fluent-plugin-label-router

Fluentd output plugin to route records based on their Kubernetes metadata.

Installation

RubyGems

$ gem install fluent-plugin-label-router

Specific install

$ gem install specific_install &&

Bundler

Add following line to your Gemfile:

gem "fluent-plugin-label-router"

And then execute:

$ bundle

Configuration

The configuration builds from <route> sections.

<match example.tag**>
  @type label_router
  <route>
     ...
  </route>
  <route>
     ...
  </route>
</match>

Parameter	Description	Default
labels	Label definition to match record. Example: app:nginx	nil
namespace	Namespaces definition to filter the record. Ignored if left empty.	""
@label	New @LABEL if selectors matched	nil
tag	New tag if selectors matched	""
emit_mode	Emit mode. If batch, the plugin will emit events per labels matched. Enum: record, batch	batch
sticky_tags	Sticky tags will match only one record from an event stream. The same tag will be treated the same way	true

Examples

1. Route specific labels and namespace to @label and new tag

Configuration to re-tag and re-label all logs from default namespace with label app=nginx and env=dev.

<match example.tag**>
  @type label_router
  <route>
     labels app:nginx,env:dev
     namespace default
     @label @NGINX
     tag new_tag
  </route>
</match>

Example records

Input

@label = ""; tag = "raw.input"; {"log" => "", "kubernetes" => { "namespace_name" => "default", "labels" =>  {"app" => "nginx", "env" => "dev" } } }
@label = ""; tag = "raw.input"; {"log" => "", "kubernetes" => { "namespace_name" => "kube-system", "labels" =>  {"app" => "tiller" } } }

Output

@label = "@NGINX"; tag = "new_tag"; {"log" => "", "kubernetes" => { "namespace_name" => "default", "labels" =>  {"app" => "nginx" } } }
nil

2. Both labels and namespace are optional

Only labels

<match example.tag**>
  @type label_router
  <route>
     labels app:nginx
     @label @NGINX
     tag new_tag
  </route>
</match>

Only namespace

<match example.tag**>
  @type label_router
  <route>
     namespace default
     @label @NGINX
     tag new_tag
  </route>
</match>

Rewrite all

<match example.tag**>
  @type label_router
  <route>
     @label @NGINX
     tag new_tag
  </route>
</match>

3. One of @label ot tag configuration should be specified

If you don't rewrite either of them fluent will likely to crash because it will reprocess the same messages again.

Copyright

• Copyright(c) 2019- Banzai Cloud
• License
  • Apache License, Version 2.0