Getting Started
Verified against the v1.19 series. Commands assume a Unix shell with Ruby installed.
Prerequisites
- Ruby 3.2 or later (
fluentd.gemspec:28, README Prerequisites)
Install
gem install fluentdA first working setup
The README Quick Start gets you from install to a confirmed event in four commands (source 1).
Generate a sample configuration directory.
bashfluentd -s confStart Fluentd with that configuration in the background.
bashfluentd -c conf/fluent.conf &Send a test event.
fluent-catships with the gem and forwards a JSON record under the tag you give it.bashecho '{"json":"message"}' | fluent-cat debug.test
The generated conf/fluent.conf includes a <match debug.**> block using the stdout output, so the event prints to the terminal where Fluentd is running.
Verify it works
Look at the Fluentd output. A successful round trip prints a line tagged debug.test with your record, similar to:
2026-06-23 12:00:00.000000000 +0000 debug.test: {"json":"message"}If the event appears, input, routing, and output are all working.
Where to go next
For production concerns such as high availability, buffer tuning, secure forward with TLS, and Kubernetes deployment via fluent-operator or Helm, see the official documentation and the fluent GitHub organization (source 1).