This repository contains the Fluentd Papertrail Output Plugin.

Install this gem when setting up fluentd:

gem install fluent-plugin-papertrail

This plugin connects to Papertrail log destinations over TCP+TLS. This connection method should be enabled by default in standard Papertrail accounts, see:

papertrailapp.com > Settings > Log Destinations

To configure this in fluentd:

<match whatever.*>
  type papertrail
  papertrail_host <your papertrail hostname>
  papertrail_port <your papertrail port>
</match>

This plugin expects the following fields to be set for each Fluent record:

    message   The log
    program   The program/tag
    severity  A valid syslog severity label
    facility  A valid syslog facility label
    hostname  The source hostname for papertrail logging

The following example is a record_transformer filter, from the Kubernetes assets in the Solarwinds fluentd-deployment repo, that is used along with the fluent-plugin-kubernetes_metadata_filter to populate the required fields for our plugin:

<filter kubernetes.**>
  type kubernetes_metadata
</filter>

<filter kubernetes.**>
  type record_transformer
  enable_ruby true
  <record>
    hostname ${record["kubernetes"]["namespace_name"]}-${record["kubernetes"]["pod_name"]}
    program ${record["kubernetes"]["container_name"]}
    severity info
    facility local0
    message ${record['log']}
  </record>
</filter>

If you don't set hostname and program values in your record, they will default to the environment variable FLUENT_HOSTNAME or 'unidentified' and the fluent tag, respectively.

This plugin inherits a few useful config parameters from Fluent's BufferedOutput class.

Parameters for flushing the buffer, based on size and time, are buffer_chunk_limit and flush_interval, respectively. This plugin overrides the inherited default flush_interval to 1, causing the fluent buffer to flush to Papertrail every second.

If the plugin fails to write to Papertrail for any reason, the log message will be put back in Fluent's buffer and retried. Retrying can be tuned and inherits a default configuration where retry_wait is set to 1 second and retry_limit is set to 17 attempts.

If you want to change any of these parameters simply add them to a match stanza. For example, to flush the buffer every 60 seconds and stop retrying after 2 attempts, set something like:

<match whatever.*>
  type papertrail
  papertrail_host <your papertrail hostname>
  papertrail_port <your papertrail port>
  flush_interval 60
  retry_limit 2
</match>

If you're running this plugin in Kubernetes with the kubernetes_metadata_filter plugin enabled you can redirect logs to alternate Papertrail destinations by adding annotations to your Pods or Namespaces:

solarwinds.io/papertrail_host: 'logs0.papertrailapp.com'
solarwinds.io/papertrail_port: '12345'

If both the Pod and Namespace have annotations for any running Pod, the Pod's annotation is used.

This plugin is targeting Ruby 2.4 and Fluentd v1.0, although it should work with older versions of both.

We have a Makefile to wrap common functions and make life easier.

make bundle

make test

To release a new version, update the version number in the GemSpec and then, run:

make release

Bug reports and pull requests are welcome on GitHub at: https://github.com/solarwinds/fluent-plugin-papertrail

The gem is available as open source under the terms of the Apache License.

Please open an issue, we'd love to hear from you.