TLDR: This repo creates statically-linked builds of Fluent Bit, shortly after they are released to the main repo. A multi-platform OCI image is available, as well as individual binaries.
I created this project because I wanted to use the latest version of Fluent Bit on my home router, which runs Alpine Linux on an ARM64 platform. Alpine can be a challenge due to using musl libc instead of glibc - I wanted a distribution of Fluent Bit that could be used similar to a Go binary, without any concern for the underlying libraries.
Since I was using Docker buildx to enable building on many platforms via GitHub Actions, I also realized that a docker container based on scratch has some benefits as well for people using Docker on embedded platforms, in that it is much smaller to download and has a smaller attack surface, though there is a tradeoff in security that comes from embedding the dependencies (see Security Considerations).
These images/binaries are built using the debian container image, which provides the compatibility needed to build successfully on all of Fluent Bit's supported architectures. Because these builds are statically linked, they represent a point-in-time version of the libraries which are linked into the build. If a vulnerability is discovered in a linked library, that vulnerability will persist until a new build is created against the patched library. Since builds are automated this may not occur until the next upstream release.
Since the typical use case for Fluent Bit is to read locally and make outgoing connections to deliver logs to a platform, this helps to mitigate remote code execution vulnerabilities.
The systemd input plugin is not presently supported due to a lack of availability of a static libsystemd library in Debian. This is documented in this Debian bug report but was not added due to lack of demand. In the future this support may be able to be added by compiling libsystemd as part of the build process.
The WASM and Lua functionality are disabled from version 2.0.0 onward as they break static linking by causing the build process to attempt to link shared libraries into the static object.