bin: Use proper ISO 8601 format for logging

[michael-o]

Instead of using a custom format, use proper extended ISO 8601 datetime format.

Change is straight forward. Output now:

root@135-release-amd64-default-head:/usr/ports/sysutils/fluent-bit # fluent-bit
Fluent Bit v4.2.2
* Copyright (C) 2015-2025 The Fluent Bit Authors
* Fluent Bit is a CNCF graduated project under the Fluent organization
* https://fluentbit.io

______ _                  _    ______ _ _             ___   _____
|  ___| |                | |   | ___ (_) |           /   | / __  \
| |_  | |_   _  ___ _ __ | |_  | |_/ /_| |_  __   __/ /| | `' / /'
|  _| | | | | |/ _ \ '_ \| __| | ___ \ | __| \ \ / / /_| |   / /
| |   | | |_| |  __/ | | | |_  | |_/ / | |_   \ V /\___  |_./ /___
\_|   |_|\__,_|\___|_| |_|\__| \____/|_|\__|   \_/     |_(_)_____/

             Fluent Bit v4.2 – Direct Routes Ahead
         Celebrating 10 Years of Open, Fluent Innovation!

[2026-02-14 16:48:08.479196279] [ info] [fluent bit] version=4.2.2, commit=, pid=51299
[2026-02-14 16:48:08.479304309] [ info] [storage] ver=1.5.4, type=memory, sync=normal, checksum=off, max_chunks_up=128
[2026-02-14 16:48:08.479316303] [ info] [simd    ] disabled
[2026-02-14 16:48:08.479331868] [ info] [cmetrics] version=1.0.6
[2026-02-14 16:48:08.479341850] [ info] [ctraces ] version=0.6.6
[2026-02-14 16:48:08.479426082] [ info] [sp] stream processor started
[2026-02-14 16:48:08.479455774] [ info] [engine] Shutdown Grace Period=5, Shutdown Input Grace Period=2
^C[2026/02/14 16:48:14] [engine] caught signal (SIGINT)
[2026-02-14 16:48:14.437349155] [ warn] [engine] service will shutdown in max 5 seconds
[2026-02-14 16:48:14.437375002] [ info] [engine] pausing all inputs..
[2026-02-14 16:48:15.437451218] [ info] [engine] service has stopped (0 pending tasks)
root@135-release-amd64-default-head:/usr/ports/sysutils/fluent-bit #

Summary by CodeRabbit

• Style
  • Standardized date separator in visible timestamps from YYYY/MM/DD to YYYY-MM-DD across runtime logs, dump headers, and status/signal messages, producing consistent hyphen-separated dates in emitted logs and diagnostics without changing log content or behavior.

[coderabbitai]

📝 Walkthrough

Walkthrough

Date separators in log and dump timestamp format strings were changed from slashes (/) to dashes (-) across three source files; no other logic, control flow, or API changes were made.

Changes

Cohort / File(s)	Summary
Date format updates src/flb_log.c, src/flb_dump.c, src/fluent-bit.c	Replaced '/' with '-' in timestamp/date format strings used for log, dump, and signal/status prefixes (e.g., YYYY/MM/DD -> YYYY-MM-DD). No functional, error-handling, or API changes.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• edsiper

Poem

🐰 A tiny hop to tweak the date,
Slashes swapped so logs look straight,
Dashes line the morning light,
Timestamps tidy, neat, and bright,
I nibble code — and dance with delight!

🚥 Pre-merge checks | ✅ 2 | ❌ 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 (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately reflects the main change: updating timestamp format across logging components to use ISO 8601 standard with hyphens instead of slashes in the date portion.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: 7c429e5ee1

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[coderabbitai]

🧹 Nitpick comments (1)

src/flb_log.c (1)

731-731: LGTM — correct date separator change.

The YYYY-MM-DD date format is a direct improvement over the previous slash-separated form. One optional note in the context of the PR's stated goal: the resulting format YYYY-MM-DD HH:MM:SS.nnn uses a space rather than T as the date-time separator. Strict ISO 8601 extended format requires T (e.g., 2026-02-14T16:48:08.479196279). RFC 3339 permits space as a human-readable substitute, so this is a deliberate trade-off rather than a bug.

🔎 If strict ISO 8601 is the goal, consider `T` as separator

-                   "%s[%s%i-%02i-%02i %02i:%02i:%02i.%03ld%s]%s [%s%5s%s] ",
+                   "%s[%s%i-%02i-%02iT%02i:%02i:%02i.%03ld%s]%s [%s%5s%s] ",

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/flb_log.c` at line 731, The log timestamp format currently uses a space
between date and time in the format string ("%s[%s%i-%02i-%02i
%02i:%02i:%02i.%03ld%s]%s ..."); if you want strict ISO 8601 compliance change
the separator to 'T' in that format string (i.e., replace the space between the
date and time fields with 'T') so the produced timestamp reads
YYYY-MM-DDTHH:MM:SS.nnn; update the format literal in src/flb_log.c where that
string appears.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@src/flb_log.c`:
- Line 731: The log timestamp format currently uses a space between date and
time in the format string ("%s[%s%i-%02i-%02i %02i:%02i:%02i.%03ld%s]%s ...");
if you want strict ISO 8601 compliance change the separator to 'T' in that
format string (i.e., replace the space between the date and time fields with
'T') so the produced timestamp reads YYYY-MM-DDTHH:MM:SS.nnn; update the format
literal in src/flb_log.c where that string appears.

[cosmo0920]

This change could break backward compatibility. So, do we need to provide a service parameter to turn on using ISO 8601 format on log?
This can make a room to merge, I suppose.

[michael-o]

This change could break backward compatibility. So, do we need to provide a service parameter to turn on using ISO 8601 format on log? This can make a room to merge, I suppose.

If so, I would make if fully compliant. Unfortunately, I have no idea how to introduce a flag for this.
Do you anticipate people parsing the log output?