7/translate_test.go
• butane/config/fcos/v1_8_exp/translate.go
• butane/config/fcos/v1_8_exp/translate_test.go
• butane/docs/release-notes.md
• docs/release-notes.md

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docs/**

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docs/**: Documentation served via GitHub Pages/Jekyll. Every platform must be documented in supported-platforms.md. The ./test script validates doc consistency.

Files:

• docs/release-notes.md

**/*.go

📄 CodeRabbit inference engine (AGENTS.md)

**/*.go: Include the required Apache 2.0 license header at the top of every Go source file.
Use the project's import ordering in Go files: standard library imports, blank line, project packages, blank line, then external dependencies.
Follow the project's Go naming conventions: exported identifiers use PascalCase, unexported identifiers use camelCase, and filenames use snake_case.

Files:

• butane/config/fcos/v1_8_exp/translate_test.go
• butane/config/fcos/v1_6/translate_test.go
• butane/config/fcos/v1_3/translate_test.go
• butane/config/fcos/v1_7/translate_test.go
• butane/config/fcos/v1_8_exp/translate.go
• butane/config/fcos/v1_6/translate.go
• butane/config/fcos/v1_5/translate.go
• butane/config/fcos/v1_3/translate.go
• butane/config/fcos/v1_4/translate_test.go
• butane/config/fcos/v1_5/translate_test.go
• butane/config/fcos/v1_4/translate.go
• butane/config/fcos/v1_7/translate.go

🔇 Additional comments (14)

butane/config/fcos/v1_3/translate.go (1)

78-78: LGTM!

butane/config/fcos/v1_3/translate_test.go (1)

1655-1685: LGTM!

butane/config/fcos/v1_4/translate.go (1)

78-78: LGTM!

butane/config/fcos/v1_4/translate_test.go (1)

1655-1685: LGTM!

butane/config/fcos/v1_5/translate.go (1)

79-79: LGTM!

butane/config/fcos/v1_5/translate_test.go (1)

1737-1767: LGTM!

docs/release-notes.md (1)

22-22: LGTM!

butane/config/fcos/v1_6/translate.go (1)

79-79: LGTM!

butane/config/fcos/v1_6/translate_test.go (1)

1737-1767: LGTM!

butane/config/fcos/v1_7/translate.go (1)

79-79: LGTM!

butane/config/fcos/v1_7/translate_test.go (1)

1738-1768: LGTM!

butane/config/fcos/v1_8_exp/translate.go (1)

79-79: LGTM!

butane/config/fcos/v1_8_exp/translate_test.go (1)

1884-1914: LGTM!

butane/docs/release-notes.md (1)

24-24: LGTM!

---

📝 Walkthrough

Walkthrough

Root partition constraint checks across FCOS versions 1.3 through 1.8 experimental now inspect only partitions after the root partition. Regression tests cover unsized root partitions placed last, and release notes document the fix.

Changes

Root partition constraint handling

Layer / File(s)	Summary
Constraint validation and regression tests butane/config/fcos/v1_3/..., butane/config/fcos/v1_4/..., butane/config/fcos/v1_5/..., butane/config/fcos/v1_6/..., butane/config/fcos/v1_7/..., butane/config/fcos/v1_8_exp/...	Root partition validation skips preceding partitions and retains checks for following partitions. Tests cover final unsized root partitions with explicitly sized preceding partitions.
Release note updates butane/docs/release-notes.md, docs/release-notes.md	Release notes document the root partition constraint fix, and the Butane release-notes section gains spacing.

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

Merge Risk: ⚪ Minimal · up to 59466

This change corrects partition-index validation so a final expandable root partition is handled correctly across supported configuration versions. No actionable merge-blocking risk remains beyond normal checks and review.

Suggested reviewers: prestist

🚥 Pre-merge checks | ✅ 5 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Title check	⚠️ Warning	The title describes the partition loop fix but does not follow the required subsystem: lowercase description format or imperative lowercase styling.	Use a title such as "config/*: correct partition index loop" with a subsystem prefix and lowercase description.

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description check	✅ Passed	The description explains the root partition validation issue, provides a reproduction, and matches the stated objectives.
Docstring Coverage	✅ Passed	Docstring check was indeterminate for this PR — some files could not be analyzed in time. Not blocking.
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.
Commit Message Convention	✅ Passed	The PR has one non-merge commit, and its subject uses a subsystem prefix, starts the description with imperative lowercase “fix,” and has no trailing period.

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[github-actions]

Binary size report (bin/amd64/ignition)

	Size
Base (main)	33MiB
PR (#2304)	33MiB
Delta	+64B (0.00%)