YAML configuration files "Includes" broken on Windows OS

[sergey-chanaev]

Bug Report

According to the documentation (https://docs.fluentbit.io/manual/administration/configuring-fluent-bit/yaml/includes-section) I am trying to split YAML configuration file using includes in order to load multiple pipelines. It looks like this functionality is broken on a Windows-based operating system. I've tried a lot variants but it doesn't help.

fluent-bit --config fluent-bit.yaml --workdir "E:\fluent-bit"

fluent-bit.yaml

service:
  flush: 5
  daemon: false
  log_level: trace
  parsers_file: parsers.yaml

includes:
   - dpc-1.yaml

dpc-1.yaml

env:
  flush_interval: 1

Output log messages

[2025/12/16 23:02:17.411526100] [error] [D:\a\fluent-bit\fluent-bit\src\config_format\flb_cf_yaml.c:2909 errno=2] No such file or directory
[2025/12/16 23:02:17.411990100] [error] [config] including file 'dpc-1.yaml' at fluent-bit.yaml:12       
[2025/12/16 23:02:17.412026900] [error] yaml error
[2025/12/16 23:02:17.412089800] [error] configuration file contains errors, aborting.

Expected behavior
Same configuration on WSL (Debian) works as expected

Dec 16 23:23:17 S-Laptop fluent-bit[1260]:              Fluent Bit v4.2 – Direct Routes Ahead
Dec 16 23:23:17 S-Laptop fluent-bit[1260]:          Celebrating 10 Years of Open, Fluent Innovation!
Dec 16 23:23:17 S-Laptop fluent-bit[1260]: [2025/12/16 23:23:17.269163838] [ info] Configuration:
Dec 16 23:23:17 S-Laptop fluent-bit[1260]: [2025/12/16 23:23:17.269205908] [ info]  flush time     | 5.000000 seconds
Dec 16 23:23:17 S-Laptop fluent-bit[1260]: [2025/12/16 23:23:17.269212360] [ info]  grace          | 5 seconds

Your Environment

• Version used: 4.2.1
• Operating System and version: Win 11

Additional context
It seems that this is an issue with the cross-platform implementation of fluent-bit.

[patrick-stephens]

Does it work with absolute paths rather than relative ones? I recall some related issues around that so wonder if they got fixed for Linux only.

[sergey-chanaev]

Does it work with absolute paths rather than relative ones? I recall some related issues around that so wonder if they got fixed for Linux only.

On Windows if a relative path is specified - I've got "No such file or directory". If an absolute path is specified - "Invalid argument".

What is interesting is that in the parsers_file parameter - the relative path works perfectly on both Windows and Linux.

[patrick-stephens]

Can you provide the absolute path you're using? Remember you'll have to quote it if using anything YAML considers "special" so make sure you're doing that too.