Fluent Bit Plugin

The following repository provides the structure and build-system helpers to develop C dynamic plugins for Fluent Bit like inputs, filters and outputs.

Fluent Bit API development/usage is out of the scope of this article.

Requirements

Fluent Bit Source code, version >= 1.2
C compiler: GCC or Clang
CMake3

Getting Started

In the following steps we will build the example plugin provided called out_stdout2. As a first step get into the build/ directory:

$ cd build/

Now we will provide CMake (our build system) two important variables:

FLB_SOURCE: absolute path to source code of Fluent Bit.
PLUGIN_NAME: directory name of the project that we aim to build. Note that any plugin name must have it proper prefix as the example mentioned above.

Assuming that Fluent Bit source code is located at /tmp/fluent-bit and we will build out_stdout2, we will run CMake with the following options:

$ cmake -DFLB_SOURCE=/tmp/fluent-bit -DPLUGIN_NAME=out_stdout2 ../

then type ‘make’ to build the plugin:

$ make
Scanning dependencies of target flb-out_stdout2
[ 50%] Building C object out_stdout2/CMakeFiles/flb-out_stdout2.dir/stdout2.c.o
[100%] Linking C shared library ../flb-out_stdout2.so
[100%] Built target flb-out_stdout2

If you query the content of the current directory you will find the new shared library created:

$ ls -l *.so
-rwxr-xr-x 1 edsiper edsiper 17288 jun 20 16:33 flb-out_stdout2.so

that .so file is our dynamic plugin that now can be loaded from Fluent Bit through the plugins configuration file.

License

This program is under the terms of the Apache License v2.0.