Kernel logs

The kmsg input plugin reads the Linux Kernel log buffer from the beginning. It gets every record and parses fields as priority, sequence, seconds, useconds, and message.

Configuration parameters

Key	Description	Default
Prio_Level	The log level to filter. The kernel log is dropped if its priority is more than prio_level. Allowed values are 0-8. 8 means all logs are saved.	8
Threaded	Indicates whether to run this input in its own thread.	false

Get started

To start getting the Linux Kernel messages, you can run the plugin from the command line or through the configuration file:

Command line

fluent-bit -i kmsg -t kernel -o stdout -m '*'

Which returns output similar to:

...
[0] kernel: [1463421823, {"priority"=>3, "sequence"=>1814, "sec"=>11706, "usec"=>732233, "msg"=>"ERROR @wl_cfg80211_get_station : Wrong Mac address, mac = 34:a8:4e:d3:40:ec profile =20:3a:07:9e:4a:ac"}]
[1] kernel: [1463421823, {"priority"=>3, "sequence"=>1815, "sec"=>11706, "usec"=>732300, "msg"=>"ERROR @wl_cfg80211_get_station : Wrong Mac address, mac = 34:a8:4e:d3:40:ec profile =20:3a:07:9e:4a:ac"}]
[2] kernel: [1463421829, {"priority"=>3, "sequence"=>1816, "sec"=>11712, "usec"=>729728, "msg"=>"ERROR @wl_cfg80211_get_station : Wrong Mac address, mac = 34:a8:4e:d3:40:ec profile =20:3a:07:9e:4a:ac"}]
[3] kernel: [1463421829, {"priority"=>3, "sequence"=>1817, "sec"=>11712, "usec"=>729802, "msg"=>"ERROR @wl_cfg80211_get_station : Wrong Mac address, mac = 34:a8:4e:d3:40:ec
...

As described previously, the plugin processed all messages that the Linux Kernel reported. The output has been truncated for clarification.

Configuration file

In your main configuration file append the following:

fluent-bit.yaml

pipeline:
  inputs:
    - name: kmsg
      tag: kernel

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

[INPUT]
  Name   kmsg
  Tag    kernel

[OUTPUT]
  Name   stdout
  Match  *