Docker

Fluent Bit container images are available on Docker Hub ready for production usage. Current available images can be deployed in multiple architectures.

Quick Start

Get started by simply typing the following command:

docker run -ti cr.fluentbit.io/fluent/fluent-bit

Tags and Versions

The following table describes the tags that are available on Docker Hub fluent/fluent-bit repository:

It is strongly suggested that you always use the latest image of Fluent Bit.

Multi Architecture Images

Our production stable images are based on Distroless focusing on security containing just the Fluent Bit binary and minimal system libraries and basic configuration. We also provide debug images for all architectures (from 1.9.0+) which contain a full (Debian) shell and package manager that can be used to troubleshoot or for testing purposes.

From a deployment perspective, there is no need to specify an architecture, the container client tool that pulls the image gets the proper layer for the running architecture.

Getting Started

Download the last stable image from 1.9 series:

docker pull cr.fluentbit.io/fluent/fluent-bit:1.9

Once the image is in place, now run the following (useless) test which makes Fluent Bit measure CPU usage by the container:

docker run -ti cr.fluentbit.io/fluent/fluent-bit:1.9 \
  -i cpu -o stdout -f 1

That command will let Fluent Bit measure CPU usage every second and flush the results to the standard output, e.g:

[2019/10/01 12:29:02] [ info] [engine] started
[0] cpu.0: [1504290543.000487750, {"cpu_p"=>0.750000, "user_p"=>0.250000, "system_p"=>0.500000, "cpu0.p_cpu"=>0.000000, "cpu0.p_user"=>0.000000, "cpu0.p_system"=>0.000000, "cpu1.p_cpu"=>1.000000, "cpu1.p_user"=>0.000000, "cpu1.p_system"=>1.000000, "cpu2.p_cpu"=>1.000000, "cpu2.p_user"=>1.000000, "cpu2.p_system"=>0.000000, "cpu3.p_cpu"=>0.000000, "cpu3.p_user"=>0.000000, "cpu3.p_system"=>0.000000}]

F.A.Q

Why there is no Fluent Bit Docker image based on Alpine Linux ?

Alpine Linux uses Musl C library instead of Glibc. Musl is not fully compatible with Glibc which generated many issues in the following areas when used with Fluent Bit:

• Memory Allocator: to run Fluent Bit properly in high-load environments, we use Jemalloc as a default memory allocator which reduce fragmentation and provides better performance for our needs. Jemalloc cannot run smoothly with Musl and requires extra work.

• Alpine Linux Musl functions bootstrap have a compatibility issue when loading Golang shared libraries, this generate problems when trying to load Golang output plugins in Fluent Bit.

• Alpine Linux Musl Time format parser does not support Glibc extensions

• Maintainers preference in terms of base image due to security and maintenance reasons are Distroless and Debian.