filter_log_to_metrics: fix initialization and exception cleanup

[edsiper]

• processor: fix handling of numeric values in config map
• filter: validate NULL values in properties
• filter_log_to_metrics: fix initialization and exception cleanup

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Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

Summary by CodeRabbit

• New Features

  • Extended processor unit configuration to support numeric array elements (integers, unsigned integers, and floating-point numbers) alongside existing string support.

• Bug Fixes

  • Added defensive validation to prevent crashes from null values in property operations.
  • Improved error handling and lifecycle management in the metrics logging pipeline for better stability.

[coderabbitai]

📝 Walkthrough

Walkthrough

Refactors error handling lifecycle in the log_to_metrics plugin by consolidating context cleanup paths, adds NULL-safety checks in filter property setting, and extends processor unit property handling to accept numeric array elements with automatic string conversion.

Changes

Cohort / File(s)	Summary
Log-to-Metrics Plugin Lifecycle plugins/filter_log_to_metrics/log_to_metrics.c	Restructures context initialization and cleanup flow: removes redundant intermediate destroy calls on error paths, sets context early via flb_filter_set_context, adds NULL guard in exit callback, and initializes ctx->rules earlier in initialization sequence.
Filter Property Setting src/flb_filter.c	Adds defensive NULL check for value parameter in flb_filter_set_property before string translation, returning error code if NULL is passed.
Processor Array Element Type Support src/flb_processor.c	Extends processor unit property array handling to accept numeric types (int, uint, double) alongside strings; converts numeric elements to strings via snprintf for property setting, with error logging for unsupported types.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• log_to_metrics: fix improper handling of record accessor context #10920: Modifies log_to_metrics plugin context initialization and lifecycle management patterns, including persistent value_ra creation in init phase.

Suggested labels

backport to v4.0.x

Suggested reviewers

• koleini
• fujimotos

Poem

A filter's life, once tangled, now clean,
NULL guards stand watch where crashes had been,
Numbers transform to strings in a dance,
Lifecycle flows with improved stance—
Defensive and tidy, our code takes its chance! 🐰✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 20.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'filter_log_to_metrics: fix initialization and exception cleanup' directly and clearly describes the main change in the primary modified file (plugins/filter_log_to_metrics/log_to_metrics.c), focusing on the refactored error handling and lifecycle management.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch processor-log_to_metrics

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[chatgpt-codex-connector]

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Reviewed commit: 839c07c993

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